Filter element, filter device, vehicle, use and method

Abstract

The invention relates to a filter element (8), for example for a motor vehicle (1), in particular for an interior filter device (6), in which the filter element (8) can be fastened in a filter housing (7), in which two engagement elements (23a, 23b) on a side face (22) of a frame (10, 50) of the filter element (8) are disengaged from associated engagement mating elements (24a, 24b) of the filter housing (7) in the released state of the two engagement elements, the two engagement elements (23a, 23b) are arranged at a first distance (D1) from each other in the release state and at a second distance (D2), which differs from the first distance, in the locked state, and wherein the two engagement elements (23a, 23b) are arranged at a second distance (D2), which differs from the first distance, in the released state. Wherein one of the two engagement elements (23a, 23b) on the side surface (22) is connected to a rigid element (27a) connecting the two engagement elements (23a, 23b) by means of an elastic element (28b), and wherein the elastic element (28b) generates a restoring force (RK1) acting on the one of the two engagement elements (23a, 23b) in the event of a transition between the release state and the locking state.

Description

Technical Field

[0001] The present invention relates to a filter element, for example for a motor vehicle, in particular for an internal filtration device. Furthermore, the present invention relates to a filtration device and a vehicle having such a filtration device. Still additionally, the present invention relates to the use of a filter element. According to yet another aspect, the present invention relates to a method for attaching a filter element at or in a filter housing.

[0002] Although the present invention is applicable to any filter element and filtration device, the present invention and potential problems will be described hereinafter with respect to an internal filter of a motor vehicle.

[0003] Increased air pollution, especially in metropolitan areas, and the use of modern air conditioning devices make it necessary to purify the treated and air-conditioned air guided from the outside of the motor vehicle into the interior by means of a suitable filter. For example, it is conceivable to use particulate filters, odor filters or combinations thereof to filter or absorb aerosols, particulate matter and odors contained in ambient air.

[0004] To filter the air inside a motor vehicle, a folded or pleated filter material is usually used, for example, a filter nonwoven fabric forming a folded pack. For this purpose, an initially flat sheet of filter material is folded in a zigzag shape. The folded pack is held, for example, by lateral zones and top zones or another type of frame. Such a filter element can be fixed in a filter housing in a replaceable manner. The filtration device thus formed can be installed in the air conditioning device of a corresponding motor vehicle.

[0005] The replacement of the filter element should be carried out as easily as possible. At the same time, the filter element should be firmly fixed in the corresponding filter housing. This means that the filter element should not, for example, move out of its position in the filter housing due to vibrations or pressure pulses. Another objective may be that only certain filter elements suitable for the respective application can be inserted into the filter housing.

[0006] To achieve these objectives, it is generally known to provide suitable engagement elements and engagement element mating parts (or receiving means) for the filter element and the filter housing. In the fastened or installed state, these elements provide a form fit to hold the respective filter element in the associated filter housing. Examples of such engagement elements and engagement element mating parts can be, for example, screws with associated threads or clips with associated latches. Background Art

[0007] DE 10 2007 050 850 A1 describes an internal filter for a heating or air conditioning device of a motor vehicle.

[0008] WO 2015 / 086661 A1 discloses a filter element having a filter medium and a frame for fastening the filter medium at or in a filter receptacle. The frame includes at least one engagement element and at least one snap hook. At least one engagement element can be pivotally engaged with a receiving element of the filter receptacle to pivot the filter element relative to the filter receptacle about a pivot axis. At least one snap hook can be snapped into at least one latch in the filter receptacle to prevent pivoting of the filter element relative to the filter receptacle about the pivot axis at least in a first direction.

[0009] WO 2021 / 213869 A1 discloses an air filtration device for a motor vehicle having a housing with a receptacle for a filter element, wherein the filter element includes a frame at least partially surrounding a filter material of the filter element. Side walls of the frame are elastically deformable such that a distance between two protrusions arranged at the same side wall relative to each other can be reduced so that, when inserting the filter element, a respective second protrusion moves past an inwardly oriented guide flank and into an associated second guide end region. Summary of the Invention

[0010] According to a first aspect, there is provided a filter element for use in, for example, a motor vehicle, particularly for an internal filtration device. The filter element can be fastened at or in a filter housing, wherein the filter element includes: a filter medium body; a frame at least partially surrounding the filter medium body; two engagement elements arranged at a side of the frame, the two engagement elements extending away from the filter medium body and being respectively engageable with associated engagement element mating parts at the filter housing to attach the filter element at or in the filter housing; a rigid element force-conductively connecting the two engagement elements at the side, wherein the two engagement elements are configured to disengage from the associated engagement element mating parts in their released state and to engage with the associated engagement element mating parts in their locked state, wherein the two engagement elements are spaced apart by a first distance in the released state and by a second distance different from the first distance in the locked state, wherein a first engagement element of the two engagement elements at the side is connected to the rigid element by means of an elastic element, and wherein the elastic element exerts a restoring force on the first engagement element of the two engagement elements when the two engagement elements transition between the locked state and the released state.

[0011] The term "force-conductively connected" is understood herein to mean that the rigid element is capable of transmitting a reaction force opposite to the restoring force between the two engagement elements. In an embodiment, this is made possible by a rigid element having a one-piece or multi-piece construction.

[0012] Advantageously, in this embodiment, the frame or the filter medium body is not elastically deformed (although preferably this is not excluded) in order to mount the filter element at or in the filter housing. Instead, the corresponding elastic deformation ability is provided at least in part or specifically by means of an elastic element which is mechanically connected between the first engagement element of the engagement elements and the rigid element. Accordingly, when generating the restoring force, the force flow extends from the first engagement element of the engagement elements through the elastic element, through the rigid element, and then (optionally, via another elastic element or directly) into another engagement element. The first engagement element of the engagement elements is connected to the rigid element by means of the elastic element and is thus only indirectly connected to the rigid element. The other engagement element can be connected to the rigid element directly but also indirectly. In particular, it can also be provided that the two engagement elements are each connected to the frame (in any case, one engagement element is connected to the frame by means of the elastic element), where the frame is only partially reinforced by the rigid element such that, for example, a section of non-rigid frame material lies between the force introduction point of the corresponding engagement element at the side and the rigid element. However, when this section is designed to be short, it will, for example, only bend to a small extent and will accordingly not impair the function.

[0013] One or more engagement elements can currently be configured, for example, as studs, protrusions, pins, beads, etc. More than two engagement elements can be provided. In particular, two engagement elements can be provided at two respective sides of the frame. Accordingly, two or more engagement element pairs are also provided at the filter housing. In particular, one of the two engagement elements (but it can also be the other engagement element) can be designed as a latch, where the corresponding engagement element is then designed as a mating latch.

[0014] The locked state preferably corresponds to the installed state of the filter element (i.e., the filter element is fastened at or in the filter housing). Preferably, in the locked state, movement of the filter element relative to the filter housing is prevented in all six degrees of freedom. The engagement of the two engagement elements with the engagement element pair should be understood as their forming a form-fit with each other respectively.

[0015] The released state preferably corresponds to the state in which the engagement element has just left the engagement with the engagement element pair. In particular, in the released state, the restoring force can be maximum. In this context, "maximum" corresponds to an observation period during which the filter element and the filter housing are first separated from each other and at the end of which the filter element is fastened at or in the filter housing.

[0016] To convert from the locked state to the released state, it may be particularly necessary to apply manual force to the filter element, in particular to one or both of the two engaging elements. In this context, the manual force can be applied indirectly or directly to at least one of the engaging elements. Thus, during installation, on the one hand, an installation force oriented in the insertion direction can be applied to the filter element, which then converts the insertion section of the engaging element mating part associated with the relevant housing into a movement transverse to the insertion direction, the insertion section being implemented, for example, as an inclined plane in order to change the distance between the engaging elements relative to each other. On the other hand, in particular for disassembly, means can be provided at the filter element itself to facilitate the application of manual force to at least one engaging element or to improve the accessibility of the engaging element. For this purpose, for example, an operating lever, a zone or a tab connected to at least one of the engaging elements can be envisaged.

[0017] In other words, the rest state presented by the engaging element without an external force load corresponds to its locked state. Due to the restoring force generated by the elastic element, one or more engaging elements have a tendency to automatically return to the locked state when converting from the released state to the locked state.

