Filter element and filter device

Abstract

The invention relates to a filter element (10), in particular an air filter element, having two filter bellows (1, 2) which allow a medium to flow through them in series. The filter corrugations (1, 2) adjoin one another in an interface region (S) between the outflow surface (12) of the first filter corrugation (1) and the inflow surface (21) of the second filter corrugation (2). A surrounding seal (3) is located in the interface region (S), said seal integrally connecting the two filter bellows (1, 2) to each other. One of the filter corrugations (1, 2) has a smaller extent in at least one direction transverse to the flow direction (D) than the other filter corrugations (1, 2), the filter corrugations (1, 2) being arranged relative to one another in the at least one direction transverse to the flow direction (D) such that, in an interface region (S), the filter corrugations (1, 2) extend along the larger filter corrugations (1, 2). At least one edge of the larger filter bellows (1, 2) has a free space (F) on the inflow surface (11, 21) or the outflow surface (12, 22) of the larger filter bellows (1, 2). The surrounding seal (3) is integrally connected directly to the larger filter bellows (1, 2) in the region of the free space (F). A filter device (100) having a filter element (10) according to the invention is also disclosed.

Description

Technical Field

[0001] The invention relates to a filter element for an air filter system, in particular an air filter element, in particular an air intake filter system for a cabin air filter system or a fuel cell, and also to a filter device having such a filter element. Background Art

[0002] A filter element or filter insert is generally understood to be in the form of an insert which is replaceably arranged as a unit in a filter housing and comprises at least a filter medium body of a filter medium, which is generally in the form of pleated filter bellows, and generally also a structure that supports or carries the filter medium, and generally also a seal. The corresponding filter medium generally has a limited service life. Therefore, the filter element must be replaced regularly as a unit.

[0003] Nowadays, the air flowing into the vehicle cabin is as free of pollutants as possible. Pollutants that may occur are, for example, particulate matter, pollen, soot or aerosols. Particularly in applications where high concentrations of plant protection agents or liquid fertilizers are present in the ambient air, it is important to filter such pollutants when using spray devices for these substances. Various filtering means can be used for this purpose. For example, particle filters, activated carbon filters and HEPA filters are often used. These are combined in various layers and in various arrangements in order to achieve an ideal filtering effect for the interior air.

[0004] Since in practice combinations of very different polluting substances to be separated occur, the use of multi-stage filter systems or filter elements has already been established.

[0005] Prior art

[0006] EP 3520878 A1 discloses a filter module for filtering internal air with three filter layers, wherein the filter layers are arranged in a common frame assembled from extruded profile strips. One of the filter layers includes an adsorption filter formed as a honeycomb body, and the other two filter layers include particle filters. The particle filter layer includes a separate filter corrugated member that can be flowed through in series, wherein one of the filter corrugated members includes a HEPA filter medium. The profile strip of the frame holds a plurality of filter layers inwardly; outwardly, the filter module is tightly sealed in the housing by means of the frame. In addition, the filter module includes a circumferentially extending sealing flange, which is formed at the profile strip and protrudes radially outward in the region of two particle filter elements. The profile strip also includes two circumferentially extending collar sections, which protrude inwardly, and the two filter layers are supported at the collar sections respectively. This structure, combined with the configuration of the particle filter layer as a separate filter corrugated member, requires a relatively large installation space in the axial direction.

[0007] The disadvantages in this regard are the relatively complex configuration and the high material input and the manufacturing costs associated therewith. In addition, due to the mixing of the materials used, there are disposal problems, since pure heat recovery is not possible.

[0008] In addition, WO 2015 / 092681 A1 discloses a filter element having two filter bellows, through which a flow can flow in series and both of which include a cellulose-based filter medium. The two filter bellows are adjacent to each other in an adjoining area and are held at a predetermined distance in the flow direction by a spacer. The two filter bellows have the same dimensions transversely to the flow direction and are connected by a common circumferentially extending seal made of PUR material, which is connected to the sides of the two filter bellows in the adjoining area. A disadvantage in this regard is that the connection of the two filter bellows is not load-resistant enough, which can cause problems in particular in the event of vibrations during operation.

[0009] It is therefore desirable to provide a filter element which integrates a plurality of filter stages and which is at the same time more resistant to mechanical loads than known multi-stage filter elements. Summary of the invention

[0010] In view of this background, the present invention has the object of providing an improved filter element.

[0011] This object is achieved by a filter element having the features of claim 1 and a filter device having the features of claim 17. Further embodiments of the invention are subject matter of the dependent claims and of the embodiments of the invention described below.

