Air filter element arrangement and air filter

Abstract

Air filter element arrangement comprising an air filter element (200) and a functional component (300), wherein the air filter element (200) has an inlet surface (275), an outlet surface (285), and a filter medium (210), wherein the filter medium extends between the inlet surface and the outlet surface, wherein at least the outlet surface has a recessed area (500) in sections, wherein the functional component to be operatively associated with the air filter element projects at least partially into a free space resulting from the recessed area (500), wherein the functional component to be operatively associated with the air filter element is operatively associated with the recessed area of ​​the outlet surface, wherein the filter medium (210) is a filter medium folded from pleats (220), wherein the pleats each have a first pleat (230) and a second pleat (240), each with a pleat edge (231, 241;232, 242) abut each other at a fold edge (225), wherein the first fold leaves (230) of adjacent folds lie parallel to each other, wherein the first and second fold leaves (230, 240) extend between the inflow surface (275) and the outflow surface (285), characterized in that the offset (500) has an extension along an extension direction of the fold edges (225), that several folds (220) with variable fold depths (250) are made from a continuous media web, and that the functional component (300) is designed as a flow guide device (540) which projects at least partially into the free space resulting from the offset (500), wherein the flow guide device has at least one guide surface (541) whose guide surface edge (542) is directed towards the outflow surface (285) of the air filter element (200).

Description

Field of invention

[0001] The invention relates to the technical field of air treatment and filtration, for example, air filtration in a motor vehicle, construction machinery, or agricultural machinery. In particular, the invention relates to an air filter element arrangement and an air filter. Technical background of the invention

[0002] Air filters are used, for example, in the air supply of internal combustion engines to clean the air supplied for combustion of pollutants and dirt particles, so that only purified air is supplied to a combustion process in the internal combustion engine.

[0003] An air filter has an inlet opening for unfiltered raw air and an outlet opening for filtered clean air, as well as a filter element, which performs the actual filtering function. The engine draws in the required amount of air through the outlet opening of the air filter. The filter element consists of a filter medium, such as filter paper, through which the air to be filtered flows when the engine draws in air, so that the dirt particles are separated or separated from the flowing air in the filter medium.

[0004] Typically, the filter medium is pleated (pleated filter) or has a multitude of filter chambers (flute filter) to increase the surface area of ​​the filter, which also extends the service life of an air filter element, since a larger filter surface can capture more dirt particles before the pressure drop caused by the trapped dust in the filter medium has increased to such an extent that the air to the internal combustion engine is no longer allowed through in the required quantity or the air can no longer pass through or flow through the filter medium.

[0005] The filter element is typically housed within a casing, and this casing contains, for example, a functional component in the form of an additional filter element positioned in front of the air filter's outlet opening. The purpose of this additional filter element is to prevent unfiltered air from flowing through the air filter to the internal combustion engine, even when the air filter element is removed from the casing. Therefore, the air filter casing typically contains a main element (air filter element) and an additional functional component.

[0006] Furthermore, the housing's design can be adapted to external conditions, such as the available space in a vehicle's engine compartment. The housing's design directly influences the size of the air filter element and thus its filtration performance.

[0007] Depending on the volume within the air filter housing occupied by the functional component, the main element or air filter element is reduced in size accordingly, or the depth of the air filter pleats or filter chambers of the main element is adjusted so that the installation space within the air filter housing is divided.

[0008] Typically, the pleats of the air filter element are folded, or the depths of the filter chambers are designed, so that they are all the same depth, thus forming a cuboid-shaped air filter element. However, this can sometimes mean that the functional component does not occupy the entire installation space that is freed up inside the housing by the cuboid shape of the main element.

[0009] WO 98 / 47601 shows a filter element in the form of a pleated filter element for an air filter, wherein the filter element consists of a zigzag-shaped filter insert.

[0010] Utility model DE 20 2009 000 969 U1 discloses a filter element with a ring-shaped closed filter medium, wherein in a partial area the fold height between adjacent folds increases or decreases over several folds.

[0011] In DE 10 2010 036 540 A1 a filter arrangement with a main filter and a separate secondary filter is disclosed, wherein a filter holder is attached to the main filter and the secondary filter and configured to support them.