[0018] The first distance can be greater than or less than the second distance. This depends on the corresponding design. According to an embodiment, the difference between the first distance and the second distance amounts to less than 20%, preferably less than 10%, and even more preferably less than 5% of the first distance. In particular, in an embodiment, the distance difference is just sufficient for at least the first engaging element of the two engaging elements to be guided through the corresponding engaging element mating part in order to disengage them from each other. For example, the distance difference between the first distance and the second distance can amount to less than 15 mm, less than 10 mm or less than 5 mm. For the transition between the locked state and the released state, the movement of the engaging elements can be quasi away from each other or quasi towards each other.

[0019] The first engaging element (and / or the second engaging element mentioned later) of the two engaging elements can be designed to pivot or (also only) move linearly when transitioning between the locked state and the released state.

[0020] The elastic element is in particular a spring and can be manufactured, for example, from plastic material and / or metal.

[0021] The engaging element mating part can be formed at a wall section of the filter housing. The filter housing can be constructed, for example, in the form of a frame, in particular a rectangular frame. The wall section can be a partial area of the relatively positioned sides of the frame. The filter housing can be manufactured, for example, from plastic material. In particular, the filter housing is manufactured as an injection-molded plastic part. Additionally or alternatively, the filter housing can also be partially or completely manufactured from metal, in particular sheet metal.

[0022] For example, in the case where the filter element has a circular or other cornerless shape, one side can be provided (precisely). However, it is also possible to provide multiple, in particular four sides. In particular, two sides can be positioned opposite each other. For example, two oppositely positioned sides can be provided, each of which includes two (or more) engagement elements. Thus, the engagement between the filter element and the filter housing can be provided at at least two sides.

[0023] The filter element includes, for example, a filter medium (currently also referred to as the "filter medium body") and one or more stabilizing elements, in particular lateral zones and / or top zones (also referred to as end face zones), which at least partially stabilize the filter medium in order to maintain its shape, in particular during the filtering operation. The stabilizing elements can in particular form a closed or open frame surrounding the filter medium, which is also integral.

[0024] The stabilizing elements can be connected to the filter medium by material fusion at the rim, in particular can be glued to the filter medium. For this purpose, the stabilizing elements can be heated and the filter medium can be pushed into the heated material. As an alternative, the stabilizing elements can be injection molded onto the filter medium. In addition, adhesives can be used as auxiliary materials. The stabilizing elements can be produced from the same material as the filter medium. The stabilizing elements can be made, for example, of PET (polyethylene terephthalate), glass fiber material, synthetic fiber material or another plastic material or plastic material mixture or from non-woven fabric. In particular, the stabilizing elements can be produced as injection molded plastic parts. The stabilizing elements can be hard or flexible (in particular, can also be fluffy).

[0025] The grammage of the lateral zone of the frame (which currently preferably provides the "side of the frame") can be, for example, from 100 to 500 g / m², preferably from 200 to 400 g / m². The grammage is determined according to DIN RN 29073-1 (non-woven fabric). The tensile strength of the lateral zone or side of the frame in the machine direction (length direction) can reach, for example, at least 100, preferably at least 200, and even more preferably at least 500 N / 50 mm. Transverse to the machine direction, the tensile strength can reach at least 20, preferably at least 100, and even more preferably at least 250 N / 50 mm. The tensile strength is determined according to DIN EN 29073-3.

[0026] Preferably, the value of the grammage and / or tensile strength (in the machine direction and / or transverse to the machine direction) of the lateral zone is less than that of the top zone, in particular, the lateral zone is more elastic than the top zone. This means that less force is required to bend or stretch the lateral zone by a predefined measure compared to the top zone.

[0027] The filter medium can be constructed in a folded configuration or in a corrugated shape. As a fold, for example, a zigzag fold or a W-fold is known. The filter medium can be embossed and subsequently folded at the embossed edges, thereby forming sharp folding edges. A correspondingly reshaped flat material filter sheet can be provided as the starting material. For example, the filter medium is a filter fabric, a laid filter, or a filter nonwoven fabric. In particular, the filter medium can be manufactured by a spunbond method or a meltblown method. In addition, the filter medium can be felted or needled. The filter medium can include natural fibers (such as cotton) or synthetic fibers such as polyester, polyphenylene sulfide, or polytetrafluoroethylene. The fibers can be oriented in the machine direction, inclined to the machine direction, and / or transverse to the machine direction during processing.

[0028] The filter medium can have a single layer or multiple layers. In addition, it can include adsorbents such as activated carbon. In addition, the filter medium can have an antibacterial effect and / or an anti-allergic effect. Zinc pyrithione or nano silver can be considered as antibacterial substances, for example; polyphenols can be considered as anti-allergic substances, for example.

[0029] The corresponding filter element is used to filter fluids, that is, gaseous and / or liquid media, such as air. Here, the gaseous medium or air also includes gas or air / solid mixtures and / or gas or air / liquid mixtures. For example, an air conditioning device can include this filter element.

[0030] In particular, an open filter medium can be designed to remove particles of test dust A4 according to ISO-12103-1 from an air stream at a filtration rate of 0.10 to 0.30 m / s. With respect to the filter medium surface area, the air permeability is greater than 3,000 l / m 2 s (determined at 200 Pa according to ISO 9237). The determination of the filtration parameters can be carried out, for example, in accordance with DIN 71460-1.

[0031] In particular, a highly separating filter medium can be designed to remove particles of test dust A2 according to ISO 12103-1 and NaCl aerosol particles according to DIN 71460-1 from an air stream at a filtration rate of 0.10 to 0.30 m / s. With respect to the filter medium surface area, the air permeability is greater than 600 l / m 2 s (determined at 200 Pa according to ISO 9237). The determination of the filtration parameters can be carried out, for example, in accordance with DIN 71460-1.

[0032] The filter element may include a seal that seals the raw side associated with the filter element relative to its clean side. The seal may be constructed as a single component together with one or more stabilizing elements of the filter element. As an alternative, the seal may be designed as an additional component. For example, the seal may be attached to the filter medium, attached to one or more stabilizing elements, attached to the filter element, or attached to the filter housing.

[0033] The filter element may be removably fixed in the filter housing. The engagement between the two engagement elements and the associated engagement element mating part is preferably releasable.

[0034] The filter element or a filtering device having the filter element may be used in passenger cars, trucks, construction machinery, ships, rail vehicles, aircraft, and is generally used in air conditioning technology, especially heating / air conditioning equipment, household appliances, fuel cells, or building technology. These motor vehicles or vehicles may be operated electrically and / or by means of fuel (especially gasoline or diesel). Regarding building technology, in particular, fixtures for air treatment can be envisaged.

[0035] According to an embodiment, the second engagement element of the two engagement elements is connected to the rigid element by means of a second elastic element, wherein when the two engagement elements transition between the locked state and the released state, the second elastic element generates a restoring force acting on the second engagement element of the two engagement elements.

[0036] In this variant, therefore, at least two elastic elements are provided such that each of the two engagement elements is movable relative to the rigid element.

[0037] According to an embodiment, the second engagement element of the two engagement elements is rigidly connected to the rigid element.

[0038] Thus, only the first engagement element is movable relative to the rigid element, while the second engagement element is rigidly (i.e., immovably) coupled to the rigid element. The rigid connection between the second engagement element and this rigid element can be implemented directly or indirectly. Currently, "directly" is understood as "without mechanically interposing additional elements or components".

[0039] According to an embodiment, the first elastic element and / or the second elastic element is designed to generate a restoring force due to its bending elastic deformation.

[0040] As an alternative, the elastic element may be constructed as an element that can be stretched / compressed deformed. In particular, the elastic element is constructed as a leaf spring, a helical spring, a flat spring, or a corrugated spring.

[0041] According to an embodiment, the rigid element is a bending-resistant element.

[0042] As an alternative, the anti-bending element can be an anti-tensile / anti-compressive element. For example, such an element includes carbon fiber or aramid fiber.

[0043] According to an embodiment, the tensile / compressive resistance or bending stiffness of the rigid element is greater than that of the first elastic element and / or the second elastic element, and / or greater than the tensile / compressive resistance or bending stiffness of the frame in the lateral region.