[0012] The filter element according to the present invention is particularly an air filter element for an air filter system, particularly an air intake filter system for a cabin air filter system or a fuel cell. The filter element comprises two filter corrugated members, which are arranged adjacent to each other in a predetermined flow direction so that they can be flowed through in series. Each filter corrugated member comprises an inflow surface and an outflow surface and at least four sides. The filter corrugated members are adjacent to each other in the interface region between the outflow surface of the first filter corrugated member and the inflow surface of the second filter corrugated member. In the interface region, there is a circumferentially extending seal, which directly connects the two filter corrugated members to each other by material fusion. One of the filter corrugated members includes an extension smaller than the other filter corrugated member in at least one direction transverse to the flow direction, wherein the filter corrugated members are arranged relative to each other in at least one direction transverse to the flow direction so that in the interface region, along at least one edge of the larger filter corrugated member, there is a free space not covered by the smaller filter corrugated member at the inflow surface or outflow surface of the larger filter corrugated member. The circumferentially extending seal is connected in the region of the free space directly to the inflow surface or outflow surface of the larger filter bellows by material fusion.

[0013] Thus, in the filter element according to the invention, the mechanical load resistance of the connection of the two filter bellows is significantly increased. This is achieved in particular by the enlarged contact surface of the circumferentially extending seal, which is formed integrally by material fusion at the filter bellows. In addition, the integration of the circumferentially extending seal at the inflow surface or outflow surface of the larger filter bellows further increases the rigidity of the entire filter element, which improves its handling particularly during maintenance.

[0014] The term "free space" refers to the virtual area left due to the smaller size of one filter element relative to the other filter element in the interface area at the inflow surface or outflow surface of the larger filter element. However, in the finished filter element, the circumferentially extending seal is installed in this virtual free space, so that this area does not remain free, but is to be understood as an auxiliary means for describing the structural configuration of the filter element.

[0015] Advantageously, the filter element according to the invention can consist completely of heat-recyclable material, so that no disposal problems arise and in particular no disassembly of individual components of the filter element is required during recycling.

[0016] In an embodiment, the filter bellows and / or the filter element itself are each implemented in a rectangular parallelepiped shape. The rectangular parallelepiped component can be assembled to the filter element inexpensively and achieves efficient use of the installation space.

[0017] Furthermore, in particular in the case of cuboid outer dimensions, a symmetry can be achieved with respect to a certain plane through the filter element, which enables a beneficial mass distribution of the filter element.

[0018] In this context, one speaks of the axial direction and the radial direction of the filter element, wherein "axial" means in the direction of flow, i.e. perpendicular to the inflow surface or side of the filter element, which is, for example, cuboid in shape. The term "radial" particularly means the direction of the normal to the side or side wall of the frame or, in particular, the side surface of a cuboid filter element.

[0019] The corresponding filter corrugated element can comprise a filter medium, which is for example a filter fabric, a paved filter material or a filter nonwoven. In particular, the filter medium can be produced by a spunbond process or a meltblown process. In addition, the filter medium can be felted or needle-punched. The filter medium can comprise natural fibers, such as cotton, or synthetic fibers, for example synthetic fibers of polyester, polyphenylene sulfide or polytetrafluoroethylene.

[0020] In order to form a corresponding filter corrugation, the filter medium is folded or wrinkled a number of times. The fold distance of the filter corrugation can be, for example, between 3 and 5 mm, and the fold height between 20 and 30 mm. In an embodiment, there can be 30 to 300 folds.

[0021] In this case, the filter element according to the invention is suitable as a replaceable component of an air filter system, in particular for a cabin air filter system or an intake air filter system of a fuel cell, and can be installed in particular in a filter housing fixed in the vehicle.

[0022] In an embodiment, the circumferentially extending seal can be additionally directly connected to at least one side of the two filter bellows by material fusion at at least one edge of the larger filter bellows. This further improves the load resistance of the connection of the two filter elements and increases the final rigidity of the filter element as a whole, in particular with respect to axial force loads and / or bending around an axis transverse to the flow direction.

[0023] In an embodiment, the circumferentially extending seal may comprise or consist of a plastic material, in particular a foamed polyurethane or a thermoplastic elastomer. The aforementioned material can be provided in a liquid or pasty initial state very well and can be formed directly into one piece to the two filter bellows by material fusion in the manner according to the invention with the aid of a casting mold. In the casting mold, the raw material provided in a liquid or pasty initial state solidifies and subsequently forms the final material of the circumferentially extending seal.

[0024] According to another embodiment, the cross section of the circumferentially extending seal may include at least three legs, namely

[0025] - transverse legs connected to the inflow surface or outflow surface of the larger filter bellows, and

[0026] - a first longitudinal leg connected to the side of the smaller filter bellows, and

[0027] - A second longitudinal leg connected to the side of the larger filter bellows.

[0028] Advantageously, all three legs of the circumferentially extending seal can be produced in a single tool (casting mold) in a common method step. In other words, the aforementioned legs - transverse legs, first longitudinal legs and second longitudinal legs - can also be referred to as connecting legs of the circumferentially extending seal, because they are primarily used to connect two filter bellows.

