Filter element and filter device

Abstract

The present invention relates to a filter element (1) comprising a filter bellows (10) which is arranged around a longitudinal axis (L) and which at least partially encloses an interior (11) and has a first end face (101) and a second end face (102) opposite the first end face. The filter element (1) also comprises, at the first end face, an end plate (12) which is open toward the interior (11) and on which at least one peripheral sealing contour (14) is arranged which extends in the direction of the longitudinal axis (L) from the end plate (12) that is open toward the interior (11). The outer periphery (103) and / or inner periphery (104) of the filter bellows (10) has at least one notch (105, 106). The peripheral sealing contour (14) has, in the region of the notch (105, 106) of the filter bellows (10), at least one locally limited protrusion or recess (141, 142) with respect to a radial direction (R), wherein the protrusion or recess (141, 142) of the sealing contour (14) is arranged peripherally such that its position corresponds to a peripheral position of the notch (105, 106) of the filter bellows (10).

Description

[0001] Description

[0002] Filter element and filter device

[0003] This patent application claims priority from German patent application No. DE 10 2023 129 023.1, filed with the German Patent and Trademark Office on October 23, 2023, the contents of which are hereby incorporated by reference.

[0004] Technical area

[0005] The present invention relates to a filter element for filtering a fluid, in particular an air filter element for an air filter system, in particular for an intake air filter system of a fuel cell or internal combustion engine. Furthermore, the invention relates to a filter device comprising such a filter element.

[0006] The intake air of fuel cells and / or internal combustion engines is typically cleaned of particulate and / or gaseous contaminants using an air filter before entering a cathode chamber or combustion chamber. For this purpose, air filter elements are used. Furthermore, the air flowing into a vehicle cabin is also nowadays freed of contaminants as completely as possible. Possible contaminants include particulate matter, pollen, soot, and aerosols.

[0007] A filter element or filter insert is generally understood to be a replaceable unit that can be arranged in a filter housing. It comprises at least one filter medium body made of a filter medium, often in the form of a pleated filter bellows, and usually also a structure that carries or supports the filter medium, and usually a seal. The respective filter medium typically has a limited service life, which is why filter elements must be replaced regularly.

[0008] Such filter elements or filter inserts are often designed as so-called round elements, which have a filter bellows arranged around a longitudinal axis, which at least partially encloses an interior space. The filter bellows can be defined at a first end by an open end plate and at a second end opposite the first end by another end plate, in particular a closed end plate. A circumferential seal is usually arranged on the open end plate.

[0009] For various reasons, it may be technically necessary for round filter elements to be installed in a filter housing in a predetermined installation position. For example, the above-mentioned applications often use volume and / or mass flow sensors that measure the intake air volume. Such volume and / or mass flow sensors are usually calibrated to a predetermined installation position of the round filter element, so that if the round filter element is installed in the filter housing in a position deviating from the predetermined installation position, measurement inaccuracies arise. The reason for this is that the filter media bodies usually have a seam that influences the downstream flow profile.

[0010] State of the art

[0011] WO 2019 / 219635 A1 discloses a round filter element having a circumferential filter bellows defined at each of its ends by an end plate, with at least one of the end plates being an open end plate. The filter bellows comprises a filter medium, in particular pleated in a star shape, and has, at its end near the open end plate, a spreading portion on the outer circumference, wherein the spreading portion extends only over part of the total length of the filter bellows. The spreading portion of the filter bellows is aligned with a corresponding notch on an outer circumference of the open end plate. Furthermore, a circumferential seal is arranged on the open end plate and extends radially within the notch in a circle.Furthermore, a filter housing for receiving the round filter element is disclosed therein, which has a notch in an interior space which, in an assembled state, engages in the spreading of the filter bellows of the round filter element in order to position the round filter element with regard to its angular position relative to the filter housing.

[0012] The disadvantage of this is that the sealing contour runs over a comparatively small diameter, which is detrimental to optimal sealing. Furthermore, the system proposed therein is susceptible to misuse because, for example, after the notch on the housing side has been removed, any filter element can be installed in the filter housing. Furthermore, WO 2018 / 073198 A1 discloses another filter element which has an expansion on an outer circumference of a filter bellows, wherein the filter bellows has an elongated oval cross-sectional shape. The filter bellows is delimited at each of its ends by an end plate, wherein one of the end plates is an open end plate. The filter element can be flowed through in particular from radially inward to radially outward and has a grid structure on its outer circumference which supports the filter bellows.A circumferential, radially projecting seal carrier is provided on the grid structure, which supports an axial seal. The seal carrier is spaced axially from the open end plate. The grid structure also has a radially inwardly projecting positioning element that supports the expansion and is open radially outward and axially toward the side of the open end plate, allowing a blade provided on a filter housing to engage the positioning element.

[0013] Disclosure of the invention

[0014] Against this background, the object of the present invention is to create a filter element which makes it possible to enforce a clear installation position in a filter housing and which has an improved sealing effect.

[0015] This object is achieved by a filter element having the features of claim 1 and by a filter device having the features of claim 16. Further embodiments of the invention are the subject of the subclaims and the exemplary embodiments of the invention described below.

[0016] A first aspect of the present invention relates to a filter element designed to filter a fluid and, in particular, can be an air filter element for an air filter system, in particular for an intake air filter system of a fuel cell or internal combustion engine. However, it is also fundamentally possible for the filter element according to the invention to be a liquid filter element.

[0017] According to a first embodiment, the filter element according to the invention has a filter bellows arranged around a longitudinal axis, which at least partially encloses an interior space, wherein the filter bellows has a first end and a second end opposite the first end. The filter element further has an end plate open to the interior space at the first end and a further end plate, in particular a closed end plate, at the opposite second end. At least one circumferential sealing contour is arranged on the end plate open to the interior space and rises in the direction of the longitudinal axis from the end plate open to the interior space. The filter bellows has at least one notch on its outer circumference and / or inner circumference.The circumferential sealing contour has at least one locally limited projection or recess with respect to a radial direction in the region of the notch of the filter bellows, wherein the projection or recess of the sealing contour is arranged circumferentially such that its position corresponds to a circumferential position of the notch of the filter bellows.

