Filter element and filter device

Abstract

The present invention relates to a 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. The filter element (1) comprises at least one filter medium body (10) having at least one filter medium, through which filter medium body a fluid to be cleaned can flow from an upstream side (105) to a downstream side (106) in a flow direction (D), and at least one sealing device (14) which is arranged on the filter medium body (10) and has at least one circumferentially extending sealing surface (141). The sealing surface (141) has, in at least one circumferential portion, a wave-like profile, which has a period and / or amplitude which is variable in the circumferential direction. The invention also relates to a filter device having such a filter element (1).

Description

[0001] Filter element and filter device

[0002] This patent application claims priority from German patent application 102023134990.2, filed with the German Patent and Trademark Office on December 13, 2023, the contents of which are hereby incorporated by reference.

[0003] Technical area

[0004] 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.

[0005] 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.

[0006] 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.

[0007] 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.

[0008] Alternatively, such filter elements or filter inserts can also be designed as so-called flat elements, which typically have a prismatic, particularly cuboid-shaped, filter bellows. The filter bellows is permeable to flow along a longitudinal axis and has a circumferential seal arranged along an outer periphery of the filter bellows.

[0009] For various reasons, it may be technically necessary for filter elements or filter inserts to be installed in a predetermined position within a filter housing. 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 generally calibrated to a predetermined installation position of the filter element or filter insert, so that if the filter element or filter insert is installed in the filter housing in a position deviating from the predetermined installation position, measurement inaccuracies may occur. In the case of round elements, the reason for this is that the filter bellows usually have a junction that influences the downstream flow profile. State of the art

[0010] EP 3 370 849 A1 discloses a filter element with a filter medium body through which flow can occur, in particular, along a longitudinal axis. A sealing element is mounted on a lateral surface of the filter medium body, which sealing element has at least one sealing surface that has a regular, undulating shape over the circumference. The axial distance of the sealing surface from an inflow or outflow surface of the filter medium body varies over the circumference due to the undulation.

[0011] Furthermore, EP 3 441 124 A1 discloses a filter element with a radially flowable filter medium body, which is axially delimited at each end by an end plate. One of the end plates is an open end plate, which has an opening that fluidically communicates with an interior space enclosed by the filter medium body. A circumferential sealing structure is present on the open end plate, which surrounds the opening. The circumferential sealing structure has a regular, wave-like crown shape and rises from the open end plate along the longitudinal axis.

[0012] The disadvantage of this state of the art is that, due to the regular wave shape, no clear installation position in a filter housing can be defined.

[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 better than before.

[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 23. 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, for example, for filtering oil, fuels, water, or aqueous solutions.

[0017] The filter element according to the invention comprises at least one filter medium body with at least one filter medium through which a fluid to be cleaned can flow from an upstream side to a downstream side in a flow direction, and at least one sealing device arranged on the filter medium body. The sealing device has at least one circumferentially extending sealing surface, which has a wave-shaped profile in at least one circumferential section, which has a variable period and / or amplitude in the circumferential direction.

[0018] The term "filter medium body," in its broadest sense, encompasses any body that has at least one filter medium, which may be in pleated or unfolded form. The filter medium may, in particular, be a particle filter medium or a gas filter medium. Optionally, the filter medium may comprise at least one adsorbent, in particular activated carbon. A filter medium configured as a particle filter medium may, in particular, comprise a nonwoven material, in particular made of synthetic fibers and / or cellulose fibers.

[0019] A waveform with a circumferentially variable period and / or amplitude represents a technically simple option for the sealing surface to specify a defined installation orientation for the filter element.

[0020] The circumferential section of the sealing surface with the wave-shaped course with a variable period and / or amplitude in the circumferential direction can in particular have a rotationally asymmetric structure, so that a mandatory angular orientation of the filter element with respect to a filter housing is enabled, which considerably reduces the possibilities of misusing the filter element in a filter housing deviating from its predetermined angular position.

[0021] In embodiments, the circumferential sealing surface can have a wave-like profile over its entire circumference, in particular with the period and / or amplitude being variable over the entire circumference. In other embodiments, the circumferential sealing surface can have a wave-like profile with a circumferentially variable period and / or amplitude only over part of its circumference and have a flat profile in other circumferential sections.

[0022] In particular, the wave-shaped profile can be transverse wave-like. Alternatively or additionally, the wave-shaped profile can have a sine wave-like profile, a rectangular wave-like profile, a triangular wave-like profile, a sawtooth wave-like profile, or a profile formed by a spline curve.

[0023] Relative to the longitudinal axis, a transverse wave-like profile of the sealing surface can have a direction of propagation in the circumferential direction and a "direction of oscillation" in the radial and / or axial direction. This can create a sealing surface with a wave-like profile that has a variable axial and / or radial position over the circumference. It is explicitly possible for the wave-like profile to be formed by the superposition of at least two transverse waves. A first transverse wave can have a direction of oscillation in the radial direction, and a second transverse wave can have a direction of oscillation in the axial direction.

[0024] A sine wave-like course of the sealing surface with a circumferentially variable period and / or amplitude can be described by the following general functional equation: (fe ■ x c) ■ D(x)| where x is a circumference coordinate, a is a constant that modifies the amplitude, b is a constant that modifies the period, c is a constant that modifies a variability of the period over the circumference and

[0025] D(x) is a function of the circumference coordinate, for example a polynomial, a

[0026] Hyperbolic function, a logarithmic function, which allows for variability of

[0027] Amplitude is modified across the circumference. For a wave-like sealing surface with a circumferentially variable period (and constant amplitude), D(x) can be a constant. For a wave-like sealing surface with a circumferentially variable amplitude (and constant period), c can be 1.

[0028] In embodiments, the term x c be replaced by another term that allows a modification of the variability of the period the extent.

[0029] Depending on whether the above-mentioned general functional equation is intended to describe a wave-like pattern with a "direction of oscillation" in the radial and / or axial directions, f(x) can describe an axial coordinate (parallel to the longitudinal axis) or a radial coordinate (normal to the longitudinal axis). The circumferential coordinate x can be expressed in Cartesian or polar coordinates, depending on the application. A representation in polar coordinates makes it particularly easy to represent the wave-like pattern as a deviation from an ideal circular shape.