[0029] In addition, the circumferentially extending seal can include a radially protruding circumferentially extending sealing area, which is formed so as to tightly contact the housing sealing surface of the filter housing. The sealing area suitable for the technical boundary conditions of the filter housing can include various cross-sections that seem suitable to those skilled in the art. Therefore, the sealing area can be configured for a radially or axially acting sealing effect, and can alternatively or additionally include one or more sealing lips or sealing grooves. Advantageously, the sealing area can be produced by casting together with the connecting legs of the circumferentially extending seal in a common method step.

[0030] In an embodiment, each filter bellows may have exactly four sides, in particular in the case of a cuboid shape. However, other basic shapes of the filter bellows are also possible, in particular certain polygons, in particular polygons with more than five corners.

[0031] According to a further embodiment, in at least one direction transverse to the flow direction, the smaller filter corrugated element may include a smaller extension than the other filter corrugated elements, wherein the filter corrugated elements are arranged relative to each other in at least one other direction transverse to the flow direction in such a way that in the interface area along at least one other edge of the larger filter corrugated element, there is a free space not covered by the smaller filter corrugated element at the inflow surface or the outflow surface of the larger filter corrugated element, wherein a circumferentially extending seal is directly connected to the inflow surface or the outflow surface of the larger filter corrugated element by material fusion in the area of ​​the free space.

[0032] In an embodiment, it is possible that at the inflow surface or outflow surface of the larger filter corrugated element, free space is left at at least one pair of oppositely positioned edges, respectively. In other words, in this case, the smaller filter corrugated element can be arranged so as to be displaced in two different directions, extending transversely to the flow direction, respectively extending a predetermined amount from a pair of oppositely positioned edges of the larger filter corrugated element. The connection of the circumferentially extending seal to the inflow surface or outflow surface of the larger filter corrugated element in the region of the free space can in this case be implemented to extend completely around the circumferential portion.

[0033] In addition, at least one of the filter bellows may include at least one particle filter medium, in particular a synthetic nonwoven material and / or a cellulose-based filter medium, wherein the particle filter medium particularly meets the filter grade H13 or H14 according to DIN EN1822-1. As an alternative or in addition, at least one of the filter bellows may include at least one gas filter medium, in particular at least one adsorber, in particular activated carbon, zeolite and / or ion exchanger. The gas filter medium may also include its own particle filter layer, in particular a specific synthetic nonwoven material. Alternatively, the gas filter medium may also only contain a carrier layer to which the adsorber is fixed, the carrier layer being provided in a granular or particulate form, wherein the carrier layer may have a nonwoven material having a significantly larger pore size than the particle filter medium.

[0034] According to a further preferred embodiment, the smaller filter bellows can comprise a gas filter medium. On the one hand, this has the advantage that in the filter bellows with the particle filter medium, a larger filter surface can be obtained, which is advantageous in particular in the case of high-separation particle filter media in the HEPA range. On the other hand, a further advantage is that, due to the circumferentially extending seal, the edge of the smaller filter bellows facing the larger filter bellows is completely surrounded, so that adsorber, in particular activated carbon particles, can be effectively prevented from escaping to the outside. If adsorber particles break away from the gas filter medium during operation, they do not reach the environment, but are essentially captured in the interface region.

[0035] In particular, the filter bellows comprising the particle filter medium can be arranged upstream of the filter bellows comprising the gas filter medium. In this way, the air flow through the filter element according to the invention can first flow through the filter bellows comprising the particle filter medium and then through the filter bellows comprising the gas filter medium. This has the advantage that the gas filter medium can be flowed through by air without particles, which improves the adsorption properties of the gas filter medium, in particular with regard to time, because the pores of the adsorber of the gas filter medium are not "blocked" by particles.

[0036] Obviously independently of the above, it can be provided that the smaller filter bellows are arranged upstream and the larger filter bellows are arranged downstream.

[0037] Furthermore, the particle filter medium and / or the gas filter medium can comprise an antimicrobial and / or antiallergic effect. Antimicrobial substances such as zinc pyrithione or nanosilver, and antiallergic substances such as polyphenols are conceivable.

[0038] According to a further embodiment, it can be provided that the smaller filter bellows comprises a frame element extending at least partially circumferentially, in particular comprising at least one side band attached to the end face edge of the fold of the filter bellows and / or at least one head band attached to the end fold of the filter bellows. The side bands and / or the head band can comprise or consist of a synthetic nonwoven material. The side bands are in particular tightly sealedly glued to the fold profile, and the head band also forms a tightly sealed closure relative to the folded filter medium.

[0039] According to a further embodiment, the circumferentially extending seal can be directly connected to the at least partially circumferentially extending frame element of the smaller filter bellows by material fusion. This even further improves the mechanical load resistance of the connection of the two filter bellows and additionally has a favorable effect on the overall stiffness of the filter bellows. Furthermore, in embodiments in which the smaller filter bellows comprises a gas filter medium, a reduced escape tendency of adsorber particles present in the gas filter medium can be achieved by "framing" the smaller filter bellows by the frame element.