[0012] DE 10 2004 002 293 A1 describes a flat air filter with a through-opening in the filter element for passing an air line through it.

[0013] Further relevant state of the art is provided by DE 44 30 333 A1 and US 7 257 942 B2. Summary of the invention

[0014] It can be seen as an object of the invention to achieve high filter performance and a long service life of the air filter elements by increasing the filter area of ​​an air filter element, taking into account structural requirements for the air filter housing.

[0015] An air filter element arrangement according to the features of claim 1 and an air filter according to the features of claim 9 are specified. Further developments of the invention are described in the dependent claims and in the following description.

[0016] According to the invention, an air filter element arrangement is provided comprising an air filter element and a functional component, wherein the air filter element has an inlet surface, an outlet surface and a filter medium, wherein the filter medium extends between the inlet surface and the outlet surface, wherein at least the outlet surface has a recess, wherein the functional component projects at least partially into the free space resulting from the recess and wherein the functional component is in an operative relationship with the recess of the outlet surface of the air filter element.

[0017] The filter medium can consist of, for example, paper, non-woven fabric, microfibers, nanofibers or plastic, or be made of these materials or a mixture or composite of these materials.

[0018] A backset is an offset of a flow surface (inflow surface or outflow surface) in the direction of the opposite flow surface, whereby the backset remains part of the flow surface. A backset can be formed, in particular, by a kink, a step, or a bulge or recess; more specifically, the backset can be formed by the free volume or the concave indentation of a flow surface.

[0019] A functional component and the air filter element are considered to be in a functional relationship, for example, when these two components are coordinated for a filtration process, or when the filtration process only occurs through the combined action of these components. The functional component and the air filter element are also considered to be in a functional relationship when the functional component performs an additional function besides pure filtration, such as chemical filtration or airflow direction. In particular, the structural design of the functional component and the air filter element can be coordinated in such a way that their respective surfaces correlate, thus maximizing the utilization of the available installation space for both the air filter element and the functional component.

[0020] This allows a functional component to interact with an air filter element by arranging both components within an air filter housing and by designing the free space according to the dimensions of the functional component to minimize the loss of filter area of ​​the air filter element or to maximize the filter area despite the arrangement of a functional component in the air filter housing.

[0021] According to one embodiment of the invention, at least the outflow surface has a back offset with a one-dimensional concave or convex shape.

[0022] In particular, the air filter element can be easily formed from a single continuous media sheet, since the one-dimensional – as opposed to a two-dimensional – concave or convex shape can be created simply by varying the distance between the fold edges when folding the filter medium.

[0023] According to the invention, the filter medium is a filter medium folded from pleats, wherein the pleats each have a first pleat sheet and a second pleat sheet, each of which abut each other with a pleat sheet edge at a pleat edge, wherein the first pleat sheets of adjacent pleats are essentially parallel to each other, wherein the first and second pleat sheets extend between the upstream surface and the downstream surface, wherein the back offset has an extension along an extension direction of the pleat edges.

[0024] This allows the air filter element, as described above and below, to offer a large filter area and to be adapted to the structural conditions of the operating environment, since the offset allows for shaping the outer geometric form of the air filter element.

[0025] According to a further embodiment of the invention, the fold depth varies in a direction transverse to the direction of extension of the fold edges. In particular, the fold depth varies between adjacent folds.

[0026] The fold depth of a filter fold in one direction along the fold edge is constant.

[0027] According to a further embodiment of the invention, the air filter element has a support structure. In particular, the support structure also ensures lateral sealing of the pleats. Preferably, the support structure has a recess, especially in the form of an indentation, which corresponds at least partially to the recess of the outflow surface. Thus, the support structure has a corresponding recess or indentation at least along the recess, so that airflow into and out of the recess is minimally affected by the support structure.

[0028] According to a further embodiment of the invention, the pleated leaves are embedded laterally in the support structure at the edges that do not border the pleated leaf edges of adjacent filter leaves. This allows, in particular, an increase in the mechanical strength of the air filter element.