[0030] To describe the wave-like course of the sealing surface with a circumferentially variable period and / or amplitude, based on a predetermined basic shape of a circumferential sealing line defined by the sealing surface, the above-mentioned general functional equation can be superimposed with a term describing the basic shape. The predetermined basic shape can, in particular, be a circle. However, other basic shapes are also possible, such as an oval, flat oval, or rectangular shape.

[0031] According to a further embodiment, the filter medium body can be arranged around a longitudinal axis and at least partially enclose an interior space. In particular, the filter medium body can be permeable to flow in the radial direction relative to the longitudinal axis.

[0032] The filter medium body can, in particular, completely encircle the interior, whereby the originally free circumferential ends (in pleated filter bellows: the so-called "end pleats") can be connected to one another during production to form a circumferentially "endless" filter medium body. However, in some embodiments, an adapter part can also be arranged between the originally free circumferential ends during production, connecting the originally free circumferential ends to one another.

[0033] The filter medium body 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 region of the interior space enclosed by the filter medium body. However, in some embodiments, flow from radially inside to radially outside is also possible, so that a dirty side can be present in the region of the interior space enclosed by the filter medium body.

[0034] According to yet another embodiment, a fluid-permeable support grid can be arranged in the interior space, wherein the support grid in particular supports the filter medium body on an inner circumferential surface that borders the interior space. The support grid can in particular be designed as a support tube having a plurality of openings. The support tube can have a plurality of struts that extend in particular in the circumferential direction and / or longitudinal direction, wherein the filter medium body can be supported with its inner circumferential surface on the struts.

[0035] In a further development, the filter medium body can have a first end and a second end opposite the first end along the longitudinal axis. The filter element can have an end plate open to the interior at the first end of the filter medium body and another end plate, in particular a closed end plate, at the opposite second end of the filter medium body. The sealing device can be arranged on the end plate open to the interior.

[0036] “First end” and “second end” herein refer in particular to ends of the filter medium body facing away from each other with respect to the longitudinal axis.

[0037] In certain 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. In particular, the sealing device with the at least one circumferentially extending sealing surface can be integral 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.

[0038] Advantageously, the sealing device with the at least one circumferentially extending sealing surface together with the end plate open to the interior can be manufactured in a casting process using a foamable and flowable plastic material, so that the provision of the wave shape does not result in any additional manufacturing effort.

[0039] In a further development, a support grid arranged in the interior space can comprise, at an end close to the first end of the filter bellows, an end section which can be embedded in a material of the end plate open to the interior space.

[0040] According to a further embodiment, the sealing device can comprise a circumferential sealing profile which rises in the direction of the longitudinal axis from the end plate open to the interior and which has the circumferentially extending sealing surface.

[0041] According to yet another embodiment, the circumferential sealing profile can be in one piece with the end plate open to the interior, in particular wherein the end plate open to the interior is formed together with the circumferential sealing profile onto the filter medium body, in particular foamed, cast, welded or glued.

[0042] In alternative embodiments, the sealing device can also be arranged at a position different from the end plate, for example, on a lateral surface of the filter medium body. The sealing device can in particular be located at an axial position that is closer to the end plate open to the interior than to a closed end plate. Furthermore, the sealing device can comprise an at least partially circumferential seal carrier that carries a circumferential sealing profile providing the at least one sealing surface.

[0043] In embodiments, the filter medium body may have a hollow cylindrical shape, in particular with a circular, elliptical, oval, long oval and / or kidney-shaped cross-sectional shape.

[0044] 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. According to a further embodiment, the filter medium body at the first end can have, in at least one circumferential section, a wave-shaped profile with respect to an axial direction defined by the longitudinal axis, which has a period and / or amplitude that is variable in the circumferential direction and corresponds to the wave-shaped profile of the circumferentially extending sealing surface. The wave-shaped profile of the filter medium body at the first end can be formed in particular by an axial trimming of the filter medium body. The end plate that is open towards the interior can follow the wave-shaped profile of the filter medium body at the first end.If the filter medium body is a filter bellows made of folded filter medium, the trimming can be produced before folding in a flat state of the filter medium, for example by means of a laser cutting device.

[0045] Alternatively, the first end of the filter medium body can lie in a plane. In particular, the first end can lie in a normal plane with respect to the longitudinal axis or extend at an acute angle to the normal plane. A section extending at least partially axially between the first end of the filter medium body and the circumferentially extending sealing surface can be bridged by an at least partially circumferential flow guide body. Preferably, the flow guide body is completely circumferential. The flow guide body can be connected directly or indirectly to the first end of the filter medium body.

[0046] The flow guide body can be a plastic component. The flow guide body can be formed separately from the end plate open to the interior. Alternatively, the flow guide body can also be formed by a flow guide section of the end plate open to the interior and, in particular, can be formed integrally with the end plate.

[0047] According to yet another embodiment, the filter medium body can comprise a round filter bellows made of a filter medium with a plurality of folds, the radially outer fold edges of which lie in an outer lateral surface and the radially inner fold edges of which lie in an inner lateral surface. The inner lateral surface borders the interior space.

[0048] The round filter bellows can in particular have a closed cross-section.

[0049] The pleats of the round filter bellows can, in particular, be in the form of a star pleat, whereby the pleats can have a consistent cross-sectional shape, particularly over a large part of the circumference. The majority of pleats can be in the form of a V-fold with fold heights that remain constant over the circumference. Alternatively, the majority of pleats can also be in the form of a W- or M-fold with intermediate folds of a reduced pleat height.

[0050] In embodiments, the circumferential sealing surface can comprise at least one circumferential radial sealing surface, which is present in particular on an inner circumference of the circumferential sealing profile.

[0051] However, the circumferential sealing profile can also 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 profile to have at least one axial sealing surface, in particular on an end face of the circumferential sealing profile. The sealing profile can have a predetermined cross-section, which 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.

[0052] According to an alternative development, the upstream and downstream sides of the filter medium body can be spaced apart from one another along the longitudinal axis, and the filter medium body can be permeable along the longitudinal axis. The sealing device can be arranged on or adjacent to an outer periphery of the filter medium body.

[0053] The filter medium body can in particular have a flat filter bellows made of a filter medium with a plurality of folds, the inflow-side fold edges of which are present on the upstream side, in particular in an inflow plane, and the outflow-side fold edges of which are present on the downstream side, in particular in an outflow plane.