[0018] “First end” and “second end” herein refer in particular to ends of the filter bellows facing away from each other with respect to the longitudinal axis.

[0019] The term "filter bellows," in its broadest sense, encompasses any filter medium body that has at least one filter medium, which can be in pleated or unfolded form. The filter medium can, in particular, be a particle filter medium or a gas filter medium. Optionally, the filter medium can comprise at least one adsorbent, in particular activated carbon. A filter medium designed as a particle filter medium can, in particular, comprise a nonwoven material, in particular made of synthetic fibers and / or cellulose fibers.

[0020] The filter bellows can be flowed through in a radial direction, in particular from radially outside to radially inside, so that a clean side can be present, in particular, in the area of ​​the interior space enclosed by the filter bellows. However, in some designs, flow from radially inside to radially outside is also possible, so that a dirty side can be present in the area of ​​the interior space enclosed by the filter bellows.

[0021] The fact that the projection or recess of the sealing contour is arranged circumferentially such that its position "corresponds" to a circumferential position of the notch in the filter bellows means in particular that a positioning of the projection or recess of the sealing contour in the circumferential direction corresponds to a positioning of the notch in the filter bellows in the circumferential direction. In other words, the projection or recess of the sealing contour is arranged at a circumferential position at which the notch in the filter bellows is also present. Expressed again differently, a circumferential position of a local maximum of a deviation of the sealing contour from its basic shape in the region of the projection or recess can coincide with a circumferential position of a deepest point of the notch, viewed in the radial direction.However, minor angular deviations between the circumferential position of the sealing contour's projection or recess and the filter bellows' notch are possible, so that, for example, an alignment error of up to 20°, especially up to 15°, can still be considered a "corresponding arrangement." Such minor alignment errors are often unavoidable due to production tolerances.

[0022] The filter element according to the invention is, in particular, a round filter element. The filter bellows can, in particular, have a closed cross-section. A cross-sectional shape of the filter medium body can, for example, be selected from the group comprising circular, oval, long oval, and kidney-shaped.

[0023] The filter bellows can, in particular, have the shape of a straight or oblique prism, with its first and second ends forming the respective base and top surfaces of the prism. In particular, the filter bellows can have a hollow cylindrical shape.

[0024] The filter bellows can, in particular, completely encircle the interior, whereby the originally free circumferential ends can be connected to one another during manufacture to form a circumferentially "endless" filter bellows. However, in some embodiments, an adapter part can also be arranged between the originally free circumferential ends during manufacture, connecting the originally free circumferential ends to one another. The adapter part can, in particular, be located at a circumferential position that coincides with a circumferential position of the notch.

[0025] Alternatively or additionally, the filter bellows can also widen from the first end towards the second end or vice versa in the direction of the longitudinal axis, resulting, for example, in an overall conical shape. The filter element according to the invention is characterized on the one hand by an improved sealing effect, since the sealing contour can be guided along an optimal basic shape over a large part of the circumference and the locally limited projection or recess is only present in the area of ​​the notch of the filter bellows. On the other hand, an asymmetrical structure of the sealing contour with respect to the longitudinal axis enables an additional angular orientation of the filter element with respect to a filter housing, which functionally complements the spreading of the bellows and thus significantly reduces the possibilities of misusing the filter element in a filter housing deviating from its predetermined angular position.

[0026] In the case of a notch on the inner circumference of the filter bellows, the circumferential sealing contour has in particular a locally limited projection with respect to a radial direction, wherein the projection of the sealing contour is arranged circumferentially such that its position corresponds to a circumferential position of the notch on the inner circumference of the filter bellows.

[0027] In the case of a notch on the outer circumference of the filter bellows, the circumferential sealing contour has in particular a locally limited recess with respect to a radial direction, wherein the recess of the sealing contour is arranged circumferentially such that its position corresponds to a circumferential position of the notch on the outer circumference of the filter bellows.

[0028] According to a further embodiment, the filter bellows can have a plurality of folds, the radially outer fold edges of which lie in an outer circumferential surface and the radially inner fold edges of which lie in an inner circumferential surface. The notch can be formed by spreading at least one fold of the filter bellows on the inner and / or outer circumference.

[0029] The folds of the filter bellows can in particular be in the form of a star fold, whereby the folds can have a consistent cross-sectional shape, in particular over a large part of the circumference. The majority of folds can be V-folds with fold heights that remain constant over the circumference. Alternatively, the majority of folds can also be W-folds with intermediate folds of reduced fold height. In the region of the notch on the inner and / or outer circumference provided by the spreading, at least one fold is widened. “Widened” is understood in particular to mean that the distance between fold edges adjacent to a fold valley or a fold peak is increased compared to neighboring folds.

[0030] According to a further embodiment, the end plate open to the interior can have at least one notch corresponding to the notch of the filter bellows, which is aligned with the at least one notch.

[0031] In the case of a notch on the outer circumference of the filter bellows, the incision can be located in particular on an outer circumference of the end plate open to the interior and extend inward with a radial component. In the case of a notch on the inner circumference of the filter bellows, the incision can be located in particular on an inner circumference of the end plate open to the interior and extend outward with a radial component.

[0032] The incision penetrates a material of the opened end plate. The term "incision" serves merely as a means of describing the structure of this device component and does not imply any specific manufacturing method; in particular, the term is not to be understood as restricting it to "cutting" manufacturing.

[0033] The fact that the notch corresponding to the notch in the filter bellows is "aligned" with the at least one notch means in particular that a positioning of the notch in the circumferential direction corresponds to a positioning of the notch in the filter bellows in the circumferential direction. In other words, the notch is arranged at a circumferential position at which the notch in the filter bellows is also located. In other words, a circumferential position of a deepest point of the notch, viewed in the radial direction, can coincide with a circumferential position of a deepest point of the notch, viewed in the radial direction. However, smaller angular deviations between the circumferential position of the notch in the open end plate and the notch in the filter bellows are possible, so that, for example, an alignment error of up to 20°, in particular up to 15°, can still be referred to as a "corresponding arrangement".Such minor alignment errors are often unavoidable due to manufacturing tolerances. In some designs, the notch may be present at least at the first end of the filter bellows. This means that the notch is present at least at the end of the filter bellows where the end plate, open to the interior, is located.