[0044] In this way, it is ensured that it is substantially the first elastic element and / or the second elastic element that provides the deformation for the conversion between the locked state and the released state.

[0045] According to an embodiment, the rigid element is a one-piece part of the frame and / or is implemented as a lateral zone of the frame.

[0046] In this way, a simple structure that can be efficiently produced is generated.

[0047] According to an embodiment, the rigid element is a separate part attached to the side of the frame, in particular welded or glued thereto.

[0048] Compared with one-piece manufacturing, this variant can have advantages in terms of materials technology.

[0049] According to an embodiment, the restoring force acting on the first engaging element of the two engaging elements and the restoring force acting on the second engaging element of the two engaging elements are oriented towards each other or opposite to each other.

[0050] In this way, the locking or latching of the engaging element and the engaging element mating part can be implemented in a simple manner. In particular, the two restoring forces can be coaxially aligned.

[0051] According to an embodiment, the two engaging elements are implemented mirror-symmetrically with respect to each other, wherein the corresponding symmetry axis is oriented along the flow direction.

[0052] In an embodiment, the filter element can be installed in the housing in different orientations in this way.

[0053] According to an embodiment, the first elastic element and / or the second elastic element is fastened to the rigid element and / or the frame, in particular glued or welded thereto, or is formed as a single piece with the rigid element and / or the frame, in particular by injection molding of a plastic material.

[0054] The fastening of the first elastic element and / or the second elastic element to the rigid element and / or the frame can be carried out indirectly or directly. In particular, the first joining element and / or the second joining element can also be attached, in particular glued or welded, to the first elastic element and / or the second elastic element, or can be formed integrally with the first or second elastic element (optionally including the rigid element and / or the frame), in particular by injection molding of plastic material. Furthermore, the second joining element (in the variant in which it is rigidly fastened to the rigid element) can be fastened to the rigid element and / or the frame, in particular glued or welded to it, or can be formed integrally with the rigid element and / or the frame, in particular by injection molding of plastic material.

[0055] According to an embodiment, the first elastic element and / or the second elastic element is fastened to the frame and / or the rigid element by means of a socket, wherein the first elastic element and / or the second elastic element is oriented along the flow direction or at an acute angle thereto, wherein preferably the first joining element and / or the second joining element of the two joining elements is provided at the end of the first elastic element and / or the second elastic element facing away from the socket, and wherein preferably the elastic element extends parallel to and is spaced apart from at least one side of the frame and / or the rigid element.

[0056] In this case, the elastic element can be implemented, for example, as a flexurally elastic arm. Such an arrangement can be produced in a simple manner, for example, by injection molding of plastic material.

[0057] According to an embodiment, the first elastic element and / or the second elastic element is rod-shaped, and / or the first joining element and / or the second joining element of the two joining elements has a cam shape.

[0058] In this way, a geometry that is easy to manufacture is provided.

[0059] According to an embodiment, the first elastic element and / or the second elastic element is configured in a zigzag shape, and / or the first joining element and / or the second joining element of the two joining elements has a triangular shape.

[0060] The design of the zigzag shape advantageously provides a long spring travel. The triangular shape provides a beneficial latching geometry.

[0061] According to an embodiment, the rigid element is designed as a flat part. Preferably, the zigzag-shaped elastic element extends in the plane of the flat part or only in the plane of the flat part. The zigzag-shaped elastic element can be arranged in a window in the flat part, and preferably the window can be closed by means of a cover plate.

[0062] In this way, the elastic element can be accommodated in a space-saving manner and, optionally, in a well-protected manner.

[0063] According to an embodiment, the side faces are oriented perpendicular to the flow direction, and / or the lateral zones of the frame include side faces.

[0064] The side faces are preferably positioned opposite the filter housing or the wall thereof having the mating portion of the engaging element.

[0065] According to a further embodiment, the frame includes at least two oppositely positioned side faces, wherein the engaging elements are respectively arranged at the at least two side faces and extend away from the main body of the filter medium, and can be engaged with the corresponding associated mating portions of the engaging elements at the filter housing to attach the filter element at or in the filter housing, wherein preferably, the engaging elements are constructed symmetrically with respect to each other mirror-image with respect to a symmetry axis positioned in the main extension plane of the filter medium body.

[0066] By means of the engaging elements at both sides, the filter element can be held particularly firmly.

[0067] According to a further aspect, there is provided a filtering device, in particular an internal filtering device, for a motor vehicle, for example. The filtering device includes the filter element and the filter housing as described above, the filter element being fastened at or in the filter housing, wherein the two engaging elements are engaged with the corresponding associated mating portions.

[0068] According to an embodiment, the mating portions of the engaging elements associated with the first engaging element and / or the second engaging element of the two engaging elements include an insertion section and a locking section, wherein the first engaging element and / or the second engaging element of the two engaging elements are configured to be guided through the insertion section of the associated mating portion and directed to the locking section of the associated mating portion when attaching the filter element at or in the filter housing, wherein a restoring force fixes the first engaging element and / or the second engaging element of the two engaging elements in the locking section to prevent detachment therefrom, wherein preferably, the insertion section is designed to counteract the restoring force in order to change the distance between the two engaging elements.

[0069] In this way, a simple fastening possibility of the filter element at the filter housing is provided. The insertion section can terminate at the rim of the side face, which corresponds to the original side or the clean side of the filter element, for example. The locking section can extend parallel to the rim of the side face, for example.

[0070] According to an embodiment, the insertion section is oriented along the flow direction or at an acute angle thereto. The locking section can be connected to the insertion section and / or can be angled with respect to it. The locking section and / or the insertion section can be designed as a groove.

[0071] The locking section and the insertion section can be connected to each other such that they form a continuous groove. The angle between the locking section and the insertion section can reach, for example, between 30 and 90°, preferably between 70 and 90°, and more preferably 90°.

[0072] According to an embodiment, the respective mating pairs of engagement elements each include a locking section, where the locking sections face away from each other or face each other, and / or are mirror-symmetrical about a symmetry axis in the flow direction.

[0073] When the locking sections face away from each other, a first distance between the two engagement elements is less than a second distance. In other words, the engagement elements move away from each other to produce a locked state, or move towards each other to produce a released state.

[0074] On the other hand, when the locking sections are oriented towards each other, the first distance between the two engagement elements is greater than the second distance. In other words, the engagement elements move towards each other to produce a locked state.

[0075] Preferably, the two insertion sections associated with the two locking sections are arranged parallel to each other.

[0076] According to an embodiment, the insertion section includes a section that acts as an inclined plane on the first engagement element and / or the second engagement element of the two engagement elements, where the locking section forms an undercut at the end of the inclined plane.

[0077] By means of this inclined plane, the first engagement element and / or the second engagement element can be simply converted into a locked state, because the inclined plane converts the insertion movement of the filter element, especially the axially oriented insertion movement, into a movement that changes the distance between the engagement elements.

[0078] According to an embodiment, the inclined plane is inclined with respect to the flow direction, and / or the undercut extends transversely to the flow direction.

[0079] In this way, a simple installation of the filter element in the filter housing is achieved.

[0080] According to an embodiment, one or all of the respective mating pairs of engagement elements include a V-shaped geometry forming the insertion section, where the insertion section widens at its tip, thereby forming two undercuts, and one of these undercuts forms the locking section.

[0081] In this variant, a filter element with engagement elements oriented in different directions can be advantageously used. This means that the corresponding filter housing can be used more flexibly.

[0082] In an embodiment, it can be specified that the filter element is held independently of the contact surface (other than the mating pairs of engagement elements) at the filter housing, in other words, "hangs freely" in the installation space or the filtration device.

[0083] In addition, the filtering device can be configured as a multi-stage filter system, in which additional filter elements are positioned at the aforementioned filter elements and are indirectly held by the aforementioned filter elements. In particular, it can be provided that the filter element according to the invention is indirectly sealed by an additional filter element, and in particular, the interaction between the filter element according to the invention and the filter housing generates an axially oriented sealing preload force, and this axially oriented sealing preload force is transmitted to the additional filter element by contact with the additional filter element. In this context, the additional filter element includes a housing interface, and the filter element according to the invention is sealed only indirectly with respect to the housing (i.e., via the additional filter element). The contact between the filter element according to the invention and the additional filter element can be implemented by interposing a seal, but can also be implemented without a seal.