[0040] Independently of this embodiment, the direct material fusion connection of the circumferentially extending seal may be a foam-molded connection, which is an established process in industry, in particular when polyurethane is used as starting material.

[0041] As an alternative or in addition, the larger filter bellows can include sealed fold end face edges, in particular in the form of a fluid-tight adhesive connection of the fold gap and / or at least one frame element attached to the fold end face edges. Due to the sealed end face edges, filter medium bypassing the larger filter bellows is avoided.

[0042] Furthermore, a spacer element can be present in the interface region, which spacer element predetermines the distance of the two filter bellows relative to each other in the flow direction. The spacer element can extend in particular with at least one part transversely to the fold length extension of at least one filter bellows, so as to achieve optimal support at as many contact points as possible. In order to achieve a uniform flow through the two filter bellows, a distance between the two filter bellows is in principle advantageous. However, the spacer element not only serves to support the two filter elements relative to each other, but also achieves a stabilizing function for the filter element as a whole.

[0043] The spacer element can comprise adhesive tracks applied to the ends of a plurality of folds of at least one filter corrugation, at least one wire glued to the ends of the folds and / or a grid arranged in the interface region. The grid can consist of a plastic material and in particular be provided as an injection-molded part: in this way, a particularly good reinforcement of the spacer element can be achieved.

[0044] In an embodiment, the mesh may comprise an at least partially circumferentially extending collar section which radially protrudes beyond the larger filter corrugations. Preferably, however, the collar section of the mesh extends completely circumferentially. The collar section of the mesh may in particular be embedded in the material of the circumferentially extending seal, preferably by foaming. In particular, the collar section of the mesh may be completely surrounded by the material of the circumferentially extending seal.

[0045] The collar section of the mesh can in particular extend at least partially in the plane in which the interface area lies. However, in embodiments, the collar section of the mesh can also be at least partially angled relative to the plane of the interface area, in particular in order to reinforce the sealing area of ​​the circumferentially extending seal internally. In embodiments, the collar section of the mesh can be angled in the direction towards the larger filter bellows.

[0046] In particular, the collar segment is produced integrally with the mesh material and can be produced together with the mesh in a common process step.

[0047] Furthermore, seen in the radial direction, at least one section of the mesh can extend from the at least partially circumferentially extending protruding edge beyond the collar section and beyond the circumferentially extending seal. Preferably, however, the protruding edge extends completely circumferentially. The protruding edge is in particular produced integrally with the material of the mesh and / or the collar section and can be produced together with the mesh and / or the collar section in a common process step.

[0048] The collar section and / or the protruding rim preferably consists of a harder material than the circumferentially extending seal, in particular a plastic material, in particular an injection-mouldable plastic material.

[0049] On the one hand, the protruding edge additionally strengthens the filter element; on the other hand, at least one fastening device can be formed there, by means of which the filter element can be held in the filter housing. The fastening device can be, for example, a protrusion, which includes at least one fastening element, such as a through hole or a snap element for tightening.

[0050] The filter corrugations may include different fold distances, wherein the fold distances of smaller filter corrugations are greater than the fold distances of larger filter corrugations. In other words, the fold distances in filter corrugations including gas filter media may be greater than the fold distances in filter corrugations including particle filter media.

[0051] Another aspect of the invention relates to a filter device, in particular a filter device for a cabin air filter system or an air intake filter system for a fuel cell. The filter device comprises a filter housing having two housing parts, wherein at least one housing part comprises a filter element receptacle, in which a filter element according to the invention is arranged. The filter housing comprises at least one circumferentially extending housing sealing surface, on which a circumferentially extending seal of the filter element rests in a tightly sealing manner.

[0052] In an embodiment, it can be provided that the circumferentially extending seal is axially compressed between the two housing parts when the filter element is arranged as intended in the filter housing.

[0053] Other possible embodiments of the present invention also include combinations of features not explicitly mentioned previously or below with respect to the embodiment description. In this case, those skilled in the art will also add separate aspects as improvements or supplements to the corresponding basic forms of the present invention. Hereinafter, the present invention will be explained in more detail by means of embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In this case, the following is shown:

[0055] Figure 1 is a perspective view of a filter element according to the present invention;

[0056] Figure 2 is a plan view of a filter element according to the present invention;

[0057] Figure 3 according to Figure 2 Section AA;

[0058] Figure 4 is a side view of a filter element according to the present invention, with a cut-away portion;

[0059] Figure 5 according to Figure 4 Details of Z;

[0060] Figure 6 is a longitudinal cross-sectional view of a filter device according to the present invention;

[0061] Figure 7 is a cross-sectional view of a filter element according to the present invention according to another embodiment;

[0062] Figure 8 is a cross-sectional view of a filter element according to the present invention according to a further embodiment. DETAILED DESCRIPTION