[0034] In this case, it is either possible for the notch to extend in the direction of the longitudinal axis over the entire extent of the filter bellows or for the notch to be shorter in the direction of the longitudinal axis than the entire extent of the filter bellows and, in particular, to be present only in a longitudinal section of the filter bellows close to the first end.

[0035] In embodiments in which the notch is formed by a spreading of at least one fold of the filter bellows on the inner and / or outer circumference, the spreading can in particular only be present in a longitudinal section of the filter bellows close to the first end, wherein in particular in a longitudinal section of the filter bellows remote from the first end, the spreading is traced back to a regular fold shape corresponding to the majority of the folds of the filter bellows.

[0036] According to a further embodiment, the circumferential sealing contour can have a predetermined basic shape, wherein a circumferential profile of the circumferential sealing contour deviates from the predetermined basic shape in the region of the locally limited projection or recess. The predetermined basic shape can, in particular, be a circle. However, other basic shapes are also possible, such as an oval or flat oval shape. A "basic shape" is understood to mean the profile of the sealing contour in a plane of the first end of the filter bellows or in a plane of the end plate open to the interior in circumferential sections without projection or recess.

[0037] In embodiments, the end plate open to the interior can comprise or consist of a plastic material, in particular a foamed plastic material, in particular a polyurethane foam, wherein in particular the circumferential sealing contour is one piece with the end plate open to the interior. The end plate open to the interior can be connected to the first end of the filter bellows, in particular by a material bond, in particular by welding, adhesive bonding, or foam bonding. Advantageously, the circumferential sealing contour can be produced together with the end plate open to the interior in a casting process using a foamable and flowable plastic material, so that providing the projection or recess of the sealing contour does not result in any additional manufacturing effort.

[0038] According to yet another embodiment, the filter element may comprise a fluid-permeable support grid arranged on the inner circumference of the filter bellows, which in particular comprises a radial bulge which projects into a notch present on the inner circumference of the filter bellows.

[0039] The radial bulge of the support grid arranged on the inner circumference of the filter bellows serves, in particular, to support the notch present on the inner circumference of the filter bellows, to stabilize it, and / or to keep it open. The fluid-permeable support grid can comprise or consist of a plastic material, in particular an injection-moldable plastic material. The radial bulge of the support grid arranged on the inner circumference of the filter bellows can, in particular, be integral with the support grid.

[0040] According to yet another embodiment, the filter bellows can have at least two circumferentially spaced notches on its outer and / or inner circumference, wherein the circumferential sealing contour in the region of the notches of the filter bellows each has a locally limited projection or recess with respect to the radial direction. The respective projection or recess of the sealing contour is arranged circumferentially such that its position corresponds to a circumferential position of the respective notch of the filter bellows.

[0041] By providing more than one notch on the outer and / or inner circumference of the filter bellows, each combined with a locally limited projection or recess of the sealing contour, the enforcement of a predetermined installation position in a filter housing can be further improved. Furthermore, by varying the circumferential arrangement of the notches of the filter bellows and the corresponding projections or recesses of the sealing contour, it is possible to implement application-specific coding of an interface between the filter element and a filter housing.

[0042] In some embodiments, it is particularly possible to have one notch on the inner circumference and a second notch on the outer circumference of the filter bellows. The notch on the inner circumference and the notch on the outer circumference can be spaced apart, in particular, in the circumferential direction.

[0043] In the area of ​​the notch on the inner circumference of the filter bellows, the circumferential sealing contour has a locally limited projection with respect to a radial direction, wherein the projection of the sealing contour is arranged circumferentially in such a way that its position corresponds to a circumferential position of the notch on the inner circumference of the filter bellows.

[0044] In the area of ​​the notch on the outer circumference of the filter bellows, the circumferential sealing contour has a locally limited recess with respect to a radial direction, wherein the recess of the sealing contour is arranged circumferentially in such a way that its position corresponds to a circumferential position of the notch on the outer circumference of the filter bellows.

[0045] According to a further development, the end plate open to the interior can have notches corresponding to the notches of the filter bellows, each of which is aligned with one of the notches in the filter bellows. In particular, a notch on the outer circumference of the filter bellows can be assigned to a notch on the outer circumference of the open end plate, and a notch on the inner circumference of the filter bellows can be assigned to a notch on the inner circumference of the open end plate.

[0046] Finally, according to a further embodiment, the circumferential sealing contour can have at least one circumferential radial sealing surface, in particular on an inner circumference.

[0047] Alternatively, the circumferential sealing contour can have more than two radial sealing surfaces, for example a first radial sealing surface on the inner circumference and a second radial sealing surface on the outer circumference. Alternatively or additionally, it is possible for the circumferential sealing contour to have at least one axial sealing surface, in particular on an end face of the circumferential sealing contour. The sealing contour can have a predetermined sealing profile (radial section) that can comprise one or more sealing strands, in particular those running parallel to one another. However, the present invention is explicitly not limited to a specific direction of action of the seal and / or specific sealing profiles. Rather, any sealing profiles deemed suitable by a person skilled in the art can be used.

[0048] A second aspect of the present invention relates to a filter device comprising a filter housing with a fluid inlet and a fluid outlet and with a receiving space for a filter element, in which a filter element according to the first aspect of the present invention is arranged such that it separates a raw side associated with the fluid inlet from a clean side associated with the fluid outlet.

[0049] The filter device can be, in particular, an air filter device, in particular an intake air filter device of a fuel cell or internal combustion engine, or a cabin air filter device. The filter housing can be, in particular, an air filter housing.

[0050] According to a further embodiment, the filter housing can have at least one circumferential housing sealing surface against which the circumferential sealing contour of the filter element rests, wherein the housing sealing surface has at least one locally limited projection or recess which corresponds to the at least one locally limited projection or recess of the circumferential sealing contour of the filter element.