[0054] The filter medium body can in particular have the shape of a prism, in particular a straight prism, in particular wherein the filter medium body is at least partially cuboid-shaped.

[0055] According to a further embodiment, the filter element can comprise a frame device that at least partially encloses the filter medium body at its outer periphery. The sealing device can be arranged on a side surface of the frame device facing away from the filter medium body, in particular with the sealing device projecting radially beyond the frame device.

[0056] The frame device can comprise a frame element that completely encloses the filter medium body. The frame element can comprise or consist of a plastic material, which can in particular be glued or injection-molded onto the filter medium body. Alternatively or additionally, the frame element can be formed from a textile material, such as a spunbonded fabric, and can comprise at least one so-called side band at the end edges of a folded filter medium body and at least one so-called head band at the end folds of a folded filter medium body. The frame device advantageously functions as a mechanical support structure for the sealing device.

[0057] According to yet another embodiment, it is possible for the sealing device to be arranged in the region of a circumferential outer edge of the filter medium body, in particular on the upstream or downstream side of the filter medium body, directly on the filter medium body. In particular, the sealing device can comprise a plastic material, in particular a foamed plastic material, in particular a polyurethane foam. The sealing device can in particular be molded, in particular foamed, directly onto a circumferential outer edge of the filter medium body, in particular on the upstream or downstream side.In this case, the sealing device - seen in cross section - can comprise an axial connecting leg extending along a lateral surface of the filter medium body and / or a radial connecting leg extending along an inflow or outflow plane of the filter medium body in order to achieve a mechanically loadable connection of the sealing device to the filter medium body.

[0058] In embodiments, the circumferentially extending sealing surface in the at least one circumferential section with a wave-shaped profile can have an axial distance, which varies in the circumferential direction, from a reference plane extending in the normal direction to the longitudinal axis. The reference plane can, in particular, coincide with the end plate open to the interior, the first end of the filter medium body, and / or with an inflow or outflow plane.

[0059] Alternatively or additionally, the circumferentially extending sealing surface in the at least one circumferential section with a wave-shaped profile can have a radial distance from a surface enclosing the filter medium body that varies in the circumferential direction. The surface enclosing the filter medium body can, in particular, be a lateral surface of the filter medium body.

[0060] Alternatively or additionally, the circumferentially extending sealing surface in the at least one circumferential section with a wave-shaped profile can have a radial distance from the longitudinal axis that varies in the circumferential direction.

[0061] The sealing device with the at least one circumferential section with a wave-shaped course of the sealing surface can in particular be designed to be rotationally asymmetrical.

[0062] The undulating profile of the sealing surface can have at least two troughs and / or crests, in particular at least three troughs and / or crests, in particular at least four troughs and / or crests. With a circumferentially variable period of the undulating profile, troughs and / or crests adjacent to a trough or crest each have different spacings. With a circumferentially variable amplitude of the undulating profile, troughs and / or crests adjacent to a trough or crest each have different deflections (maxima and / or minima).

[0063] 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.

[0064] 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.

[0065] Preferably, the filter housing has at least one circumferential housing sealing surface against which the circumferentially extending sealing surface of the filter element rests, wherein the housing sealing surface has, in at least one circumferential section, a wave-shaped profile with a period and / or amplitude variable in the circumferential direction, which corresponds to the wave-shaped profile of the sealing surface of the filter element.

[0066] The filter housing can in particular be two-part and have a housing pot containing the receiving space and a housing cover that is detachably connected or connectable to the housing pot. The housing sealing surface can be located either on the housing pot or on the housing cover. The interaction between the housing sealing surface and the sealing surface of the filter element represents the main functional interface between the filter housing and the filter element. The main interface can only fulfill its main function, namely sealing the raw side from the clean side, if the housing sealing surface matches the structure of the sealing surface of the filter element, wherein the housing sealing surface in particular can have the shape of a negative form of the sealing surface of the filter element, at least in sections.

[0067] Since in some designs both the housing sealing surface and the sealing surface 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.

[0068] 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.

[0069] 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.

[0070] Short description of the drawings

[0071] The invention will be explained in more detail below using exemplary embodiments with reference to the accompanying figures. In the figures:

[0072] Fig. 1 is an isometric view of a filter element according to the invention according to a first embodiment;

[0073] Fig. 2 is a longitudinal section of the filter element according to the invention according to the first embodiment;

[0074] 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;

[0075] Fig. 4 is a schematic representation of an axial distance of the circumferential sealing surface from a reference plane over the circumference, which has a wave-shaped course;

[0076] Fig. 5 is an isometric view of a filter element according to the invention according to a second embodiment;

[0077] Fig. 6 is a longitudinal section of the filter element according to the invention according to the second embodiment;

[0078] Fig. 7 is an isometric view of a filter element according to the invention according to a third embodiment;

[0079] Fig. 8 is a longitudinal section of the filter element according to the invention according to the third embodiment;

[0080] Fig. 9 is an isometric view of a filter element according to the invention according to a fourth embodiment;

[0081] Fig. 10 is a longitudinal section of the filter element according to the invention according to the fourth embodiment;

[0082] Fig. 1 1 is an isometric view of a filter element according to the invention according to a fifth embodiment;

[0083] Fig. 12 is a longitudinal section of the filter element according to the invention according to the fifth embodiment; Fig. 13 is a plan view of the filter element according to the invention according to the fifth embodiment from the side of the opened end plate;

[0084] Fig. 14 is an isometric view of a filter element according to the invention according to a sixth embodiment;

[0085] Fig. 15 is a longitudinal section of the filter element according to the invention according to the sixth embodiment;

[0086] Fig. 16 is an isometric view of a filter element according to the invention according to a seventh embodiment;

[0087] Fig. 17 Projection views of the filter element according to the invention according to the seventh embodiment;

[0088] Fig. 18 an example of a wave-like course with radial “oscillation direction”;

[0089] Fig. 19 shows another example of a wave-shaped course with a radial “oscillation direction” and Fig. 20 shows yet another example of a wave-shaped course with a radial “oscillation direction”.

[0090] Embodiment(s) of the invention

[0091] 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 medium body 10 is designed as a filter bellows 10 and 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 arranged, which is open towards 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 may in particular be a closed end plate 13. Furthermore, a radial direction R is shown in the figures, which extends outwardly from the longitudinal axis L at a 90° angle.