[0063] Figure 1 The filter element 10 according to the invention is shown in a perspective view. The filter element 10 comprises two filter corrugated members 1, 2, each of which has a filter medium arranged in folds 15, 25, wherein the filter corrugated members 1, 2 are arranged adjacent to each other in the direction of a predetermined flow direction D so that a flow can flow through them in series. The filter corrugated members 1, 2 each have an inflow surface 11, 21 and an outflow surface 12, 22 (see Figure 3 ) and four side surfaces 13, 14, 23, 24. At the longitudinal ends of the folds 15, 25, the folded filter media of the filter bellows 1, 2 respectively include fold end surface edges 15', 25' (see Figure 4 ). The first filter corrugated element 1 is arranged upstream of the second filter corrugated element 2. The first filter corrugated element 1 particularly comprises a filter medium for gas filtration, particularly with activated carbon as an adsorber; the second filter corrugated element 2 particularly exclusively comprises a particle filter medium.

[0064] The folded filter medium of the first filter bellows 1 has an edge 15' (see FIG. Figure 4 ) are provided with side bands 131 respectively, and head bands 141 are provided at the end folds thereof. The side bands 131 and head bands 141 represent circumferentially extending frame elements that frame the pleated filter medium 15 of the first filter bellows 1.

[0065] The basic shape of the filter element 10 and the filter bellows 1 , 2 as a whole is a cuboid, in which there are distinct long sides and distinct short sides.

[0066] The filter element 10 further comprises a circumferentially extending sealing member 3 which connects the two filter bellows 1 , 2 and is directly formed integrally therewith by material fusion, in particular foaming.

[0067] The second filter bellows 2 comprises a sealed fold end edge 25' which is realized in the form of a fluid-tight adhesive connection of the fold recess 251 (see Figure 4 As an alternative, a frame element applied to the fold end face edge 25' of the filter medium of the second filter bellows 2 can be provided for sealing the fold end face edge.

[0068] The first filter corrugated member 1 is smaller than the second filter corrugated member 2 , wherein “smaller” refers to a dimension transverse to the flow direction D.

[0069] Figure 2The filter element 10 according to the invention is shown in a plan view, wherein the first filter bellows 1 is positioned at the top.

[0070] Figure 3 Shown along Figure 2 The cross section shown is a section plane AA, which extends parallel to the short sides 14, 24 of the filter element 10. Figure 3 In the figure, the internal configuration of the filter element 10 can be seen, in particular the connection of the two filter corrugations 1, 2 by means of a circumferentially extending seal 3. The filter corrugations 1, 2 abut against each other in the interface region S between the outflow surface 12 of the first filter corrugation 1 and the inflow surface 21 of the second filter corrugation 2. The filter corrugations 1, 2 are held at a predetermined distance relative to each other in the flow direction D by means of a spacer element 26. The spacer element 26 extends transversely to the fold length extension of at least one of the filter corrugations 1, 2. The spacer element 26 is in particular an adhesive track applied to a plurality of fold ends 27 of the second filter corrugation 2, or a line glued to the fold ends 27.

[0071] Since the first filter corrugated element 1 is smaller than the second filter corrugated element 2, at the oppositely positioned edges of the larger filter corrugated element 2, a free space F remains in the interface region S at its inflow surface 21, which free space F is not covered by the first filter corrugated element 1. The smaller first filter corrugated element 1 is arranged to be displaced in such a way that there is a free space F at the oppositely positioned edges of the larger second filter corrugated element 2, wherein in particular the respective free spaces F at the oppositely positioned edges of the larger second filter corrugated element 2 have the same size.

[0072] In the region of the free space F, the circumferentially extending seal 3 is directly connected to the inflow surface 21 of the larger filter corrugated element 2 by material fusion. Furthermore, the circumferentially extending seal 3 is directly connected to the side surfaces 13, 14 of the first smaller filter corrugated element 1 by material fusion (see Figure 4 ) and the sides 23, 24 of the second larger filter corrugated element 2 (see Figure 4 ).

[0073] The two filter bellows 1 , 2 are therefore connected to one another via the circumferentially extending seal 3 .

[0074] Since the connection is realized via the respective side faces 13, 14, 23, 24 of the two filter corrugations 1, 2 and via the inflow surface 21 of the second filter corrugated member 2, the contact surface of the circumferentially extending seal 3 relative to the filter corrugated members 1, 2 is maximized, which contributes to a mechanically very load-resistant connection. The connection via the respective side faces 13, 14, 23, 24 of the two filter corrugated members 1, 2 and via the inflow surface 21 of the second filter corrugated member 2 preferably extends completely circumferentially.

[0075] In the radially projecting region of the circumferentially extending seal 3 , there is a sealing region 31 which, in the installed state of the filter element 10 , contacts at least one sealing surface arranged on the housing.

[0076] exist Figure 4 , the filter element 10 is shown in a side view in the projection direction along the short side faces 14 , 24 , and in particular the connection of the spacer element 26 to the fold end 27 of the second filter corrugated element 2 can be seen.