[0029] According to a further embodiment of the invention, the folds across the offset are made from a continuous layer of media. In contrast to an air filter element made from multiple layers of media, this results in no adhesive or joining seam, but rather the filter medium is made from a continuous material.

[0030] According to a further embodiment of the invention, adjacent pleated sheets are mutually stabilized by at least one spacer device. The spacer device can, in particular, be made of a plastic. For example, the molten plastic is applied to the filter medium to form the spacer device. Preferably, the spacer device has adhesive beads or glue beads. The spacer device, in particular the glue beads, is arranged on the downstream and / or upstream side of the filter medium.

[0031] The spacer device or glue beads can be arranged perpendicular or at an angle to the upstream or downstream surface. Furthermore, the glue beads or adhesive tracks can be continuous or interrupted / dotted and consist of several glue track segments. For example, the glue bead segments or adhesive track segments can be offset from each other such that the interrupted track forms an angle between 1° and 90° with the fold edges or the upstream or downstream surface.

[0032] The spacer device can, for example, ensure that the pleats maintain a specific distance from each other, or, in particular, that the opening angle of the filter pleats remains constant. This can support a consistently high filtration performance of the air filter element, as the pleat openings can only change to a minimal extent due to the adhesive beads.

[0033] In particular, the spacer device, especially in the form of adhesive beads, prevents the pleat openings from becoming too small. The pleats of a filter pleat can only move towards each other to a limited extent due to the spacer device positioned between them.

[0034] According to a further embodiment of the invention, the spacer device, in particular in the form of adhesive traces or glue beads, runs parallel to the pleated sheet edges of adjacent filter sheets that are not adjacent to the pleated sheet edges of each neighboring filter sheet.

[0035] This means that the spacer device runs, at least in sections, in one direction from the upstream surface to the downstream surface, or vice versa, and parallel to the support structure. In this way, it presents the lowest possible resistance to the airflow.

[0036] According to a further embodiment of the invention, the functional component has an interface surface, wherein the interface surface has at least a partial shape that corresponds to the offset of the outflow surface. This makes it possible, in particular, to adapt the functional component structurally or with regard to its shape to the air filter element. The surface of the functional component facing the air filter element is referred to as the interface surface.

[0037] According to a further embodiment of the invention, the support structure along the offset laterally covers the filter medium. In this way, the support structure seals or closes the filter medium at that surface of the air filter element which is perpendicular to the fold edges.

[0038] According to a further embodiment of the invention, the support structure has a first holding surface and a second holding surface, wherein the offset on the support structure is formed between the first holding surface and the second holding surface of the support structure.

[0039] This means that when inserted into an air filter housing, the first and second holding surfaces have a greater penetration depth than the offset on the support structure or the filter medium, and the air filter is thus held by the first and second holding surfaces.

[0040] The first and second holding surfaces can also be shaped almost identically or be point-like, i.e., have very small geometric dimensions less than 1 cm. 2 exhibit.

[0041] According to a further embodiment of the invention, the outflow area of ​​the filter medium associated with the recess on the support structure extends into a region lateral to the recess on the support structure. This region lateral to the recess on the support structure is, for example, the area between the first or second mounting surface and the maximum depth of the recess on the support structure, which is in the form of a recess. Because the outflow area extends into the region lateral to the recess on the support structure or the recess, the surface area of ​​the filter medium can be maximized despite the recess or recess.

[0042] According to a further embodiment of the invention, the support structure has a (third) retaining surface, which is arranged, for example, between the first and second retaining surfaces in the recess on the support structure. Thus, in addition to the first and second retaining surfaces, a further (third) retaining surface rests, for example, in the indentation on a retaining surface receptacle in an air filter housing and can ensure improved positioning and fixation of the air filter element in the air filter housing.

[0043] According to a further embodiment of the invention, at least one of the first, second, and third retaining surfaces absorbs a holding force in the direction along the extensional surface of the support structure. Thus, the retaining surface(s) ensure the positioning and / or fixing of the air filter element in an air filter housing. The retaining surfaces absorb a holding force along or parallel to the extensional surface of the support structure, particularly in a direction that runs in the direction of airflow through the air filter from the inlet surface to the outlet surface.