[0051] The filter housing can, in particular, be two-part and comprise a housing pot containing the receiving space, as well as a housing cover detachably connected to the housing pot. The housing sealing surface can be located either on the housing pot or on the housing cover.

[0052] The interaction between the housing sealing surface and the circumferential sealing contour of the filter element represents the main functional interface between the filter housing and the filter element. The main interface can only fulfil its main function, namely sealing the raw side from the clean side, if the housing sealing surface corresponds to the structure of the circumferential sealing contour of the filter element, whereby in particular the housing sealing surface can have the shape of a negative form of the sealing contour of the filter element, at least in sections.

[0053] Since both the housing sealing surface and the surrounding sealing contour of the filter element are not rotationally symmetrical with respect to the longitudinal axis, an interaction between the filter element and the filter housing at the main interface can reliably enforce a predetermined installation position of the filter element in the filter housing with respect to the longitudinal axis.

[0054] Alternatively or additionally, the filter housing may have at least one housing projection projecting into the receiving space, which is received in the at least one notch of the filter element.

[0055] By combining a housing sealing surface with at least one locally limited projection or recess against which the circumferential sealing contour of the filter element rests, and a housing projection which is received in the at least one notch of the filter element, the predetermined installation position of the filter element with respect to the longitudinal axis can be enforced in the best possible way, whereby misuse of the filter device is essentially excluded.

[0056] It is understood that features, combinations of features and their specific advantages disclosed with respect to the first aspect of the present invention are transferable to the second aspect of the present invention, and vice versa.

[0057] Further possible implementations of the invention also include combinations of features not explicitly mentioned above or below with regard to the exemplary embodiments. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0058] The invention will be explained in more detail below using exemplary embodiments with reference to the attached figures.

[0059] Short description of the drawings They show:

[0060] Fig. 1 is an isometric view of a filter element according to the invention according to a first embodiment;

[0061] Fig. 2 is a longitudinal section of the filter element according to the invention according to the first embodiment;

[0062] Fig. 3 is a plan view of the filter element according to the invention according to the first embodiment from the side of the opened end plate;

[0063] Fig. 4 is an isometric exploded view of a filter device according to the invention according to a first embodiment;

[0064] Fig. 5 is an isometric view of a filter device according to the invention according to the first embodiment;

[0065] Fig. 6 is a plan view of the filter device according to the invention according to the first embodiment from the side of the fluid outlet;

[0066] Fig. 7 is a longitudinal section of the filter device according to the invention according to the first embodiment;

[0067] Fig. 8 Detail X of Fig. 7;

[0068] Fig. 9 Section BB according to Fig. 7;

[0069] Fig. 10 is an isometric view of a filter element according to the invention according to a second embodiment;

[0070] Fig. 11 is a longitudinal section of the filter element according to the invention according to the second embodiment;

[0071] Fig. 12 is a plan view of the filter element according to the invention according to the second embodiment from the side of the opened end plate;

[0072] Fig. 13 is an isometric exploded view of a filter device according to the invention according to a second embodiment;

[0073] Fig. 14 is an isometric view of a filter device according to the invention according to the second embodiment;

[0074] Fig. 15 is a plan view of the filter device according to the invention according to the second embodiment from the side of the fluid outlet;

[0075] Fig. 16 is a longitudinal section of the filter device according to the invention according to the second embodiment;

[0076] Fig. 17 Detail C of Fig. 16;

[0077] Fig. 18 section BB according to Fig. 16; Fig. 19 an isometric view of a filter element according to the invention according to a third embodiment;

[0078] Fig. 20 is a plan view of the filter element according to the invention according to the third embodiment from the side of the opened end plate;

[0079] Fig. 21 is an isometric exploded view of a filter device according to the invention according to a third embodiment;

[0080] Fig. 22 is an isometric view of a filter housing part of a filter device according to the invention according to the third embodiment; and

[0081] Fig. 23 is a sectional view of a filter device according to the invention according to the third embodiment.

[0082] Embodiment(s) of the invention

[0083] Fig. 1 shows a filter element 1 according to the invention for filtering a fluid, in particular an air filter element for an air filter system, in particular for an intake air filter system of a fuel cell or internal combustion engine, according to a first embodiment of the invention. The filter element is a round filter element whose filter bellows 10 has a hollow cylindrical shape. The filter element 1 has a filter bellows 10 arranged around a longitudinal axis L, which encloses an interior space 11. The filter bellows 10 has a first end 101 and a second end 102 opposite the first end. At the first end 101, an end plate 12 is open to the interior space 11, wherein an opening of the open end plate 12 communicates fluidically with the interior space 11. At the second end 102, a further end plate 13 is arranged, which can in particular be a closed end plate 13.At least one circumferential sealing contour 14 is arranged on the end plate 12, which is open to the interior space 11. This sealing contour completely surrounds the opening in the open end plate 12. The circumferential sealing contour 14 rises in the direction of the longitudinal axis L from the end plate 12, which is open to the interior space 11.

[0084] The filter bellows 10 has a notch 105 on its outer circumference 103. The circumferential sealing contour 14 has a locally limited recess 141 with respect to the radial direction R in the region of the notch 105 on the outer circumference 103 of the filter bellows 10, wherein the recess 141 of the sealing contour 14 is arranged circumferentially such that its position corresponds to a circumferential position of the notch 105 on the outer circumference 103 of the filter bellows 10.

[0085] The filter bellows 10 comprises a plurality of folds 100, the radially outer fold edges of which lie in an outer circumferential surface and the radially inner fold edges of which lie in an inner circumferential surface. The fold edges of the folds 100 extend substantially parallel to the longitudinal axis L. The notch 105 on the outer circumference 103 of the filter bellows 10 is formed by a spreading 107 of at least one fold 100 of the filter bellows 10 on the outer circumference (see Fig. 9).

[0086] The folds 100 of the filter bellows 10 are particularly shaped like a star fold, whereby the folds can have a consistent cross-sectional shape over a large part of the circumference. In the area of ​​the notch 105 provided by the spreading portion 107 on the outer circumference 103, at least one fold 100 is widened.