[0077] Will be aided by Figure 5 The details Z shown are explained in more detail.

[0078] Thus, the circumferentially extending seal 3 comprises a first longitudinal leg 33 connected to the side 14 of the first filter corrugated element 1. More precisely, the first longitudinal leg 33 is connected to a headband 141 which is present at the side 14 and at the end fold of the folded filter medium of the first filter corrugated element 1. Furthermore, the circumferentially extending seal 3 comprises a second longitudinal leg 34 which is connected to the side 24 of the second filter corrugated element 2. More precisely, the second longitudinal leg 34 is connected to the end fold of the filter medium of the second filter corrugated element 2. Finally, the circumferentially extending seal 3 further comprises a transverse leg 32 which is connected to the inflow surface 21 of the second filter corrugated element 2. Furthermore, the transverse leg 32 is advantageously connected to the adjacent surface of the headband 141 of the first filter corrugated element 1. Similarly, the transverse leg 32 can also advantageously be connected to the adjacent surface of the side band 131 of the first filter corrugated element 1, which is advantageous in Figure 3 . The term "adjoining surface" means an axially oriented covering surface. Due to the connection of the circumferentially extending seal 3 with the different contact surfaces of the two filter corrugated members 1, 2 explained above and the T-shape generated by the longitudinal legs 33, 34 and the transverse legs 32 in the connection area of ​​the two filter corrugated members 1, 2, the rigidity of the entire filter element 10 is advantageously significantly increased. By the arrangement of the spacer element 26 in the interface area S, the rigidity is further enhanced, in particular with respect to the rigidity of the bending around the axis transverse to the flow direction D.

[0079] Figure 6 Finally, the filter element 10 according to the invention is shown installed in the filter housing 4 of an air filter system 100, in particular a cabin air filter system or an intake air filter system of a fuel cell. The filter housing 4 comprises two housing parts 41, 42, which together define a filter element receptacle. The lower housing part 41 can be a housing disc, and the upper housing part 42 can be a housing cover.

[0080] The first housing part 41 as well as the second housing part 42 each provide a circumferentially extending sealing surface 411, 421, at which the sealing area 31 of the circumferentially extending seal 3 of the filter element 10 rests tightly and sealingly. In this case, the sealing area 31 of the circumferentially extending seal 3 is tightly and sealingly clamped axially between the housing parts 41, 42 by means of corresponding axial contact surfaces, facing the sealing surface 411 of the first housing part 41 and the sealing surface 421 of the second housing part 42. In order to improve the force transmission to the sealing area 3 of the circumferentially extending seal 3, at least one of the housing parts 41, 42 comprises a circumferentially extending rib, which pushes the corresponding axially oriented contact surface of the sealing area 31.

[0081] Figure 7 A filter element 10 according to the invention is shown in longitudinal section according to a further embodiment. The filter element 10 corresponds substantially to Figures 1 to 5 The filter element 10 shown in FIG. 1 is configured so that the filter element 10 and Figure 6 The features, feature combinations and their specific technical advantages described for the filter device 100 of FIG. 1 are applicable. In the following, only the differences will be explained.

[0082] The spacer element 26 comprises a grid 26" present in the interface region S between the two filter corrugations 1, 2. The grid 26" is fluid-permeable and comprises in particular a plurality of grid openings, between which grid webs extend, the grid webs contacting the respective fold ends of the filter corrugations 1, 2 facing the interface region S so as to space the filter corrugations 1, 2 apart by a predetermined distance. The grid 26" has a circumferentially extending collar section 261 which protrudes radially beyond the larger filter corrugation 2. The collar section 261 of the grid 26" is embedded in the material of the circumferentially extending seal 3, in particular by foaming. In particular, the collar section 261 of the grid 26" is completely surrounded by the material of the circumferentially extending seal 3, i.e. on all sides.

[0083] The collar segment 261 of the grid 26" extends in a plane in which the interface area S is positioned in a first section. In a second section, the collar segment 261 is angled relative to the plane of the interface area S so as to internally reinforce the sealing area 31 of the circumferentially extending seal 3. According to this embodiment, the collar segment 261 of the grid 26" is angled in a direction toward the larger filter corrugated member 2. The angled second section may include a bend, curve or fold.

[0084] The collar section 261 is produced integrally with the material of the grid 26 ″ and is produced in particular with the grid 26 ″ by a common process step.

[0085] When producing the filter element 10, the grid 26" is first provided together with the collar section 261 formed thereon, and then the two filter corrugated members 1, 2 are arranged thereon. In a subsequent step, the two filter corrugated members 1, 2 are connected by foaming or casting the circumferentially extending seal 3, thereby also forming the seal section 31 and embedding the collar section 261 in the material of the circumferentially extending seal 3. The foaming or casting can be achieved by means of a foaming or casting mold, which includes the negative contour of the circumferentially extending seal 3.