[0084] According to a further aspect, a vehicle having a filtering device as described above is proposed.

[0085] According to still another aspect, a use of a filter element as described above in a filtering device as described above is provided, in which the two engaging elements are engaged with the associated engaging element mating parts.

[0086] According to still another aspect, a method for attaching a filter element to or in a filter housing is provided. In this context, the filter element includes a filter body and a frame extending at least partially circumferentially. The method includes the following steps:

[0087] a) Inserting the filter element into the filter housing, and

[0088] b) Engaging two engaging elements of the filter element with the associated engaging element mating parts of the filter housing, the two engaging elements being provided at the side of the frame of the filter element and being connected to each other in a force-transmitting manner by means of a rigid element at the side, the distance between the two engaging elements changing, and an elastic element connecting the first engaging element of the two engaging elements to the rigid element generating a restoring force on the first engaging element of these engaging elements when the distance changes.

[0089] According to an embodiment, the first engaging element and / or the second engaging element of these engaging elements are inserted along the (corresponding, as required) insertion section of the filter housing substantially along the flow direction before step b).

[0090] The features and advantages described in connection with the first aspect correspondingly apply to the other aforementioned aspects, and vice versa.

[0091] Currently, numbers such as "one" or "two" should not be construed as being limited to exactly "one" or exactly "two". On the contrary, more than "one" or "two" corresponding elements (e.g., engaging elements) may also be provided, as long as there is no contrary indication currently.

[0092] Other possible embodiments of the present invention also include combinations of features or method steps described above or below with respect to the embodiments and not explicitly mentioned. In this context, those skilled in the art will also add individual aspects as improvements or supplements to the corresponding basic forms of the present invention.

[0093] Other embodiments of the present invention are the subject matter of the dependent claims and the embodiments of the present invention described below. Hereinafter, the present invention will be explained in more detail with reference to the accompanying drawings by way of examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0094] Shown herein:

[0095] Figure 1 is a schematic illustration of a motor vehicle having a filtration device;

[0096] Figure 2 is Figure 1 a perspective illustration of the filtration device of , which includes a filter housing in which an internal filter is arranged;

[0097] Figure 3 is Figure 2 a perspective illustration of the internal filter of , which includes a frame and a filter medium;

[0098] Figure 4 is Figure 3 a perspective illustration of the filter medium of ;

[0099] Figures 5A to 5H are different views of an embodiment providing a pivotable engaging element;

[0100] Figure 6 is a variant of the filter housing;

[0101] Figures 7A to 7F are different views of an embodiment providing a linearly movable engaging element;

[0102] Figure 8A and Figure 8B is an embodiment of a frame having an engaging element;

[0103] Figures 9A to 9F are different configurations when using engaging elements that move away from each other to produce a locked state;

[0104] Figures 10A to 10E is Figures 9A to 9Fa configuration, but differing in that the joining elements move towards each other; and

[0105] Figure 11 is a flow chart of a method according to an embodiment;

[0106] Figure 12 is a longitudinal section of an embodiment of a multi-stage filter system according to the invention.

[0107] In the drawings, identical or functionally identical elements carry the same reference numerals if not indicated to the contrary. Detailed Description

[0108] Figure 1 shows a motor vehicle 1 having an air-conditioning device 2, which can be configured as a heating and air-conditioning device. The air-conditioning device sucks in ambient air 3 and guides filtered air 4 into the passenger compartment 5 of the motor vehicle 1. For this purpose, the air-conditioning device 2 includes Figure 2 the filter device 6 illustrated in

[0109] The filter device 6 includes a filter housing 7, in which an internal filter 8 (currently also referred to as "filter element") is arranged, in particular replaceably. The internal filter 8 is illustrated in more detail in Figure 3 . The internal filter 8 includes a filter medium 9 (currently also referred to as "filter medium body"), and a frame 10 ( Figure 3 ) is connected to the filter medium 9, in particular completely surrounding the filter medium 9. The frame 10 can include, for example, lateral zones 11, 12 and top zones 13, 14.

[0110] In Figure 4 the filter medium 9 is illustrated separately. The filter medium 9 is, for example, a filter nonwoven, a filter fabric, a laid filter or a filter felt, in particular a needle-punched felt. In particular, the filter medium 9 can be produced by a meltblown process. The filter medium 9 can include natural fibers (such as cotton) or synthetic fibers such as, for example, polyester, polyphenylene sulfide or polytetrafluoroethylene. The fibers can be oriented in the machine direction M, inclined to the machine direction M and / or transverse to the machine direction M during processing. Moreover, the fibers can be stretched in the spatial direction. The filter medium 9 can be designed as single-layer or multi-layer.

[0111] The filter medium 9 can include folds 15 that generally extend transversely to the machine direction M. The folded filter medium 9 is also referred to as pleats. The folds 15 can be produced by folding along a sharp folding edge 16 (also referred to as "folding tip") or by a corrugated configuration of the filter medium 9. The respective folds 15 can be defined by two folding segments 15a, which are interconnected by a corresponding folding edge 16. According to this embodiment, the folding edge 16 extends along Figure 2The inflow direction or flow direction orientation indicated by arrow L in the figure or the opposite orientation thereto. The folding can be carried out especially by means of a zigzag folding.

[0112] Moreover, it is possible to have a folding in which the folding portion 15 has a variable height H. In addition, the folding distance between the folding portions 15 can vary such that the distance A1 is different from the distance A2. The filter medium 9 can be designed to be self-supporting, i.e., if the flow is as expected during the filtration operation, the shape of the folding portion 15 is stable.

[0113] The filter medium 9 is bounded in the machine direction M by the end folding portions 17, 18. Transverse to the machine direction M, the filter medium 9 is bounded by the folding end face edges 19, 20 (also referred to as the folding profile). The term "folding end face edge" means the end face folding surface extending between the adjacent folding edges 16 of the respective folding portion 15.

[0114] The filter medium 9 can have a rectangular shape in a plan view (i.e., in the plane E of its flat extension). However, triangular, pentagonal or polygonal, circular or oval shapes are also conceivable.

[0115] Figure 3 The lateral zones 11, 12 illustrated in the figure are connected to the folding end face edges 19, 20, and the top zones 13, 14 are connected to the end folding portions 17, 18 especially by fusion, welding or gluing. The lateral zones 11, 12 and the top zones 13, 14 can form the frame 10 as a one-piece or multi-piece construction. The lateral zones 11, 12 and the top zones 13, 14 can be produced, for example, specifically from a flexible fiber material or especially produced as rigid injection-molded plastic parts. In particular, the frame 10 can be produced by injection molding onto the filter medium 9.

[0116] The filter medium 9 can act as a particle filter and, in this context, filter particles, especially dust, aerosols or liquid droplets, from the incoming air 3. Additionally, the filter medium 9 can act as an odor filter. For this purpose, it can include, for example, an activated carbon layer. The filter medium 9 can generally be configured to absorb or adsorb certain solid, liquid and / or gaseous substances.

[0117] During the filtration operation, as Figure 2 illustrated in the figure, the air L flows through the filter medium 9 perpendicular to the flat extension of the filter medium 9. In this context, the air L flows from the raw side RO of the inner filter 8 to the clean side RE.

[0118] To ensure sufficient sealing action between the raw side RO and the clean side RE, a seal can be provided between the internal filter 9 and the filter housing 7. This seal can, for example, be integrated in the frame 10. In this case, the frame 10 is at least partially formed of a sealing material. As an alternative, the seal can be provided as an additional part, for example, fastened to the frame 10, in particular injection molded onto the frame 10. In Figure 3 an example and details of such a seal 21 are illustrated.

[0119] Combined Figures 1 to 4 with the features described also apply to the embodiments according to Figure 5A explained below.

[0120] Figures 5A to 5H The first embodiment is shown. First, reference is made to Figure 5A and Figure 5B , which show the filter element 8 and the filter housing 7 in perspective and separated from each other (i.e., in the not-yet-installed state). It can be assembled into the Figure 5C filter device 6 shown in perspective, where the filter element 8 is detachably connected to the filter housing 7.

[0121] In Figure 5A , the lateral zone 11 of the frame 10 (here, for example, closed) is shown as having a side 22. The side 22 preferably faces a direction perpendicular to the flow direction L. Two engaging elements 23a, 23b project away from the side 22. This means that in the plan view of the filter element 8, the engaging elements 23a, 23b project outwardly away from the filter medium 9.