[0087] The end plate 12, which is open to the interior, has a notch 121 on its outer circumference, which corresponds to the notch 105 on the outer circumference 103 of the filter bellows 10 and is aligned with the notch 105. The notch 121 can be understood as a local material recess of the open end plate 12 and extends inward from the outer circumference of the open end plate 12 with a radial component R. The notch has two opposing notch walls, which run at a particularly acute angle to each other.

[0088] The notch 105 on the outer circumference 103 of the filter bellows 10 is located at the first end 101 of the filter bellows 10 and is shorter in the direction of the longitudinal axis L than the total extension of the filter bellows 10; in particular, the notch 105 is present only in a longitudinal section of the filter bellows 10 close to the first end 101. The notch 105 provided as a spread 107 is reduced to a regular fold shape corresponding to the majority of the folds 100 of the filter bellows 10 in a longitudinal section of the filter bellows 10 remote from the first end 101, which can be seen in the figure by the structure of the spread 107 tapering towards the second end 102. The basic shape of the circumferential sealing contour 14 is a circle, with the circumferential profile of the circumferential sealing contour 14 deviating from the circular shape in the area of ​​the locally limited recess 141. The locally limited recess 141 forms a nose that protrudes inward from the circular shape.

[0089] The open end plate 12 comprises or consists of a plastic material, in particular a foamed plastic material, in particular a polyurethane foam. The circumferential sealing contour 14 is in particular integral with the end plate 12 open to the interior. The end plate 12 open to the interior is connected to the first end 101 of the filter bellows 10, in particular by means of a material bond, in particular by welding, adhesive bonding, or foam bonding.

[0090] A fluid-permeable support grid 15 is arranged on the inner circumference 104 of the filter bellows 10. This support grid is particularly designed to support the filter bellows 10 against differential pressures occurring during flow from the radial outside to the radial inside (clean side in the interior 11). The fluid-permeable support grid 15 can be embedded at the first end 101 in a material of the open end plate 12, in particular, enclosed by a foamed plastic material of the open end plate 12.

[0091] A plurality of pleat stabilizing means 109 are arranged on the outer circumference 103 of the filter bellows 10 and encircle the filter bellows 10. The pleat stabilizing means 109 are spaced apart from one another with respect to the longitudinal axis L. The pleat stabilizing means 109 support the pleats 100 of the filter bellows 10 and keep them in shape, which can be particularly important in the event of a sudden liquid load on a filter element 1 designed as an air filter element. The pleat stabilizing means 109 can be, for example, threads or yarn that are glued to the pleat tips of the filter bellows 10.

[0092] The circumferential sealing contour 14 can have a circumferential radial sealing surface 143 which is present on an inner circumference.

[0093] In the longitudinal section of Fig. 2, the notch 105, formed as a spread 107, on the outer circumference 103 of the filter bellows 10 can be seen more clearly; furthermore, the locally limited recess 141 with respect to the radial direction R of the circumferential sealing contour 14, which is arranged circumferentially such that its position corresponds to a circumferential position of the notch 105 on the outer circumference 103 of the filter bellows 10. This can be seen in particular in that the distance of the circumferential sealing contour 14 from the longitudinal axis L is smaller on the left side in the figure than on the right side in the figure.

[0094] The notch 105 formed as a spreading 107 on the outer circumference 103 of the filter bellows 10 comprises an intermediate fold with a fold base that runs obliquely with respect to the longitudinal axis.

[0095] Fig. 3 shows a plan view of the filter element 1 according to the first embodiment from the side of the open end plate 12, wherein the further end plate 13, which is a closed end plate here, can be seen through the interior space 11.

[0096] Fig. 4 shows an isometric exploded view of a filter device 200 according to the invention according to a first embodiment. The filter device 200 comprises a filter housing 20 with a fluid inlet 21 on a first housing part 201, in particular a housing pot 201, and with a fluid outlet 22 on the first housing part 201. The first housing part 201, designed as a housing pot 201, provides a receiving space 23 for a filter element 1, in which, in an assembled state, the filter element 1 can be arranged such that it separates a raw side assigned to the fluid inlet 21 from a clean side assigned to the fluid outlet 22.

[0097] The first housing part 201 has a circumferential housing sealing surface 24 against which the circumferential sealing contour 14 of the filter element 1 can be brought into contact (see Fig. 7), wherein the housing sealing surface 24 has a locally limited recess which corresponds to the one locally limited recess 141 of the circumferential sealing contour 14 of the filter element 1. Furthermore, the first housing part 201 comprises a housing projection 25 which projects into the receiving space 23 and which, in the assembled state, can be received in the notch 105 on the outer circumference 103 of the filter element 1, so that the filter element 1 is clearly positioned in the first housing part 201 with regard to its installed position about the longitudinal axis L. The filter housing 20 further comprises a second housing part 202 in the form of a housing cover 202, which can be detachably connected to the first housing part 201 in order to close the receiving space 23.

[0098] Fig. 5 shows the filter device 200 in the assembled state, ie with the filter element 1 inserted and the second housing part 202 detachably attached to the first housing part 201.

[0099] Fig. 6 shows a plan view of the filter device 200 according to the invention according to the first embodiment from the side of the fluid outlet 22, wherein the interior 11 of the filter element 1 and its further end plate 13 can be seen through the fluid outlet 22. The housing projection 25 extends inward from an outer wall of the first housing part 201 with a radial component and has a predetermined extent in the direction of the longitudinal axis, so that it can engage through the incision 121 of the open end plate 12 of the filter element 1 into the notch 105 formed as a spread 107 on the outer circumference 103 of the filter element 1. The housing projection 25 has two projection walls facing away from one another, which are at an acute angle to one another, resulting, for example, in a housing projection 25 with an overall triangular shape.

[0100] In Fig. 7, Fig. 8 and Fig. 9, the engagement of the housing projection 25 through the incision 121 on the outer circumference of the opened end plate 12 of the filter element 1 into the notch 105 formed as a spreading 107 on the outer circumference 103 of the filter element 1 can be seen even more clearly.