[0086] In addition, viewed in the radial direction, at least one section of the grid 26" may extend beyond the collar section 261 and beyond the circumferentially extending seal 3, forming an at least partially circumferentially extending protruding edge 262, which in accordance with Figure 8 . The protruding edge 262 is not surrounded by the material of the circumferentially extending seal 3 and is in particular exposed. In particular, the protruding edge 262 extends completely circumferentially along the circumferentially extending seal 3. The protruding edge 262 is produced integrally with the material of the grid 26" and the collar segment 261 and can be produced together with the grid 26" and the collar segment 261 in a common process step. The protruding edge 262 is in particular embodied as a collar and is angled relative to the plane of the interface area S. The protruding edge 262 is in particular angled in a direction oriented opposite to the angled second segment of the collar segment 261.

[0087] The protruding edge 262 strengthens the filter element 10 on the one hand; on the other hand, a fastening device can be integrally formed at the protruding edge 262, by means of which the filter element 10 can be held in the filter housing. The fastening device can be, for example, a protrusion comprising at least one fastening element, such as a through hole or a snap element for tightening; however, this is not illustrated in the drawings.

[0088] Reference numerals used

[0089] 100 Filters

[0090] 10 Filter element

[0091] 1. First filter bellows

[0092] 11 Inflow surface of the first filter corrugated element

[0093] 12 Outflow surface of the first filter corrugated element

[0094] 13, 14 Side of the first filter corrugated element

[0095] 131 Side band of the first filter corrugated element

[0096] 141 Headband of the first filter bellows

[0097] 15 Folded portion of the first filter corrugated element

[0098] 15' The folded end face edge of the first filter corrugated element

[0099] 2 Second filter bellows

[0100] 21 Inflow side of the second filter bellows

[0101] 22 Outflow side of the second filter bellows

[0102] 23, 24 Side of the second filter corrugated element

[0103] 25 Folded portion of the second filter corrugated element

[0104] 25' The folded end face edge of the second filter corrugated element

[0105] 251 The gap of the folded portion of the second filter corrugated element

[0106] 26 Spacer element

[0107] 26' Adhesive Track

[0108] 26" Grid

[0109] 261 Loop segment of the grid

[0110] 262 The protruding edge of the mesh collar

[0111] 27 The end of the folded portion of the second filter corrugated element

[0112] 3 Circumferentially extending seal

[0113] 31 Sealed area

[0114] 32 Horizontal outriggers

[0115] 33 First longitudinal leg

[0116] 34 Second longitudinal leg

[0117] D Flow direction

[0118] F Free Space

[0119] S Interface area

[0120] 4 Filter housing

[0121] 41 first housing part

[0122] 411 Circumferentially extending sealing surface of the first housing portion

[0123] 42 Second housing part

[0124] 421 Circumferentially extending sealing surface of the second housing portion

Claims

1. A filter element (10), in particular an air filter element, for use in an air filter system, in particular a cabin air filter system or an air intake filter system for a fuel cell, - comprises two filter bellows (1, 2) which are arranged adjacent to each other in the direction of a predetermined flow direction (D) in such a way that a flow can flow through them in series, -in, Each of the filter bellows (1, 2) comprises an inflow surface (11, 21), an outflow surface (12, 22) and at least four side surfaces (13, 14, 23, 24), - wherein the filter corrugated elements (1, 2) abut against each other in an interface region (S) between an outflow surface (12) of the first filter corrugated element (1) and an inflow surface (21) of the second filter corrugated element (2), - also comprising a circumferentially extending seal (3) present in the interface region (S) which directly connects the two filter bellows (1, 2) to one another by material fusion, Features One of the filter corrugated elements (1, 2) comprises a smaller extension than the other filter corrugated element (1, 2) in at least one direction transverse to the flow direction (D), wherein the filter corrugated elements (1, 2) are arranged relative to each other in at least one direction transverse to the flow direction (D) in such a way that in an interface region (S), along at least one edge of the larger filter corrugated element (1, 2), there is a free space (F) not covered by the smaller filter corrugated element (1, 2) at the inflow surface (11, 21) or the outflow surface (12, 22) of the larger filter corrugated element (1, 2), wherein the circumferentially extending seal (3) is directly connected to the inflow surface (11, 21) or the outflow surface (12, 22) of the larger filter corrugated element (1, 2) in the region of the free space (F) by material fusion.

2. The filter element (10) according to claim 1, wherein A circumferentially extending seal (3) is additionally directly connected to at least one side surface (13, 14, 23, 24) of the two filter corrugations (1, 2) at the at least one edge of the larger filter corrugated element (1, 2) by material fusion.

3. The filter element (10) according to claim 1 or 2, wherein: The circumferentially extending seal (3) comprises or consists of a plastic material, in particular foamed polyurethane or a thermoplastic elastomer.