[0122] Preferably, two additional engaging elements are arranged at the sides of the relatively positioned lateral zones 12 (not visible in Figures 5A to 5C due to being hidden). It is possible to provide more than two engaging elements at one or both of the lateral zones 11, 12.

[0123] The engaging elements 23a, 23b can each be mated with the engaging element mating parts 24a, 24b ([[]] Figure 5B ) of the filter housing 7. This then corresponds to the installed state of the filter device 6, as Figure 5C illustrated. The reference lines of the reference numerals 24a, 24b are shown in dashed lines because they lead to the outside of the protrusions 25a, 25b (or projecting parts), thereby forming the engaging element mating parts 24a, 24b on their inner sides. The protrusions 25a, 25b are formed at the wall 26a of the filter housing 7. Instead of the protrusions 25a, 25b, it can be provided that the engaging element mating parts 24a, 24b are formed in the wall thickness of the wall 26a.

[0124] On the other hand, the engaging element mating parts 24c, 24d are clearly shown, which are provided to be relatively positioned with respect to the engaging element mating parts 24a, 24b at the wall 26b of the filter housing 7. The walls 26a, 26b can be part of the closed frame of the filter housing 7, and in the installed state, the frame completely surrounds the circumference of the filter element 8 and lies in the main extension plane H1 of the filter element 8.

[0125] In particular, the engaging elements 23a, 23b can be implemented symmetrically with respect to Figures 5A to 5C the engaging elements not shown in the figure, in particular with respect to the symmetry axis SY1, which is centrally arranged between the lateral zones 11, 12 and parallel to the lateral zones 11, 12, and also extends in the main extension plane H1 of the filter element 8. Alternatively or additionally, the engaging element mating parts 24a, 24b can also be implemented mirror-symmetrically with respect to the engaging element mating parts 24c, 24d about the axis SY2. The axis SY2 is centrally positioned between the walls 26a, 26b and parallel to the walls 26a, 26b, and also lies in the main extension plane H2 of the filter housing 7. However, asymmetric embodiments are also conceivable.

[0126] In an embodiment, for example, the filter housing 7 can include only the wall 26a. In this case, the filter element 8 can be fastened to one side of the filter housing 7 only by means of the engaging elements 23a, 23b and the engaging element mating parts 24a, 24b.

[0127] Figure 5D A exploded view of the Figure 5A shown filter element 8 is shown. The filter element 8 includes rigid elements 27a, 27b, here, the rigid elements 27a, 27b are implemented as separate parts and can be made of, for example, plastic material. According to this embodiment, the rigid elements 27a, 27b are implemented as elongated or rectangular flat parts. The rigid element 27a is fastened to the lateral zone 11, and the rigid element 27b is fastened to the lateral zone 12, for example, by welding or gluing thereto. In particular, the rigid elements 27a, 27b extend parallel to the corresponding lateral zones 11 or 12.

[0128] The rigid element 27a bears the engaging elements 23a, 23b, and the rigid element 27b bears the relatively positioned engaging elements 23c, 23d, and the engaging elements 23c, 23d are now partially visible here. As will be explained with the engaging element 23b representing other engaging elements, it includes, for example, a cam shape, but other profiles are also conceivable. The engaging element 23b is fastened at one end of the elastic element 28 (at the Figure 5D bottom in Figure 5DIn it, the top is connected to socket 29b. Socket 29b is in turn fastened to rigid element 27a. For example, elastic element 28b is implemented in the form of a flat spring. Engaging element 23b, elastic element 28b, socket 29b, and optionally rigid element 27a can in particular be produced as a one-piece component from a plastic material and, if desired, manufactured by injection molding.

[0129] Figure 5E shows Figure 5D view VE, and shows that elastic element 28b extends parallel to side 22 and is spaced apart from side 22 (compared with Figure 5D here side 22 has been added). In particular, elastic element 28b can extend parallel to flow direction L or at an acute angle to flow direction L.

[0130] As shown by means of Figure 5A the side view of Figure 5F illustrated, elastic element 28b effects pivoting of engaging element 23b about socket 29b, as illustrated by the double arrow, where the non-loaded initial position of engaging element 23b (which can correspond to the locked state) is illustrated by the solid line, while the disengaged pivoted position of engaging element 23b (corresponding to the released state) is illustrated by the dashed line. When pivoted to the disengaged pivoted position, elastic element 28b elastically deforms and thereby generates a restoring force RK1.

[0131] This also applies to engaging element 23a, which is also shown in Figure 5F and which is connected to socket 29a by means of elastic element 28a. Engaging element 23a can pivot contrary to engaging element 23b. When pivoted to the disengaged pivoted position indicated by the dashed line, engaging element 23a generates a restoring force RK2, which is directed contrary to restoring force RK1. According to this embodiment, engaging elements 23a, 23b or the corresponding cams face away from each other and are constructed mirror-symmetrically with respect to each other about axis SY3. Axis SY3 extends parallel to flow direction L and preferably divides lateral zone 11 into two halves of the same size.

[0132] The restoring forces RK1 and RK2 generate a force flow that extends from the engagement element 23b through the elastic element 28b, through the socket 29b, through the rigid element 27a into the socket 29b, into the elastic element 28a and into the engagement element 23a. The corresponding bending moments generated by the restoring forces RK1, RK2 are completely absorbed in the rigid element 27a. For this reason, in accordance with this embodiment, the rigid element 27a is a bending-resistant element. Accordingly, when the filter element 8 is installed in the housing 9, the lateral zone 11 does not bend or only bends slightly. In particular, for this purpose, the bending resistance of the rigid element 27a is greater than that of the corresponding elastic elements 28a, 28b and the lateral zone 11 (in other variants, additionally or alternatively, having a greater tensile stiffness / compressive strength). Here, the bending resistance means the bending resistance about an axis BA ( Figure 5A ) perpendicular to the side 22. For example, in particular by appropriate material selection, the elastic modulus of the rigid element 27a can be greater than the elastic moduli of the corresponding elastic elements 28a, 28b and the elastic modulus of the lateral zone 11.

[0133] The disengaged pivot positions of the engagement elements 23a, 23b illustrated by the dashed lines currently correspond to the released state. In the released state, the engagement elements 23a, 23b have a first distance D1 relative to each other. Figure 5G Shown Figure 5C section VG. Figure 5G Illustrates the locked state in which the engagement elements 23a, 23b are engaged with the respective associated engagement element mating parts 24a, 24b. In the locked state, the engagement elements 23a, 23b have a second distance D2 relative to each other. The distance D2 can be less than Figure 5F the distance D3 illustrated in or the same size as the distance D3. In the undeformed (unloaded) state of the elastic elements 28a, 28b, the engagement elements 23a, 23b have the distance D3. This undeformed state corresponds to the non-assembled state of the filter housing 7 and the filter element 8, i.e., when the filter housing 7 and the filter element 8 exist as separate parts. When the distance D2 is less than the distance D3, this means that the engagement elements 23a, 23b in the locked state rest on the engagement element mating parts 24a, 24b in a pre-tensioned manner.

[0134] Figure 5H Shown Figure 5B section VH. Hereinafter, the structure of the engagement element mating parts 24a, 24b will be explained in more detail with the aid of Figure 5G and Figure 5H As will be explained with the engagement element mating part 24b representing all the engagement element mating parts of this embodiment, each of them includes an insertion section 30b and a locking section 31b, and the insertion section 30b and the locking section 31b are formed as continuous grooves in the protrusion 25b ( Figure 5B ). AsFigure 5B As shown, the insertion section 30b opens towards the rim 33 of the frame 10 (at the Figure 5B top in Figure 5H ). The corresponding opening is identified at 34b. The insertion section 30b forms an inclined surface 32b (

[0135] ) which is inclined, for example, at an angle of 5 to 45 degrees relative to the flow direction L. Figure 5A and Figure 5B When the filter element 8 is installed in the filter housing 7, the filter element 8 (from above in Figure 5H ) is inserted into the filter housing 7. For this purpose, the engagement elements 23a to 23d are inserted into the respective associated openings 34a to 34d. The inclined surface 32b has the effect that the engagement element 23b pivots from its initial position to its disengaged pivot position and finally, at the end of the inclined surface 32b, snaps outwards into the undercut 35b of the locking section 31b ( Figure 5G ), as illustrated in

[0136] In the opposite direction, the engagement element 23a moves along the inclined surface 32a which is arranged symmetrically with respect to the inclined surface 32b about the symmetry axis SY4. The symmetry axis SY4 is arranged parallel to the flow direction L and preferably divides the wall 26a into two equal halves. At the end of the movement, the engagement element 23a snaps outwards into the undercut 35a. Here, "outwards" means that the engagement elements 23a, 23b for locking in the respective undercuts 35a, 35b move away from each other. Thus, the distance between the engagement elements 23a, 23b changes from an initial D3 to D1 and finally to D2 (where it is possible that D2 = DD3).