[0092] The filter medium body 10, designed as a filter bellows 10, can be flowed through along a flow direction D from radially outside to radially inside, so that a clean side can be present in the interior 11. The filter medium body 10 has a circular-cylindrical shape with an outer surface 103, on which an upstream side 105 can be present, and with an inner surface 104, on which a downstream side 106 can be present. However, the filter element 1 can also be flowed through in a different direction, ie from radially inside to radially outside, so that the upstream side 105 can be present on the inner surface 104.

[0093] A sealing device 14 is arranged on the end plate 12, which is open to the interior space 11. The sealing device 14 has at least one circumferentially extending sealing surface 141, 143. The circumferentially extending sealing surface 141, 143 has a wave-shaped profile with a variable period and amplitude in the circumferential direction.

[0094] The sealing device 14 comprises a circumferential sealing profile 142, which rises in the direction of the longitudinal axis L from the end plate 12 open to the interior space 11 and has a circumferentially extending axial sealing surface 141 and / or a circumferentially extending radial sealing surface 143 on an inner circumference of the sealing profile 142. The circumferential sealing profile 142 is in particular integral with the end plate 12 open to the interior space 11. Preferably, the end plate 12 open to the interior space 11 is integrally formed with the filter medium body 10 together with the circumferential sealing profile 142. In order to establish a fluid-tight and mechanically resilient connection to the filter medium body 10, the filter medium body 10 is embedded with its first end 101 in a material of the end plate 12, wherein the material of the end plate 12 penetrates into the filter medium body 10 along a predetermined penetration depth along the axial direction.

[0095] The circumferential sealing surface 141, 143 has a wave-like profile over its entire circumference, in particular, wherein the period and / or amplitude is variable over the entire circumference (see Fig. 4). The wave-like profile of the sealing surface 141, 143 has a transverse wave-like and sine wave-like profile and / or is formed by a spline curve.

[0096] The filter medium body 10 has, at the first end 101, a wave-shaped profile with respect to the axial direction, which has a period and / or amplitude that varies in the circumferential direction. In other words, the height of the filter medium body 10 is variable over the circumference. The wave-shaped profile of the filter medium body 10 at the first end 101 corresponds to the wave-shaped profile of the circumferentially extending sealing surface 141, 143. The wave-shaped profile of the filter medium body 10 at the first end 101 is formed by an axial trimming of the filter medium body 10. The end plate 12, which is open to the interior 11, follows the three-dimensional contour of the filter medium body 10 at the first end 101 provided by the trimming, which contributes to economical use of material in the production of the end plate 12.

[0097] The circumferentially extending sealing surface 141, 143 has an axial distance Dxi (see Fig. 2) which varies in the circumferential direction from a reference plane PR which runs in the normal direction to the longitudinal axis L.

[0098] In relation to the longitudinal axis, the circumferentially extending sealing surface 141, 143 has a transverse wave-like shape, the “oscillation direction” of which runs in the axial direction, so that the circumferentially extending sealing surface 141, 143 has a variable axial position over the circumference.

[0099] A fluid-permeable support grid 15 is arranged on the inner surface 104 of the filter medium body 10. This support grid is particularly designed to support the filter medium body 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 with an end section 151 (see Fig. 2) in a material of the open end plate 12, in particular, it can be enclosed by a foamed plastic material of the open end plate 12.

[0100] 1, wherein the sectional plane runs through a longitudinal center plane. The reference plane P runs in the normal direction to the longitudinal axis L and contains the first end 101 of the filter medium body 10 at a circumferential position which is cut on the left side in the figure. The axial distance between the circumferentially extending sealing surface 141, in particular axial sealing surface 141, and the reference plane PR is marked Dxi on a left side in the figure and Dx2 on a right side in the figure. It can be seen that Dx2>Dxi, since the distance Dxi varies over the circumference because the circumferentially extending sealing surface 141, 143 follows an (axial) wave shape. The reference plane PR can in principle also be arranged at other positions, which merely results in a different offset of the values ​​of Dxi and Dx2.

[0101] Furthermore, the height of the filter medium body 10 is marked HBI on a left-hand side in the figure and HB2 on a right-hand side in the figure. It can be seen that HB2 > HBI because the distance Hßi varies over the circumference, since the first end 101 of the filter medium body has a wave-shaped profile when viewed over the circumference, which has a period and / or amplitude that is variable in the circumferential direction and corresponds to the wave-shaped profile of the circumferentially extending sealing surface 141, 143. The heights Hßi of the filter medium body 10 that vary over the circumference can be produced in particular by an axial trimming of the filter medium body 10.

[0102] Fig. 3 shows a plan view of the filter element 1 according to the invention of Fig. 1 from the side of the open end plate 12, wherein it can be seen that the sealing device 14 with the circumferentially extending sealing surface(s) 141, 143 has a circular shape in a projection along the longitudinal axis L. According to the first embodiment, the wave shape of the circumferentially extending sealing surface(s) 141, 143 relates exclusively to the axial direction.

[0103] Fig. 4 shows a schematic representation of an axial distance Dxi of the circumferentially extending sealing surface from the reference plane P over the circumference in a developed view over the entire circumference of the sealing device 14 (0° to 360°). The wave-shaped course has both a variable period and a variable amplitude over the circumference and has four wave crests 144 and four wave troughs 145 distributed over the circumference. This results in a structure that is distinctly rotationally asymmetrical with respect to the longitudinal axis, so that - with a corresponding design of a housing sealing surface of a filter housing - a predetermined installation angular position can be reliably enforced.

[0104] Figs. 5 and 6 show a second embodiment of the filter element 1 according to the invention. Since the filter element 1 according to the second embodiment is very similar to the filter element 1 of the first embodiment, only the differences will be discussed below. Otherwise, features disclosed with respect to the first embodiment are transferable to the second embodiment and vice versa.

[0105] The filter element 1 of the second embodiment differs from the first embodiment only in that a material of the end plate 12, which is open to the interior space 11, has a variable penetration depth along the axial direction L into the filter medium body 10, viewed over the circumference, so that a penetration plane is formed that points toward the filter medium body 10 and is defined by the end plate material penetrating the filter medium body 10. This penetration plane extends in a normal direction to the longitudinal axis L and can, for example, coincide with a position of the reference plane PR. A filter element 10 according to this second embodiment can be easily manufactured using established production methods, but requires increased material usage with regard to the end plate material.