[0101] Fig. 9 further shows the structure of the notch 105, formed as a spread 107, on the outer circumference 103 of the filter element 1 in even better detail. The folds 100 of the filter bellows 10 are in the form of a star fold, wherein the folds 100 have a consistent cross-sectional shape over a large part of the circumference. In the region of the notch 105 provided by the spread 107 on the outer circumference 103, a fold 100 is widened, which means that a distance between fold edges adjacent to a fold valley or a fold peak on the outer circumference is increased compared to neighboring folds, so that the housing projection 25 can engage therein. Fig. 10 shows an isometric view of a filter element 1 according to the invention according to a second embodiment, which is very similar to the filter element 1 according to the first embodiment in terms of its basic structure, so that only the differences will be discussed.

[0102] The circumferential sealing contour 14 has, in the region of a notch 106 on the inner circumference 104 of the filter bellows 10, a locally limited projection 142 with respect to the radial direction R, wherein the projection 142 of the sealing contour 14 is arranged circumferentially such that its position corresponds to a circumferential position of the notch 106 on the inner circumference 104 of the filter bellows 10.

[0103] The notch 106 on the inner circumference 104 of the filter bellows 10 is formed by a spreading 108 of at least one fold 100 of the filter bellows 10 on the inner circumference 104 (see Fig. 18). The folds 100 of the filter bellows 10 are in particular in the shape of a star fold, whereby the folds can have a consistent cross-sectional shape over a large part of the circumference. In the region of the notch 106 on the inner circumference 104 provided by the spreading 108, at least one fold 100 is widened.

[0104] The end plate 12, which is open to the interior, has a notch 122 on its inner circumference, which corresponds to the notch 106 on the inner circumference 104 of the filter bellows 10 and is aligned with the notch 106. The notch 122 can be understood as a local material recess of the open end plate 12 and extends outward from the inner circumference of the open end plate 12 with a radial component R. The notch 122 has two opposing notch walls, which run at a particularly acute angle to each other.

[0105] The notch 106 on the inner circumference 104 of the filter bellows 10 is located at the first end 101 of the filter bellows 10 and is shorter in the direction of the longitudinal axis L than the total extension of the filter bellows 10; in particular, the notch 106 is only present in a longitudinal section of the filter bellows 10 close to the first end 101. The notch 106 provided as a spread 108 is reduced in a longitudinal section of the filter bellows 10 remote from the first end 101 to a regular fold shape corresponding to the majority of the folds 100 of the filter bellows 10, which can be seen in the figure by the structure of the spread 108 tapering towards the second end 102.

[0106] The basic shape of the circumferential sealing contour 14 is a circle, with a circumferential profile of the circumferential sealing contour 14 deviating from the circular shape in the region of the locally limited projection 142. The locally limited projection 142 forms a nose that protrudes outward from the circular shape.

[0107] A fluid-permeable support grid 15 is arranged on the inner circumference 104 of the filter bellows 10, which is particularly designed to support the filter bellows 10 against differential pressures that occur during flow from the radial outside to the radial inside (clean side in the interior 11). The fluid-permeable support grid 15 can be embedded at the first end 101 in a material of the open end plate 12, in particular in a foamed plastic material. The fluid-permeable support grid 15 has a radial bulge 151 that projects into the notch 106 present on the inner circumference 104 of the filter bellows 10 in order to support it.

[0108] In the longitudinal section of Fig. 11, the notch 106 formed as a spread 108 on the inner circumference 104 of the filter bellows 10 can be seen more clearly; furthermore, the locally limited projection 142 with respect to the radial direction R of the circumferential sealing contour 14, which is arranged circumferentially such that its position corresponds to a circumferential position of the notch 106 on the inner circumference 104 of the filter bellows 10. This can be seen in particular in that the distance of the circumferential sealing contour 14 from the longitudinal axis L is greater on the right side in the figure than on the left side in the figure.

[0109] The notch 105, formed as a spreading portion 108, on the inner circumference 104 of the filter bellows 10 comprises an intermediate fold with a fold base extending obliquely with respect to the longitudinal axis.

[0110] Fig. 12 shows a plan view of the filter element 1 according to the second embodiment from the side of the open end plate 12, wherein the further end plate 13, which is a closed end plate here, can be seen through the interior space 11. Fig. 13 shows an isometric exploded view of a filter device 200 according to the invention according to a second embodiment, which is very similar in terms of its basic structure to the filter device 200 according to the first embodiment, so that only the differences will be discussed. Deviating from the first embodiment, the first housing part 201 comprises a housing projection 25 which projects into the receiving space 23 and which, in the assembled state, can be received in the notch 106 on the inner circumference 104 of the filter element 1, so that the filter element 1 is clearly positioned in the first housing part 201 with regard to its installed position about the longitudinal axis L.The housing projection 25 is arranged in particular adjacent to an inner circumference of the fluid outlet 22 and extends outwards with a radial component and has a predetermined extension in the direction of the longitudinal axis, so that it can engage through the incision 122 of the opened end plate 12 of the filter element 1 into the notch 106 formed as a spread 108 on the inner circumference 104 of the filter element 1.

[0111] Fig. 14 shows the filter device 200 in the assembled state, ie with the filter element 1 inserted and the second housing part 202 detachably fastened to the first housing part 201, wherein the housing projection 25 engages in the notch 106 formed as a spread 108 on the inner circumference 104 of the filter element 1.

[0112] Fig. 15 shows a plan view of the filter device 200 according to the invention according to the second embodiment from the side of the fluid outlet 22, wherein the interior 11 of the filter element 1 and its further end plate 13 can be seen through the fluid outlet 22.

[0113] In Fig. 16, Fig. 17 and Fig. 18, the engagement of the housing projection 25 through the incision 122 on the inner circumference of the opened end plate 12 of the filter element 1 into the notch 106 formed as a spreading 108 on the inner circumference 104 of the filter element 1 can be seen even more clearly.