[0137] In a variant, in particular as illustrated in Figure 5H , the insertion section 30b and the locking section 31b are themselves symmetrically designed. This means that the inclined surface 32b has a further inclined surface 36b positioned opposite thereto such that the inclined surfaces 32b, 36b complement each other to form a V-shaped geometry. A further undercut 37b is positioned opposite the undercut 35b such that the V-shaped geometry at its tip widens again on both sides. This variant is advantageous because the filter element 8 can thus also be inserted into the filter housing 7 where the engagement elements 23a, 23b pivot away from each other to reach the disengaged pivot position, i.e., the distance D1 is greater than the distance D2 or D3.

[0138] On the other hand, Figure 6 show an embodiment in which the insertion section 30b and the locking section 31b are implemented asymmetrically in a view corresponding to Figure 5H . Inside (here, "inside" means the area between the two engaging element pairs 24a, 24b), the insertion section 30b and the locking section 31b are each defined by a straight wall 38b, but where the straight wall 38b is not necessary and can be designed in different ways.

[0139] Figures 7A to 7F Show a further embodiment. Here, the filter housing 7 corresponds, for example, to Figure 5B or Figure 6 the filter housing. There are differences in terms of the engaging elements 23a, 23b and their connection to the rigid element 27. Here, Figures 7A to 7D the view corresponds to Figures 5A to 5D those views. Figure 7E Corresponds to Figure 5G the view. Figure 7F Show an exploded view of the rigid element 27a.

[0140] Here, the engaging elements 23a, 23b are provided to be movable only linearly and in particular extend parallel to the length extension LE of the lateral zone 11 ( Figure 7A ) so as to adjust between the release state ( Figure 7F the distance D1 in) and the locked state ( Figure 7F and Figure 7E the distance D2 in).

[0141] In detail, it can be stipulated that the rigid element 27a is arranged in the recess 39 in the lateral zone 11 illustrated in Figure 7D . As an alternative, the rigid element 27a can also be glued to the lateral zone 11.

[0142] The rigid element 27a is constructed, for example, as a rectangular flat part and as Figure 7F, comprising a rigid section 40, which adjoins two frames 41a, 41b in the longitudinal direction LE. Each frame 41a, 41d defines a window 42a, 42b at the inner side. In this embodiment, the elastic elements 28a, 28b are implemented in a meandering shape and are supported at their first ends 43a, 43b at the frame elements 44a, 44b of the respective windows 42a, 42b, wherein the respective frame elements 44a, 44b face the rigid section 40. At their second ends, the respective elastic elements 28a, 28b carry the engagement elements 23a, 23b. The meandering shape of the construction extends in a space-saving manner only in the plane of the respective windows 42a, 42b or in the plane of the rigid element 27a and permits purely linear mobility of the respective engagement elements 23a, 23b. The respective engaging elements 23a, 23b include guide sections 46a, 46b which are guided in a linearly slidable manner in guide counterpart sections 47a, 47b in the respective viewing windows 42a, 42b. Away from the guide sections 46a, 46b, the respective engaging elements 23a, 23b include a pair of locking sections 31a, 31b ( Figure 7C ), for example, a triangular profile. The respective viewing windows 42a, 42b can be covered or covered by means of a cover plate 49a, 49b. This has the following purpose in particular: to accommodate the meandering-shaped elastic elements 28a, 28b in a protected manner. The cover plates 49a, 49b are each embodied with an opening 50a, 50b, which enables the engagement elements 23a, 23b to pass through when the cover plates 49a, 49b are mounted on the rigid element 27a.

[0143] The rigid section 40 , the frame 41 a , 41 b , the elastic elements 28 a , 28 b and the engagement elements 23 a , 23 b may be manufactured as a one-piece plastic component, in particular by injection molding.

[0144] Figure 8A An embodiment is shown in which the rigid, in particular resistant to bending element 27a is part of the lateral zone 11 (i.e. integrated in the lateral zone 11). For this purpose, the lateral zone 11 can be made of a rigid plastic material in any case in the section extending between the sockets 29a, 29b associated with the joining elements 23a, 23b. Alternatively or in addition, fibers (e.g. carbon fibers and / or aramid fibers) can be integrated into the material of the lateral zone 11 in order to increase its rigidity. In this variant, preferably, the frame 10 with the lateral zone 11 (including the rigid element 27a, the sockets 29a, 29b, the elastic elements 28a, 28b and the joining elements 23a, 23b) is injection molded to the filter medium 9.

[0145] As an alternative, an additional frame 50 may be provided, such asFigure 8B . The additional frame 50 comprises, for example, four frame elements 51a to 51d. The frame element 51a forms the rigid element 27a. In particular, the engaging elements 23a, 23b are attached to the side 22 of the frame. The filter medium 9 is connected to the additional frame 50 together with its frame 10. In particular, the additional frame 50 can be manufactured before this as a separate (e.g. plastic) part, in particular injection molded. Another option is that the frame 50 is directly injection molded onto the frame 10.

[0146] Figures 9A to 9F Different embodiments are illustrated and in this context include the embodiments that have been described. Figure 9A As shown, these embodiments have in common that the locking action is implemented by means of the locking sections 31a, 31b so that the distance between the engagement elements 23a, 23b increases when transitioning from the released state to the locked state, i.e., the second distance D2 (locked state) is greater than the first distance D1 (released state).

[0147] according to Figure 9B The engaging elements 23a, 23b are each provided in a pivotable manner and are coupled to the respectively associated socket 29a, 29b by means of a rigid element 27a formed as an additional component.

[0148] and Figure 9B In contrast, according to Figure 9C In an embodiment of the present invention, provision is made that the sockets 29a, 29b are each connected to the lateral zone 11 by means of a plate 52a, 52b, wherein the lateral zone 11 comprises the rigid element in an integrated manner.

[0149] In accordance with Figure 9D In the embodiment of Figure 9B In contrast to the embodiment of the present invention, the engagement element 23a is rigid and directly connected to the rigid element 27a, for example, manufactured in one piece with the rigid element 27a. This means that the engagement element 23a cannot be moved relative to the rigid element 27a or the lateral zone 11. The relative mobility with the engagement element 23b results from its pivotability due to its attachment at the socket 29b by means of the elastic element 28b. Figure 9E The rigid element 27a and the engaging elements 23a, 23b are shown in perspective in FIG. Figure 9E As can be seen in FIG. 2 , the engagement element 23 a is designed as a pile, one end of which is free and the other end of which is connected to the rigid element 27 a.

[0150] Figure 9F The diagram is relative to Figure 9D A variant in which the joining elements 23a, 23b are each connected to the lateral zone 11 by means of a plate 52a, 52b, wherein the lateral zone 11 comprises or forms the rigid element 27a in an integrated manner.

[0151] Figures 10A to 10E corresponding to Figures 9A to 9D and Figure 9F , wherein the difference is that the distance between the engaging elements 23a, 23b decreases when transitioning from the release state to the locked state, i.e., the second distance D2 (locked state) is less than the first distance D1 (release state). Correspondingly, the restoring forces RK1, RK2 are oriented towards each other.

[0152] Figure 11 A flowchart showing an embodiment of the method.

[0153] In step S1, the filter element 8 is inserted into the filter housing 7.