4. The filter element (10) according to any one of the preceding claims, wherein The circumferentially extending seal (3) comprises at least three legs (32, 33, 34) in cross section, - a transverse leg (32) connected to the inflow surface (11, 21) or the outflow surface (12, 22) of the larger filter bellows (1, 2), and - a first longitudinal leg (33) connected to the side (13, 14, 23, 24) of said smaller filtering corrugated element (1, 2), and - A second longitudinal leg (34) connected to the side (13, 14, 23, 24) of said larger filtering corrugated element (1, 2).

5. The filter element (10) according to any one of the preceding claims, wherein The circumferentially extending seal (3) comprises a radially protruding circumferentially extending sealing area (31), wherein the sealing area (31) is configured to tightly sealably contact a housing sealing surface (411, 421) of a filter housing (4).

6. The filter element (10) according to any one of the preceding claims, wherein The filter bellows (1, 2) each comprise precisely four side faces (13, 14, 23, 24) and / or comprise a cuboid basic shape.

7. The filter element (10) according to any one of the preceding claims, wherein The smaller filter corrugated element (1, 2) comprises a smaller extension than the other filter corrugated elements (1, 2) in at least one other direction transverse to the flow direction (D), wherein the filter corrugated elements (1, 2) are arranged relative to each other in at least one other direction transverse to the flow direction (D) so that in the interface region (S), along at least one other edge of the larger filter corrugated element (1, 2), there is a free space (F) not covered by the smaller filter corrugated element (1, 2) at the inflow surface (11, 21) or the outflow surface (12, 22) of the larger filter corrugated element (1, 2), wherein the circumferentially extending seal (3) is directly connected to the inflow surface (11, 21) or the outflow surface (12, 22) of the larger filter corrugated element (1, 2) in the region of the free space (F) by material fusion.

8. The filter element (10) according to any one of the preceding claims, wherein - at least one of the filter bellows (1, 2) comprises at least one particle filter medium, in particular a synthetic nonwoven material and / or a cellulose-based filter medium, wherein in particular the particle filter medium satisfies filter class H13 or H14 according to DIN EN 1822-1, and / or At least one of the filter bellows (1, 2) comprises at least one gas filter medium, in particular at least one adsorber, in particular activated carbon, zeolite and / or ion exchanger.

9. The filter element (10) according to claim 8, wherein The smaller filter bellows (1, 2) include a gas filter medium.

10. The filter element (10) according to any one of the preceding claims, wherein The smaller filter bellows (1, 2) comprises a frame element (131, 141) extending at least partially circumferentially, in particular comprising at least one side band (131) applied to the end face edge (15', 25') of the folded portion of the filter bellows (1, 2) and / or at least one head band (141) applied to the end fold of the filter bellows, wherein in particular the side band and / or the head band (131, 141) comprise a synthetic non-woven material or consist of a synthetic non-woven material.

11. The filter element (10) according to claim 10, wherein: The circumferentially extending sealing element (3) is directly connected to at least partially circumferentially extending frame elements (131, 141) of the smaller filter bellows (1, 2) by material fusion.

12. The filter element (10) according to any one of the preceding claims, wherein The direct material fusion connection of the circumferentially extending seal (3) is a foamed connection.

13. The filter element (10) according to any one of the preceding claims, wherein The larger filter bellows (1, 2) comprises a sealed fold end edge (15', 25'), in particular a fluid-tight adhesive connection of the fold gap (251) and / or at least one frame element applied to the fold end edge (15', 25').

14. The filter element (10) according to any one of the preceding claims, wherein In the interface region (S) there is a spacer element (26, 26', 26") which predetermines the distance of the two filter bellows (1, 2) relative to each other in the flow direction (D), wherein the spacer element (26, 26', 26") extends, in particular with at least one part, transversely to the extension of the fold length of at least one of the filter bellows (1, 2).

15. The filter element (10) according to claim 14, wherein The spacer element (26, 26', 26") comprises adhesive tracks (26') applied to the ends of a plurality of folds of at least one of the filter corrugations (1, 2), at least one wire glued to the ends of the folds and / or a grid (26") arranged in the interface area (S).

16. The filter element (10) according to any one of the preceding claims, wherein The filter bellows (1, 2) comprise different fold distances, wherein in particular the fold distance of the smaller filter bellows (1, 2) is greater than the fold distance of the larger filter bellows (1, 2).

17. A filter device (100), in particular a filter device for a cabin air filter system or an air intake filter system of a fuel cell, comprising a filter housing (4) having two housing parts (41, 42), at least one of the housing parts comprising a filter element receptacle, in which a filter element is arranged, wherein: The filter housing (4) comprises at least one circumferentially extending housing sealing surface (411, 421), on which a circumferentially extending seal of the filter element rests tightly and sealingly, characterized in that the filter element is a filter element (10) according to any of the preceding claims.

18. The filtering device (100) according to claim 17, wherein: When the filter element (10) is arranged as intended in the filter housing (4), the circumferentially extending seal (3) is axially compressed between the two housing parts (41, 42).

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