[0106] Fig. 5 also shows folds 100 of the filter medium body 10, whose fold edges run parallel to the longitudinal axis L. Radially outer fold edges define the outer surface 103, while radially inner fold edges define the inner surface 104. The filter medium body 10 is preferably a round filter bellows made of a pleated filter medium. This feature is explicitly not reserved for the second embodiment, but can be combined as desired with all other embodiments relating to round filter elements.

[0107] Figs. 7 and 8 show a third embodiment of the filter element 1 according to the invention. Since the filter element 1 according to the third embodiment is very similar to the filter element 1 of the second embodiment, only the differences will be discussed below. Otherwise, features disclosed with respect to the first and / or second embodiment are transferable to the third embodiment and vice versa.

[0108] The filter element 1 of the third embodiment differs from the second embodiment in that the first end 101 of the filter medium body 10 does not have a wavy shape. Rather, the first end 101 of the filter medium body 10 lies in a plane, namely in a normal plane with respect to the longitudinal axis L. A section extending axially over the entire circumference between the first end 101 of the filter medium body 10 and the circumferentially extending sealing surface 141, 143 or the sealing profile 142 is bridged by a circumferentially extending flow guide body 16. The flow guide body 16 is, in particular, directly connected to the first end 101 of the filter medium body 10.

[0109] The flow guide body 16 is formed in particular by a flow guide section of the end plate 12 open to the interior and is designed in one piece with the end plate 12. This results in a thickness of the end plate 12 that varies over the circumference, which can be seen in Fig. 8 by the clear difference between the end plate thicknesses on the left and right sides in the illustration. The end plate 12 with the integrated flow guide section forming the flow guide body 16 can in particular comprise or consist of a foamed plastic material, in particular a polyurethane foam. The flow guide body 16 has a thickness in the radial direction that essentially corresponds to a pleat height of a filter medium body 10 designed as a filter bellows 10.

[0110] Advantageously, a filter element 1 according to the third embodiment can be manufactured without trimming the filter medium body 10 at the first end 101, which reduces the production effort.

[0111] Furthermore, the support grid 15 has a slit 151' in the region of the end section 151, which slit comprises a plurality of slits distributed over the circumference, which slits run in particular parallel to the longitudinal axis L. The slits can run substantially parallel to the longitudinal axis L. The slit 151' increases the deformability of the filter element 1 in the region of the first end 101, so that it can be elastically expanded radially under lower forces, which can improve the sealing performance provided by the radial sealing surface 143.

[0112] Figs. 9 and 10 show a fourth embodiment of the filter element 1 according to the invention. Since the filter element 1 according to the fourth embodiment is very similar to the filter element 1 of the third embodiment, only the differences will be discussed below. Otherwise, features disclosed with respect to the first, second, and / or third embodiment are transferable to the fourth embodiment and vice versa.

[0113] The filter element 1 of the fourth embodiment differs from the third embodiment in that the flow guide body 16 is formed by a thin-walled plastic component. Thin-walled means, in particular, that the flow guide body 16 has a thickness in the radial direction that corresponds to a fraction of the pleat height of a filter medium body 10 designed as a filter bellows 10. For example, a wall thickness of the flow guide body 16 is less than 1 / 5, preferably less than 1 / 10, of the pleat height of a filter medium body 10 designed as a filter bellows 10. The flow guide body 16 can be glued to the first end 101 of the filter medium body 10, for example.

[0114] The flow guide body 16 has, at its end facing the first end 101 of the filter medium body 10, a radially projecting collar that forms the end plate 12 open to the interior 11. At its end facing away from the first end 101 of the filter medium body 10, the flow guide body 16 has a radially projecting flange on which the sealing profile 142 with the circumferentially extending sealing surface(s) 141, 143 is arranged. The sealing profile 142 is, in particular, formed separately from the flow guide body 16 and comprises a softer material than the flow guide body 16. The flow guide body 16 can, in particular, comprise or consist of a hard plastic material, for example, polypropylene or a polyamide.The radially projecting flange has a wave-like profile with a circumferentially variable period and / or amplitude, which corresponds to the wave-like profile with a circumferentially variable period and / or amplitude of the circumferentially extending sealing surface(s) 141, 143. The radially projecting flange of the flow guide body 16 can have a groove-like cross-section into which the sealing profile 142 can be inserted as a separate part. Advantageously, the material used for the flow guide body 16 in the filter element 1 according to the fourth embodiment is less than in the third embodiment. The flow guide body 16 can be manufactured, for example, as an injection-molded part or a blow-molded part.

[0115] Figs. 11 to 13 show a fifth embodiment of the filter element 1 according to the invention, which differs significantly from the embodiments of Figs. 1 to 10. Nevertheless, there are similarities, which is why only the differences will be discussed below. Otherwise, features disclosed with respect to the first, second, third, and fourth embodiments are transferable to the fifth embodiment, and vice versa.

[0116] The first end 101 of the filter medium body 10 lies in a plane, namely a normal plane with respect to the longitudinal axis L, in which the end plate 12, which opens into the interior space 11, also runs. In particular, the filter medium body 10 has a constant height over its circumference.

[0117] The circumferentially extending sealing surface(s) 141, 143 or the sealing profile 142, in turn, has a wave-like profile with a variable period and amplitude in the circumferential direction. The circumferentially extending sealing surface(s) 141, 143 or the sealing profile 142 has a wave-like profile over its entire circumference, in particular with the period and / or amplitude being variable over the entire circumference (see Fig. 13). The wave-like profile of the sealing surface 141, 143 has a transverse wave-like and sine wave-like profile and / or is formed by a spline curve.

[0118] The circumferentially extending sealing surface 141, 143 has a radial distance DRU (see Fig. 12) from the longitudinal axis L which varies in the circumferential direction. In relation to the longitudinal axis L, the circumferentially extending sealing surface 141, 143 has a transverse wave-like shape whose “direction of vibration” runs in the normal direction, so that the circumferentially extending sealing surface 141, 143 has a radial position which varies over the circumference.