[0154] In step S2, the engaging elements 23a, 23b are engaged with the corresponding engaging element mating parts 24a, 24b, wherein at least the restoring force RK1 (see, for example, Figure 9D , by means of the elastic element 28b) or both restoring forces RK1, RK2 (see, for example, Figure 9B and Figure 5F , by means of the two elastic elements 28a, 28b) acts positively. The bending moment or tensile / compressive force generated by the restoring forces RK1, RK2 is absorbed in the rigid element 27a, such that the lateral zone 11 preferably does not bend or only bends slightly.

[0155] In Figure 12 , a longitudinal section of the multi-stage filtration device 6 according to the invention is illustrated. It includes a filter element 8 according to the invention and at least one additional filter element 81. In an embodiment, the multi-stage filter element 6 includes two or more additional filter elements 81, 82. The fluid flows sequentially through at least two filter elements 8, 81, 82, for example, in the flow direction L. At least one of the filter elements 8, 81, 82 may include a gas filtration medium including at least one adsorbent. Another filter element among the filter elements 8, 81, 82 may be a particulate filtration medium, in particular including a HEPA filtration medium. The multi-stage filtration device 6 is particularly suitable for serving as an intake air filter for a fuel cell system or a cabin air filter for a motor vehicle.

[0156] The filter element 8 according to the invention is held in the corresponding mating engagement elements of the filter housing 7 by means of its engagement elements 23a, 23b in the manner described herein. In an embodiment provided only by way of example, the mating engagement elements associated with the housing are provided at a first housing part 71, which provides a receiving part for the filter element 8 according to the invention. In addition, the first housing part 71 can also provide a receiving part for at least one further filter element 81, 82. In addition to the first housing part 71, which can in particular be a housing base, the filter housing 7 includes a second housing part 72, which can in particular be a housing cover.

[0157] The filter element 8 according to the invention is sealed indirectly with respect to the filter housing 7 only by means of further filter elements 81, in particular by means of further filter elements 81, 82. In this context, the frame 10 of the filter element 8 according to the invention rests in a tightly sealing manner against the second filter element 81, in particular against the frame of the second filter element 81. A seal 21 can be located therebetween, which can for example be held at the filter element 8 according to the invention or at the further filter element 81, or can be inserted loosely. The further filter element 81 in turn rests in a similarly tightly sealing manner against yet another filter element 82, which in turn rests (i.e., directly) against the filter housing 7 by means of a housing seal 21', in particular against the first housing part 71. In an embodiment not shown, the filter device 6 includes exactly two filter elements, the filter element 8 according to the invention and only one further filter element 81. In this case, there is a housing seal 21' between the further filter element 81 and the filter housing 7.

[0158] The seals 21, 21' can in particular be axial seals. The filter element 8 according to the invention can in particular be inserted into the housing 7 such that the seal 21 is pre-tensioned. The force course of the sealing force K is schematically indicated by an arrow. Starting from the engagement of the engagement elements 23a, 23b of the filter element 8 according to the invention, the force course of the sealing force K extends through the frame of the filter element 8 according to the invention, the seal 21 between the filter element 8 according to the invention and the further filter element 81, the frame of the further filter element 81, the seal between the further filter element 81 and yet another filter element, and the frame of the yet another filter element 82 into the housing seal 22, at which it finally acts as an effective sealing force for sealing the yet another filter element 82 with respect to the housing 7, such that all filter elements 8, 81, 82 are sealed indirectly with respect to the housing 7.

[0159] The housing includes a housing sealing surface 711 against which the housing seal 21' rests in a tightly sealing manner. The housing sealing surface 711 is in particular designed as an axial sealing surface.

[0160] Although the present invention has been explained in more detail by means of preferred embodiments, the present invention is not limited thereto, but can be modified in many ways.

[0161] Reference numerals

[0162] 1 Motor vehicle

[0163] 2 Air conditioning device

[0164] 3 Ambient air

[0165] 4 Air

[0166] 5 Passenger compartment

[0167] 6 Filtering device

[0168] 7 Filter housing

[0169] 71 First housing part

[0170] 711 Housing sealing surface

[0171] 72 Second housing part

[0172] 8 Internal filter / filter element

[0173] 81, 82 Further filter elements

[0174] 9 Filter medium / filter medium body

[0175] 10 Frame

[0176] 11 Lateral zone

[0177] 12 Lateral zone

[0178] 13 Top zone

[0179] 14 Top zone

[0180] 15 Fold

[0181] 15a Fold section

[0182] 16 Fold edge

[0183] 17 End fold

[0184] 18 End fold

[0185] 19 Fold end face edge

[0186] 20 Fold end face edge

[0187] 21 Seal

[0188] 21' housing seal

[0189] 22 side

[0190] 23a - 23d joining elements

[0191] 24a - 24d mating parts of the joining elements

[0192] 25a, 25b protrusions

[0193] 26a, 26b walls

[0194] 27a, 27b rigid elements

[0195] 28a, 28b elastic elements

[0196] 29a, 29b sockets

[0197] 30a, 30b insertion sections

[0198] 31a, 31b locking sections

[0199] 32a, 32b inclined planes

[0200] 33 rim

[0201] 34a - 34d openings

[0202] 35a, 35b undercuts

[0203] 36b inclined plane

[0204] 37b undercut

[0205] 38b wall

[0206] 39 recess

[0207] 40 rigid section

[0208] 41a, 41b frames

[0209] 42a, 42b windows

[0210] 43a, 43b ends of the elastic elements

[0211] 44a, 44b frame elements

[0212] 46a, 46b guiding sections

[0213] 47a, 47b guiding mating sections

[0214] 49a, 49b covers

[0215] 50 frame

[0216] Openings 50a, 50b

[0217] Frame elements 51a - 51d

[0218] Plates 52a, 52b

[0219] Distances A1, A2

[0220] Axis BA

[0221] Main extension planes H1, H2

[0222] Flow direction L

[0223] Length extension direction LE

[0224] Clean side / outflow side RE

[0225] Restoring forces RK1, RK2

[0226] Original side / inflow side RO

[0227] Steps S1, S2

[0228] Symmetry axes SY1 - SY4

[0229] Force process of the pre - tightening force of the seal K

Claims

1. A filter element (8), for example for a motor vehicle (1), in particular for an internal filtration device (6), wherein, The filter element (8) can be fastened to or in the filter housing (7), wherein the filter element (8) comprises: - a filter medium body (9), - a frame (10, 50) at least partially surrounding the filter medium body (9), - two engagement elements (23a, 23b) arranged at a side surface (22) of the frame (10, 50), the two engagement elements (23a, 23b) extending away from the filter medium body (9) and being capable of respectively engaging with associated engagement element mating parts (24a, 24b) at the filter housing (7) to fasten the filter element (8) to or in the filter housing (7), - a rigid element (27a) which connects the two engagement elements (23a, 23b) at the side surface (22) in a force - conducting manner, - wherein the two engagement elements (23a, 23b) are configured to disengage from the associated engagement element mating parts (24a, 24b) in their released state and to engage with the associated engagement element mating parts (24a, 24b) in their locked state, wherein the two engagement elements (23a, 23b) have a first distance (D1) relative to each other in the released state and a second distance (D2) different from the first distance in the locked state, - wherein at least a first engagement element (23b) of the two engagement elements (23a, 23b) at the side surface (22) is connected to the rigid element (27a) by means of an elastic element (28b), and wherein when the two engagement elements (23a, 23b) transition between the locked state and the released state, the elastic element (28b) generates a restoring force (RK1) acting on the first engagement element (23b) of the two engagement elements (23a, 23b).

2. The filter element according to claim 1, wherein, A second engagement element (23a) of the two engagement elements (23a, 23b) is connected to the rigid element (27a) by a second elastic element (28a), and wherein when the two engagement elements (23a, 23b) transition between the locked state and the released state, the second elastic element (28a) generates a restoring force (RK2) acting on the second engagement element (23a) of the two engagement elements (23a, 23b).

3. The filter element according to claim 1, wherein, The second engagement element (23a) of the two engagement elements (23a, 23b) is rigidly connected to the rigid element (27a).

4. The filter element according to any one of the preceding claims, wherein, The elastic element (28b) and / or the second elastic element (28a) are configured to generate restoring forces (RK1, RK2) due to their bending elastic deformation.

5. The filter element according to any one of the preceding claims, wherein, The rigid element (27a) is a bending - resistant element.