[0114] Fig. 18 further illustrates the structure of the notch 106, formed as a spread 108, on the inner circumference 104 of the filter element 1 in even better detail. The folds 100 of the filter bellows 10 are in the form of a star fold, with the folds 100 having a consistent cross-sectional shape over a large part of the circumference. In the region of the notch 106 provided by the spread 108 on the inner circumference 104, a fold 100 is widened, which means that the distance between fold edges adjacent to a fold valley or a fold peak on the inner circumference 104 is increased compared to neighboring folds, so that the housing projection 25 can engage therein.

[0115] Fig. 19 shows an isometric view of a filter element 1 according to the invention according to a third embodiment, which is very similar in terms of its basic structure to the filter element 1 according to the first and second embodiments, so that only the differences will be discussed.

[0116] The filter bellows 10 has a notch 105 on its outer circumference 103. The circumferential sealing contour 14 has a locally limited recess 141 with respect to the radial direction R in the region of the notch 105 on the outer circumference 103 of the filter bellows 10, wherein the recess 141 of the sealing contour 14 is arranged circumferentially such that its position corresponds to a circumferential position of the notch 105 on the outer circumference 103 of the filter bellows 10.

[0117] The filter bellows 10 comprises a plurality of folds 100, the radially outer fold edges of which lie in an outer circumferential surface and the radially inner fold edges of which lie in an inner circumferential surface. The fold edges of the folds 100 extend substantially parallel to the longitudinal axis L. The notch 105 on the outer circumference 103 of the filter bellows 10 is formed by a spreading 107 of at least one fold 100 of the filter bellows 10 on the outer circumference 103 (see Fig. 23).

[0118] The end plate 12, which is open to the interior, has a notch 121 in its outer circumference which corresponds to the notch 105 on the outer circumference 103 of the filter bellows 10 and is aligned with the notch 105.

[0119] The circumferential sealing contour 14 further has, in the region of a notch 106 on the inner circumference 104 of the filter bellows 10, a locally limited projection 142 with respect to the radial direction R, wherein the projection 142 of the sealing contour 14 is arranged circumferentially such that its position corresponds to a circumferential position of the notch 106 on the inner circumference 104 of the filter bellows 10. The notch 106 on the inner circumference 104 of the filter bellows 10 and the notch 105 on the outer circumference 103 of the filter bellows 10 are spaced apart from one another in the circumferential direction.

[0120] The end plate 12, which is open to the interior, has a notch 122 on its inner circumference which corresponds to the notch 106 on the inner circumference 104 of the filter bellows 10 and is aligned with the notch 106.

[0121] The basic shape of the circumferential sealing contour 14 is a circle, with the circumferential profile of the circumferential sealing contour 14 deviating from the circular shape in the area of ​​the locally limited projection 142 and the locally limited recess 141. The locally limited projection 142 forms a nose that protrudes outward from the circular shape. The locally limited recess 141 forms a nose that protrudes inward from the circular shape.

[0122] The fluid-permeable support grid 15 has a radial bulge 151 which projects into the notch 106 present on the inner circumference 104 of the filter bellows 10 in order to support it.

[0123] Fig. 20 shows a plan view of the filter element 1 according to the third embodiment from the side of the opened end plate 12, wherein the further end plate 13, which is a closed end plate here, can be seen through the interior space 11.

[0124] Fig. 21 shows an isometric exploded view of a filter device 200 according to the invention according to a third embodiment, which is very similar in terms of its basic structure to the filter device 200 according to the first embodiment and the second embodiment, so that only the differences will be discussed. The first housing part 201 has a first housing projection 25 which projects into the receiving space 23 and which, in the assembled state, can be received in the notch 106 on the inner circumference 104 of the filter element 1. Furthermore, the first housing part 201 has a second housing projection 25 which projects into the receiving space 23 and, in the assembled state, can be received in the notch 105 on the outer circumference 103 of the filter element 1. Fig. 22 shows an isometric view of the first filter housing part 201 of the filter device according to the invention according to the third embodiment.The first filter housing part 201 is, in particular, a housing pot 201 with a receiving space 23 for the filter element 1. The first filter housing part 201 has two housing projections 25, of which a first housing projection 25 can be received in the notch 106 on the inner circumference 104 of the filter element 1 in the assembled state, and a second housing projection 25 can be received in the notch 105 on the outer circumference 103 of the filter element 1 in the assembled state. The housing sealing surface 24 has a locally limited projection that corresponds to the locally limited projection 142 of the circumferential sealing contour 14 of the filter element 1. Furthermore, the housing sealing surface 24 has a locally limited recess that corresponds to the locally limited recess 141 of the circumferential sealing contour 14 of the filter element 1. The projection and the recess of the housing sealing surface 24 are spaced apart from each other in the circumferential direction.

[0125] Fig. 23 shows the structure of the notch 105, formed as a spread 107, on the outer circumference 103 of the filter element 1 in even better detail. The folds 100 of the filter bellows 10 are in the form of a star fold, with the folds 100 having a consistent cross-sectional shape over a large part of the circumference. In the area of ​​the notch 105 on the outer circumference provided by the spread 107, one fold 100 is widened so that the second housing projection 25 can engage therein.

[0126] Furthermore, the structure of the notch 106 formed as a spread 108 on the inner circumference 104 of the filter element 1 can be seen: In the area of ​​the notch 106 provided by the spread 108 on the inner circumference 104, a fold 100 is widened so that the first housing projection 25 can engage therein. Reference numerals used:

[0127] I Filter element

[0128] 10 filter bellows

[0129] 100 folds

[0130] 101 Frontal first end

[0131] 102 Frontal second end

[0132] 103 outer circumference

[0133] 104 inner circumference

[0134] 105 Notch on the outer circumference

[0135] 106 Notch on the inner circumference

[0136] 107 Spreading on the outer circumference

[0137] 108 Spreading on the inner circumference

[0138] 109 Wrinkle stabilizers

[0139] II Interior

[0140] 12 end plate open to the interior

[0141] 121 Incision on the outer circumference

[0142] 122 Incision on the inner circumference

[0143] 13 additional end plates, especially closed end plates

[0144] 14 circumferential sealing contour

[0145] 141 Recess of the circumferential sealing contour

[0146] 142 Projection of the circumferential sealing contour

[0147] 143 Radial sealing surface

[0148] 15 support grids

[0149] 151 bulge

[0150] 200 filter device

[0151] 20 filter housings

[0152] 201 housing pot

[0153] 202 housing cover

[0154] 21 Fluid inlet

[0155] 22 Fluid outlet

[0156] 23 Recording room

[0157] 24 Housing sealing surface

[0158] 25 Housing projection

[0159] L Longitudinal axis

[0160] R Radial direction

Claims

Claims 1. Filter element (1) for filtering a fluid, in particular an air filter element for an air filter system, in particular for an intake air filter system of a fuel cell or internal combustion engine, comprising a filter bellows (10) arranged around a longitudinal axis (L) which at least partially encloses an interior space (11), wherein the filter bellows (10) has a frontal first end (101) and a frontal second end (102) opposite thereto, and an end plate (12) open to the interior space (11) at the first end (101) and a further end plate (13), in particular a closed end plate (13), at the opposite second end (102), wherein at least one circumferential sealing contour (14) is arranged on the end plate (12) open to the interior space (11), which sealing contour rises in the direction of the longitudinal axis (L) from the end plate (12) open to the interior space (11), characterized in thatthat the filter bellows (10) has at least one notch (105, 106) on its outer circumference (103) and / or inner circumference (104), and that the circumferential sealing contour (14) in the region of the notch (105, 106) of the filter bellows (10) has at least one locally limited projection or recess (141, 142) with respect to a radial direction (R), wherein the projection or recess (141, 142) of the sealing contour (14) is arranged circumferentially such that its position corresponds to a circumferential position of the notch (105, 106) of the filter bellows (10).

2. Filter element (1) according to claim 1, wherein the filter bellows (10) has a plurality of folds (100), the radially outer fold edges of which lie in an outer circumferential surface and the radially inner fold edges of which lie in an inner circumferential surface, the notch (105, 106) being formed by a spreading (107, 108) of at least one fold (100) of the filter bellows (10) on the inner and / or outer circumference.

3. Filter element (1) according to claim 1 or 2, wherein the end plate (12) open to the interior has at least one notch (121, 122) corresponding to the notch (105, 106) of the filter bellows (10) and aligned with the at least one notch (105, 106).

4. Filter element (1) according to one of the preceding claims, wherein the notch (105, 106) is present at least at the first end (101) of the filter bellows (10).

5. Filter element (1) according to one of the preceding claims, wherein the notch (105, 106) extends in the direction of the longitudinal axis (L) over an entire extent of the filter bellows (10).

6. Filter element (1) according to one of the preceding claims, wherein the notch (105, 106) in the direction of the longitudinal axis (L) is shorter than the total extension of the filter bellows (10) and in particular is present only in a longitudinal section of the filter bellows (10) close to the first end (101).

7. Filter element (1) according to one of the preceding claims, wherein the circumferential sealing contour (14) has a predetermined basic shape, and wherein a circumferential course of the circumferential sealing contour (14) deviates from the predetermined basic shape in the region of the locally limited projection or recess (141, 142).

8. Filter element (1) according to claim 7, wherein the predetermined basic shape is a circular shape.

9. Filter element (1) according to one of the preceding claims, wherein the filter bellows (10) has a hollow cylindrical shape and in particular completely surrounds the interior (11).

10. Filter element (1) according to one of the preceding claims, wherein the end plate (12) open to the interior (11) comprises or consists of a plastic material, in particular a foamed plastic material, in particular a polyurethane foam, wherein in particular the circumferential sealing contour (14) is in one piece with the end plate (12) open to the interior (11).

11. Filter element (1) according to one of the preceding claims, wherein the filter element (1) has a fluid-permeable support grid (15) arranged on the inner circumference (104) of the filter bellows (10), which in particular has a radial bulge (151) which projects into a notch (106) present on the inner circumference (104) of the filter bellows (10).

12. Filter element (1) according to one of the preceding claims, wherein the filter bellows (10) has at least two notches (105, 106) spaced apart in the circumferential direction on its outer and / or inner circumference (103, 104), and wherein the circumferential sealing contour (14) in the region of the notches (105, 106) of the filter bellows (10) has a locally limited projection or recess (141, 142) with respect to the radial direction (R), wherein the respective projection or recess (141, 142) of the sealing contour (14) is arranged circumferentially such that its position corresponds to a circumferential position of the respective notch (105, 106) of the filter bellows (10).

13. Filter element (1) according to claim 12, wherein a first notch (106) is present on the inner circumference (104) and a second notch (105) is present on the outer circumference (103) of the filter bellows (10).

14. Filter element (1) according to claim 12 or 13, wherein the end plate (12) open to the interior (11) has incisions (121, 122) corresponding to the notches (105, 106) of the filter bellows (10), which incisions are each aligned with a notch (105, 106) of the filter bellows (10).

15. Filter element (1) according to one of the preceding claims, wherein the circumferential sealing contour (14) provides at least one circumferential radial sealing surface (143), in particular on an inner circumference.

16. Filter device (200), comprising a filter housing (20) with a fluid inlet (21) and a fluid outlet (22) and a receiving space (23) for a filter element, in which a filter element is arranged such that it separates a raw side assigned to the fluid inlet (21) from a clean side assigned to the fluid outlet (22), characterized in that the filter element is a filter element (1) according to one of the preceding claims.

17. Filter device (200) according to claim 16, wherein the filter housing (20) has at least one circumferential housing sealing surface (24) against which the circumferential sealing contour (14) of the filter element (1) rests, wherein the housing sealing surface (24) has at least one locally limited projection or recess which corresponds to the at least one locally limited projection or recess (141, 142) of the circumferential sealing contour (14) of the filter element (1).

18. Filter device (200) according to claim 16 or 17, wherein the filter housing (20) has at least one housing projection (25) projecting into the receiving space (23) and received in the at least one notch (105, 106) of the filter element (1).

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