[0119] Fig. 12 shows a longitudinal section of the filter element according to the invention from Fig. 11, wherein the sectional plane runs through a longitudinal center plane. The radial distance between the circumferentially extending sealing surface 141, 143, in particular radial sealing surface 143, and the longitudinal axis L is marked DRL2 on a left-hand side in the figure and DRLI on a right-hand side in the figure. It can be seen that DRL2 > DRLI, since the distance DRU varies over the circumference, since the circumferentially extending sealing surface 141, 143 follows a (radial) wave shape.

[0120] This becomes even clearer in the plan view of Fig. 13: The wave-shaped course of the circumferentially extending sealing surface(s) 141, 143 has both a variable period and a variable amplitude over the circumference, resulting in a structure that is markedly rotationally asymmetrical with respect to the longitudinal axis L.

[0121] Due to the (radially) wave-like shape of the circumferential sealing surface(s) 141, 143, a distance DRS; between a surface enclosing the filter medium body (10), in particular a lateral surface, and the circumferential sealing surface(s) 141, 143 is variable over the circumference. This is illustrated in Fig. 13 by the two dimensions DRSI and DRS2, where DRSI < DRS2.

[0122] Fig. 14 and Fig. 15 show a sixth embodiment of the filter element 1 according to the invention, which represents a combination of the first embodiment (Figs. 1 to 4) with the fifth embodiment (Figs. 11 to 3). Otherwise, features disclosed with respect to the first, second, third, fourth, and fifth embodiments are transferable to the sixth embodiment and vice versa.

[0123] The circumferential sealing surface 141, 143 has a wave-like profile over its entire circumference, in particular, wherein the period and / or amplitude is variable over the entire circumference. The wave-like profile of the sealing surface 141, 143 has a transverse wave-like and sine wave-like profile and / or is formed by a spline curve.

[0124] The filter medium body 10 has, at the first end 101, a wave-shaped profile with respect to the axial direction, which has a period and / or amplitude that varies in the circumferential direction. In other words, the height of the filter medium body 10 is variable over the circumference. The wave-shaped profile of the filter medium body 10 at the first end 101 corresponds to the wave-shaped profile of the circumferentially extending sealing surface 141, 143. The wave-shaped profile of the filter medium body 10 at the first end 101 is formed by an axial trimming of the filter medium body 10. The end plate 12, which is open to the interior 11, follows the three-dimensional contour of the filter medium body 10 at the first end 101 provided by the trimming, which contributes to an economical use of material in the provision of the end plate 12.

[0125] The circumferentially extending sealing surface 141, 143 has an axial distance Dxi (see Fig. 15) that varies in the circumferential direction from a reference plane PR running in the normal direction to the longitudinal axis L. Relative to the longitudinal axis, the circumferentially extending sealing surface 141, 143 has a transverse wave-like profile whose "oscillation direction" runs in the axial direction, so that the circumferentially extending sealing surface 141, 143 has a variable axial position over the circumference.

[0126] This becomes even clearer in Fig. 4, which shows a schematic representation of an axial distance Dxi of the circumferentially extending sealing surface from the reference plane over the circumference in a developed view over the entire circumference of the sealing device 14 (0° to 360°). Although Fig. 4 shows the developed view for the filter element according to the first embodiment, it is identical to the developed view for the filter element according to the sixth embodiment. The wave-shaped profile, viewed over the circumference, has both a variable period and a variable amplitude and has four wave crests 144 and four wave troughs 145 distributed over the circumference.

[0127] Furthermore, the circumferentially extending sealing surface 141, 143 also has a radial distance DU (see Fig. 15) from the longitudinal axis L that varies in the circumferential direction.

[0128] In relation to the longitudinal axis L, the circumferentially extending sealing surface 141, 143 therefore additionally has a transverse wave-like profile, the “oscillation direction” of which runs in the normal direction, so that the circumferentially extending sealing surface 141, 143 additionally has a variable radial position over the circumference.

[0129] Fig. 15 shows a longitudinal section of the filter element according to the invention from Fig. 14, wherein the sectional plane runs through a longitudinal center plane. The reference plane PR runs in the normal direction to the longitudinal axis L and contains the first end 101 of the filter medium body 10 at a circumferential position which is cut on the left side in the figure. The axial distance between the circumferentially extending sealing surface 141, in particular axial sealing surface 141, and the reference plane P is marked Dxi on a left side in the figure and Dx2 on a right side in the figure. It can be seen that Dx2>Dxi, since the distance Dxi varies over the circumference because the circumferentially extending sealing surface 141, 143 follows an (axial) wave shape. The reference plane PR can in principle also be arranged at other positions, which merely results in a different offset of the values ​​of Dxi and Dx2.

[0130] Furthermore, the height of the filter medium body 10 is marked HBI on a left-hand side in the figure and HB2 on a right-hand side in the figure. It can be seen that HB2 > HBI because the distance Hßi varies over the circumference, since the first end 101 of the filter medium body has a wave-shaped profile when viewed over the circumference, which has a period and / or amplitude that is variable in the circumferential direction and corresponds to the wave-shaped profile of the circumferentially extending sealing surface 141, 143. The heights Hßi of the filter medium body 10 that vary over the circumference can be produced in particular by an axial trimming of the filter medium body 10.

[0131] In addition, the radial distance between the circumferentially extending sealing surface 141, 143, in particular radial sealing surface 143, and the longitudinal axis L is marked with DRL2 on a right-hand side in the figure and with DRLI on a left-hand side in the figure. It can be seen that DRL2 > DRLI because the distance DRU varies over the circumference, as the circumferentially extending sealing surface 141, 143 follows a (radial) wave shape. This becomes even clearer in the plan view in Fig. 13 (top view of the filter element according to the fifth embodiment, which is, however, identical to a plan view of the filter element according to the sixth embodiment): The wave-shaped course of the circumferentially extending sealing surface(s) 141, 143 has both a variable period and a variable amplitude over the circumference, resulting in a structure that is maximally rotationally asymmetrical with respect to the longitudinal axis L.Due to the (radially) wave-like shape of the circumferential sealing surface(s) 141, 143, a distance DRSI between a surface enclosing the filter medium body (10), in particular a lateral surface, and the circumferential sealing surface(s) 141, 143 is variable over the circumference. This is illustrated in Fig. 13 by the two dimensions DRSI and DRS2, where DRSI < DRS2.