6. The filter element according to any one of the preceding claims, wherein, The tensile stiffness / compressive strength or bending stiffness of the rigid element (27a) is greater than that of the elastic element (28b) and / or the second elastic element (28a), and / or greater than the tensile stiffness / compressive strength or bending stiffness of the frame (10, 50) in the region of the side surface (22).

7. The filter element according to any one of the preceding claims, wherein, The rigid element (27a) is a one-piece part of the frame (10, 50) and / or is implemented as a lateral zone (11, 51a) of the frame (10, 50).

8. The filter element according to any one of the preceding claims, wherein, The rigid element (27a) is a separate part fastened at the side (22) of the frame (10, 50), in particular welded or glued thereto.

9. The filter element according to any one of claims 2-8, wherein The restoring force (RK1) acting on the first engaging element (23b) of the two engaging elements (23a, 23b) and the restoring force (RK2) acting on the second engaging element (23a) of the two engaging elements (23a, 23b) are oriented towards each other or in opposite directions to each other.

10. The filter element according to any one of the preceding claims, wherein, The two engaging elements (23a, 23b) are implemented symmetrically mirroring each other, wherein the corresponding symmetry axis (SY3) is oriented along the flow direction (L).

11. The filter element according to any one of the preceding claims, wherein, The elastic element (28b) and / or the second elastic element (28a) is fastened to the rigid element (27a) and / or the frame (10, 50), in particular glued or welded thereto, or is formed integrally with the rigid element (27a) and / or the frame (10, 50) by injection molding of plastic material, in particular.

12. The filter element according to any one of the preceding claims, wherein, The elastic element (28b) and / or the second elastic element (28a) is fastened to the frame (10, 50) and / or the rigid element (27a) by means of sockets (29a, 29b), wherein the elastic element (28b) and / or the second elastic element (28a) is oriented along the flow direction (L) or at an acute angle thereto, wherein preferably the first engaging element and / or the second engaging element of the two engaging elements (23a, 23b) is arranged at the end of the elastic element (28b) and / or the second elastic element (28a) facing away from the sockets (29a, 29b), and wherein preferably the elastic elements (28a, 28d) extend parallel to and are spaced apart from at least one side (22) of the frame (10, 50) and / or the rigid element (27a).

13. The filter element according to any one of the preceding claims, wherein, The elastic element (28b) and / or the second elastic element (28a) is rod-shaped, and / or the first engaging element and / or the second engaging element of the two engaging elements (23a, 23b) has a cam-shaped configuration.

14. The filter element according to any one of claims 1 to 12, wherein, The elastic element (28b) and / or the second elastic element (28a) has a zigzag shape, and / or the first engaging element and / or the second engaging element of the two engaging elements (23a, 23b) has a triangular shape.

15. The filter element according to any one of the preceding claims, wherein, The rigid element (27a) is implemented as a flat part, and / or the zigzag-shaped elastic elements (28a, 28b) extend in the plane of the flat part or only in the plane of the flat part and / or are arranged in windows (42a, 42b) in the flat part, wherein preferably the windows (42a, 42b) can be closed by means of cover plates (49a, 49b).

16. The filter element according to any one of the preceding claims, wherein, The side (22) faces perpendicular to the flow direction (L), and / or wherein, The lateral zones (11, 51a) of the frame (10, 50) include the side faces (22).

17. The filter element according to any one of the preceding claims, wherein, The frame (10, 50) includes at least two oppositely positioned side faces (22), wherein two engaging elements (23a - 23d) are respectively arranged at the at least two side faces (22), the two engaging elements (23a - 23d) extend away from the filter medium body (9), and are capable of engaging with corresponding associated engaging element mating parts (24a - 24d) at the filter housing (7) to fasten the filter element (8) at or in the filter housing (7), wherein preferably, the engaging elements (23a - 23d) are implemented mirror-symmetrically with respect to each other about a symmetry axis (SY1) located in the main extension plane (H1) of the filter medium body (9).

18. A filtering device (6), in particular an internal filtering device, for a motor vehicle (1) for example, comprising: A filter element (8) according to any one of claims 1 - 17, and A filter housing (7), the filter element (8) being fastened at or in the filter housing (7), wherein the two engaging elements (23a, 23b) engage with the associated engaging element mating parts (24a, 24b).

19. The filtering device according to claim 18, wherein The engaging element mating parts (24a, 24b) associated with the first engaging element and / or the second engaging element of the two engaging elements (23a, 23b) include insertion sections (30a, 30b) and locking sections (31a, 31b), wherein the first engaging element and / or the second engaging element of the two engaging elements (23a, 23b) is configured to be guided through the insertion sections (30a, 30b) of the associated engaging element mating parts (24a, 24b) and guided to the locking sections (31a, 31b) of the associated engaging element mating parts (24a, 24b) when fastening the filter element (8) at or in the filter housing (7), wherein restoring forces (RK1, RK2) fix the first engaging element and / or the second engaging element of the two engaging elements (23a, 23b) in the locking sections (31a, 31b) to prevent disengagement therefrom, wherein preferably, the insertion sections (30a, 30b) are configured to counteract the restoring forces (RK1, RK2) in order to change the distance (D1, D2) between the two engaging elements (23a, 23b).

20. The filtering device according to claim 19, wherein, The insertion sections (30a, 30b) are oriented along the flow direction (L) or at an acute angle thereto, and / or the locking sections (31a, 31b) are connected to and / or angled with respect to the insertion sections (30a, 30b), and / or wherein the insertion sections (30a, 30b) and / or the locking sections (31a, 31b) are configured as grooves.

21. The filtering device according to claim 19 or 20, wherein, The respective associated engagement element mating parts (24a, 24b) each include locking sections (31a, 31b), wherein the locking sections (31a, 31b) are oriented away from each other or towards each other and / or are mirror-symmetrical about a symmetry axis (SY4) in the flow direction (L).

22. The filtering device according to any one of claims 19-21, wherein, The insertion sections (30a, 30b) include sections that act as inclined planes (32a, 32b) on the first and / or second engagement elements of the two engagement elements (23a, 23b), wherein the locking sections (31a, 31b) form undercuts (35a, 35b) at the ends of the inclined planes (32a, 32b).

23. The filtering device according to claim 22, wherein, The inclined planes (32a, 32b) are inclined with respect to the flow direction (L), and / or the undercuts (35a, 35b) extend transversely to the flow direction (L).

24. The filtration device according to any one of claims 19-23, wherein, One or more of the respective associated engagement element mating parts (24a, 24b) include a V-shaped geometry forming the insertion sections (30a, 30b), which widen at their tips to form two undercuts (35b, 37b), wherein one of the undercuts (35b, 37b) forms the locking section (31a, 31b).

25. The filtration device according to any one of claims 18 - 24, comprising at least one further filtration element (81, 82), said further filtration element (81, 82) being arranged adjacent to the filtration element (8) in the flow direction (L), wherein, The fluid can flow, in particular sequentially, through the additional filter elements (81, 82) and the filter element (8), wherein the additional filter elements (81, 82) are held in the filter housing by the filter element (8), and wherein, in particular, the filter element (8) is indirectly sealed relative to the filter housing (7) by the additional filter elements (81, 82).

26. A vehicle (1) having a filtering device (6) according to any one of claims 18 - 25.

27. Use of a filter element (8) according to any one of claims 1 - 17 in a filtering device (6) according to any one of claims 18 - 25, wherein, Engage two engagement elements (23a, 23b) with the respective associated engagement element mating parts (24a, 24b).

28. A method for fastening a filter element (8) at or in a filter housing (7), wherein, The filter element (8) includes a filter body (9) and a frame (10, 50) that extends at least partially circumferentially, wherein the method includes: a) Inserting (S1) the filter element (8) into the filter housing (7), and b) Engaging (S2) two engagement elements (23a, 23b) of the filter element (8) with the respective associated engagement element mating parts (24a, 24b) of the filter housing (7), the two engagement elements (23a, 23b) being arranged at the sides (22) of the frame (10, 50) of the filter element (8) and being connected to each other in a force-transmitting manner by a rigid element (27a) at the sides (22), the distance (D1, D2) between the two engagement elements (23a, 23b) changing, wherein an elastic element (28b) connecting one of the two engagement elements (23a, 23b) to the rigid element (27a) exerts a restoring force (RK1) on the one engagement element (23a, 23b) when the distance (D1, D2) changes.

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