[0132] The filter element 1 of the sixth embodiment is thus characterized by the fact that degrees of freedom in both the axial and radial directions are utilized to design a sealing line defined by the circumferentially extending sealing surface(s) 141, 143 in order to create a maximally asymmetrical sealing line. In addition to a forced angular orientation when installing the filter element in a corresponding filter housing, these degrees of freedom in determining the sealing line's course also allow for very flexible adaptation to interfering contours present in specific installation spaces.

[0133] 16 and 17 show a filter element 1 according to the invention in accordance with the seventh embodiment. Unlike the filter elements in accordance with the first to sixth embodiments (FIGS. 1 to 15), the filter element 1 in accordance with the seventh embodiment is a flat filter element. The filter element 1 comprises a filter medium body 10 formed as a flat filter bellows 10 made of a filter medium with a plurality of folds 100. Inflow-side fold edges of the flat filter bellows 10 are located on the upstream side 105 in an inflow plane 107, and downstream fold edges are located on the downstream side 106 in an outflow plane 108. The upstream side 105 and the downstream side 106 are spaced apart from one another along the longitudinal axis L, and the filter medium body 10 can be flowed through along the longitudinal axis L. However, the flat filter bellows 10 can also be flowed through in the opposite direction (arrow D upwards).

[0134] A circumferential sealing device 14 is arranged on an outer circumference of the filter medium body 10.

[0135] The filter medium body 10 is cuboid-shaped and has four side surfaces. Two of the side surfaces run parallel to each other and are located opposite each other.

[0136] The filter element 1 further comprises a frame device 17 that encloses the filter medium body 10 at its outer periphery, wherein the sealing device 14 is arranged on a side surface 171 of the frame device 17 facing away from the filter medium body 10. The sealing device 14 projects radially beyond the frame device 17.

[0137] The frame device 17 can comprise or consist of a plastic material, which can in particular be glued or injection-molded onto the filter medium body. The frame device 17 can, however, also be formed from a textile material, such as a spunbonded fabric, and comprise a side band 173 on each end edge of the flat filter bellows 10 and a head band 172 on each end fold of the flat filter bellows 10. The sealing device 14 comprises at least one circumferentially extending sealing surface 141, which can be an axial sealing surface. The circumferentially extending sealing surface 141 has an axial distance Dxi, which can be variable in the circumferential direction, from a reference plane PR running in the normal direction to the longitudinal axis L. The reference plane P coincides, as shown in Fig. 16, for example, with the inflow plane 107. At the distances Dxi and DX2 shown as examples in Fig. 16 and Fig. 17, D X 2 > Dxi.

[0138] Relative to the longitudinal axis, the circumferentially extending sealing surface 141 has a transverse wave-like shape, the “oscillation direction” of which runs in the axial direction, so that the circumferentially extending sealing surface 141 has a variable axial position over the circumference.

[0139] The circumferentially extending sealing surface 141 has a wave-like profile in at least a partial area of ​​the circumference, in which the period and / or amplitude is variable over the circumference. The wave-like profile of the circumferentially extending sealing surface 141 can be formed on at least one of the side surfaces of the flat filter bellows 10, preferably on at least two side surfaces, which can in particular be opposite one another.

[0140] The filter element 1 also has pleat stabilizing means 18 that 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 18 can, for example, be threads or yarn that are glued to the pleat tips of the filter bellows 10.

[0141] Fig. 18 to Fig. 20 show three possible wave-shaped courses of the sealing surface of the sealing device with a period and amplitude that is variable in the circumferential direction, wherein, with respect to the longitudinal axis L, the course has a transverse wave-like course whose “direction of oscillation” runs in the normal direction, so that the course has a radial distance from a central longitudinal axis (center of the base circle) that is variable over the circumference.

[0142] The wave-like course is shown starting from a base circle with a diameter of 20 units, where the base circle was superimposed with a sine wave-like course with a circumferentially variable period and amplitude, which can be described by the following general functional equation: (fe ■ x c ) ■ D(x)| where x is a circumference coordinate, a is a constant that modifies the amplitude, b is a constant that modifies the period, c is a constant that modifies a variability of the period over the circumference and

[0143] D(x) is a function of the circumferential coordinate, for example, a polynomial, a hyperbolic function, or a logarithmic function, which modifies the amplitude variability across the circumference. The exemplary curves were obtained by varying the above-mentioned parameters and clearly demonstrate that the wave-like course of the sealing line can be adapted extremely flexibly to any technical boundary conditions.

[0144] Reference symbol

[0145] I Filter element

[0146] 10 Filter medium body / filter bellows

[0147] 100 folds

[0148] 101 Frontal first end

[0149] 102 Frontal second end

[0150] 103 Outer surface

[0151] 104 Inner lateral surface

[0152] 105 Upstream side

[0153] 106 Downstream side

[0154] 107 Inflow plane

[0155] 108 Downstream level

[0156] II Interior

[0157] 12 end plate open to the interior

[0158] 13 additional end plates, especially closed end plates

[0159] 14 Sealing device

[0160] 141 Sealing surface

[0161] 142 Sealing profile

[0162] 143 Radial sealing surface

[0163] 144 wave trough

[0164] 145 Wellenberg

[0165] 15 support grids

[0166] 151 frontal section

[0167] 151 ' slitting

[0168] 16 flow guide bodies

[0169] 17 Frame setup

[0170] 171 side surface

[0171] 172 headband

[0172] 173 sideband

[0173] 18 wrinkle stabilizers

[0174] L Longitudinal axis

[0175] R Radial direction

[0176] D Flow direction

[0177] Dxi Axial distance

[0178] ÜRSi Radial distance from a surface enveloping the filter medium body

[0179] DRU Radial distance from the longitudinal axis

[0180] P Reference plane

[0181] Hßi Height of the filter medium body

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 - at least one filter medium body (10) with at least one filter medium, through which a fluid to be cleaned can flow from an upstream side (105) to a downstream side (106) in a flow direction (D), - and at least one sealing device (14) arranged on the filter medium body (10), - wherein the sealing device (14) has at least one circumferentially extending sealing surface (141), - and wherein the sealing surface (141) of the sealing device (14) has a wave-shaped profile in at least one circumferential section, characterized in that the wave-shaped profile has a period and / or amplitude variable in the circumferential direction.

2. Filter element (1) according to claim 1, wherein the circumferentially extending sealing surface (141) has a wave-shaped course over its entire circumference, in particular wherein the period and / or amplitude is variable over the entire circumference.

3. Filter element (1) according to claim 1 or 2, wherein the wave-shaped course - is designed as a transverse wave and / or - has a sine wave-like curve, a square wave-like curve, a triangular wave-like curve, a sawtooth wave-like curve or a curve formed by a spline curve.

4. Filter element (1) according to one of claims 1 to 3, wherein the filter medium body (10) is arranged around a longitudinal axis (L) and at least partially encloses an interior space (11), in particular wherein the filter medium body (10) can be flowed through in the radial direction (R) with respect to the longitudinal axis (L).

5. Filter element (1) according to claim 4, wherein - the filter medium body (10) has a frontal first end (101) and a frontal second end (102) opposite the frontal first end along the longitudinal axis (L), and - the filter element (1) has an end plate (12) open to the interior (11) at the first end (101) of the filter medium body (10) and a further end plate (13), in particular a closed end plate (13), at the opposite second end (102) of the filter medium body (10), and - wherein the sealing device (14) is arranged on the end plate (12) open to the interior space (11).

6. Filter element (1) according to claim 5, wherein the sealing device (14) comprises a circumferential sealing profile (142) which rises in the direction of the longitudinal axis (L) from the end plate (12) open to the interior (11) and which has the circumferentially extending sealing surface (141).

7. Filter element (1) according to claim 6, wherein the circumferential sealing profile (142) is in one piece with the end plate (12) open to the interior (11), in particular wherein the end plate (12) open to the interior (11) net end plate (12) together with the circumferential sealing profile (142) is formed onto the filter medium body (10), in particular foamed, cast, welded or glued.

8. Filter element (1) according to one of claims 4 to 7, wherein the filter medium body (10) has a hollow cylindrical shape, in particular with a circular, elliptical, oval or long oval cross-sectional shape.

9. Filter element (1) according to one of claims 5 to 8, wherein the filter medium body (10) at the first end (101) in at least one circumferential section has a wave-shaped course with respect to an axial direction defined by the longitudinal axis (L), which has a period and / or amplitude variable in the circumferential direction and corresponds to the wave-shaped course of the circumferentially extending sealing surface (141), in particular wherein the wave-shaped course of the filter medium body (10) at the first end (101) is formed by an axial trimming of the filter medium body (10).

10. Filter element (1) according to one of claims 5 to 8, wherein the first end (101) of the filter medium body (10) lies in a plane, in particular wherein the first end (101) lies in a normal plane with respect to the longitudinal axis (L) or extends at an acute angle to the normal plane, wherein a section extending at least partially circumferentially axially between the first end (101) of the filter medium body (10) and the circumferentially extending sealing surface (141) is bridged by an at least partially circumferential flow guide body (16) which is directly or indirectly connected to the first end (101) of the filter medium body (10).

11. Filter element (1) according to one of claims 4 to 10, wherein the filter medium body (10) has a round filter bellows made of a filter medium with a plurality of folds (100), the radially outer fold edges of which lie in an outer circumferential surface (103) and the radially inner fold edges of which lie in an inner circumferential surface (104).

12. Filter element (1) according to any preceding claim, wherein the circumferentially extending sealing surface (141) comprises at least one circumferential radial sealing surface (143), which is present in particular on an inner circumference of the sealing profile (142).

13. Filter element (1) according to one of claims 1 to 3, wherein the upstream side (105) and the downstream side (106) of the filter medium body (10) are spaced apart from one another along the longitudinal axis (L) and the filter medium body (10) can be flowed through along the longitudinal axis (L), wherein the sealing device (14) is arranged on or adjacent to an outer circumference of the filter medium body (10).

14. Filter element (1) according to claim 13, wherein the filter medium body (10) has a flat filter bellows made of a filter medium with a plurality of folds (100), the inflow-side fold edges of which are present on the upstream side (105), in particular in an inflow plane (107), and the outflow-side fold edges of which are present on the downstream side (106), in particular in an outflow plane (108).

15. Filter element (1) according to claim 13 or 14, wherein the filter medium body (10) has the shape of a prism, in particular a straight prism, in particular wherein the filter medium body (10) is at least partially cuboid-shaped.

16. Filter element (1) according to one of claims 13 to 15, comprising a frame device (17) which at least partially encloses the filter medium body (10) on its outer circumference, wherein the sealing device (14) is arranged on a side surface (171) of the frame device (17) facing away from the filter medium body (10), in particular wherein the sealing device (14) projects radially beyond the frame device (17).

17. Filter element (1) according to one of claims 13 to 16, wherein the sealing device (14) is arranged in the region of a circumferential outer edge of the filter medium body (10), in particular on the upstream (105) or downstream side (106) of the filter medium body (10), directly on the filter medium body (10).

18. Filter element (1) according to one of the preceding claims, wherein the circumferentially extending sealing surface (141) in the at least one circumferential section with a wave-shaped profile has an axial distance (Dxi) which is variable in the circumferential direction from a reference plane (PR) extending in the normal direction to the longitudinal axis (L).

19. Filter element (1) according to one of the preceding claims, wherein the circumferentially extending sealing surface (141) in the at least one circumferential section with a wave-shaped course has a radial distance (DRS) that is variable in the circumferential direction from a surface enveloping the filter medium body (10).

20. Filter element (1) according to one of the preceding claims, wherein the circumferentially extending sealing surface (141) in the at least one circumferential section with a wave-shaped course has a radial distance (DU) from the longitudinal axis (L) which is variable in the circumferential direction.

21. Filter element (1) according to one of the preceding claims, wherein the sealing device (14) with the at least one circumferential section with a wave-shaped course of the sealing surface (141) is rotationally asymmetrical.

22. Filter element (1) according to one of the preceding claims, wherein the wave-shaped course of the sealing surface (141) has at least two wave troughs (144) and / or wave crests (145), in particular at least three wave troughs (144) and / or wave crests (145), in particular at least four wave troughs (144) and / or wave crests (145).

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

24. Filter device according to claim 23, wherein the filter housing has at least one circumferential housing sealing surface against which the circumferentially extending sealing surface (141) of the filter element (1) rests, wherein the housing sealing surface has, in at least one circumferential section, a wave-shaped profile with a period and / or amplitude variable in the circumferential direction, which corresponds to the wave-shaped profile of the sealing surface (141) of the filter element (1).

Images