[0044] According to a further embodiment of the invention, the outflow surface associated with the back offset on the support structure has at least a section-wise one-dimensional concave or convex shape, wherein the curvature of the concave or convex shape corresponds at least section-wise to at least a part of the back offset.

[0045] The above statements regarding the one-dimensional concave or convex shape, which can enable an increase in the filter area, apply analogously to the one-dimensional concave or convex shape of the backset and the outflow and inflow surfaces.

[0046] The fact that the first fold sheet edges of adjacent folds are essentially parallel to each other means that the folds have an essentially the same direction of extension, which means that the direction of airflow through the folds is essentially the same.

[0047] According to a further embodiment of the invention, the outflow surface associated with the back offset has a shape corresponding to at least a part of the back offset of the support structure by providing several folds with varying fold depth.

[0048] According to the invention, at least some of the multiple pleats with varying pleat depths are made from a continuous filter media web. This eliminates the need to assemble several partial filters into an air filter element, and, due to the variable pleat depths relative to each other, a curved inlet or outlet surface can be provided, for example.

[0049] The offset allows for structural adjustments or adjustments regarding the geometric shape of the air filter housing, the air filter element, and the functional component.

[0050] According to one embodiment of the invention, the offset at the outflow surface has a one-dimensional concave or convex shape. In contrast, the functional component can have a convex or concave shape, so that the geometric shapes of the air filter element and the functional component are adapted to each other and the available installation space in an air filter housing is used to its maximum extent.

[0051] According to a further embodiment of the invention, the functional component has an interface surface, wherein the interface surface has at least a section of a shape that corresponds to the offset of the outflow surface. Similarly, the shape of the interface surface should be adapted to the offset to enable maximum utilization of the available space in the air filter housing.

[0052] According to the invention, the functional component is designed as a flow guide device which projects at least partially into the free space created by the recess, wherein the flow guide device has at least one guide surface whose guide surface edge is directed towards the outflow surface of the air filter element. The flow guide device can improve the outflow of air from the air filter.

[0053] According to a further embodiment of the invention, the functional component is designed as a flow straightener, wherein the flow straightener is associated with an air mass sensor to be brought into operative relationship with the air filter element, and wherein the flow straightener projects at least partially into the free space resulting from the offset.

[0054] The air filter element and the air filter, as described above and below, are primarily used for air filtration in motor vehicles, construction machinery, or agricultural machinery. Specifically, they are used to filter the intake air of an internal combustion engine or the supply air to a vehicle interior. However, they can also be modified to accommodate other fluids, particularly liquids and liquid mixtures. In particular, they can be largely identical in construction but designed as fuel or oil filter elements for motor vehicles, or as fuel or oil filters for motor vehicles.

[0055] The individual features can of course also be combined with each other, which can sometimes result in advantageous effects that go beyond the sum of the individual effects.

[0056] The following describes exemplary embodiments of the invention with reference to the figures. Brief description of the characters Fig. Figure 1 shows an isometric representation of an air filter element according to an embodiment of the invention. Fig. Figure 2 shows a side view of an air filter element according to an embodiment of the invention. Fig. Figure 3 shows a sectional view of an air filter according to an embodiment of the invention. Fig. Figure 4 shows a sectional view of an air filter element and a functional component according to a non-inventive embodiment of the invention. Fig. Figure 5A shows a cross-section of an air filter element according to an embodiment of the invention. Fig. Figure 5B shows a cross-section of an air filter element according to an embodiment of the invention. Fig. Figure 5C shows a cross-section of an air filter element according to an embodiment of the invention. Fig. Figure 5D shows a cross-section of an air filter element according to an embodiment of the invention. Fig. Figure 5E shows a cross-section of an air filter element according to an embodiment of the invention. Fig. Figure 5F shows a cross-section of an air filter element according to an embodiment of the invention. Fig. Figure 5G shows a cross-section of an air filter element according to an embodiment of the invention. Fig. Figure 6 shows a cross-section of a flute filter not according to the invention. Fig. Figure 7 shows an air filter element and a functional component according to an embodiment of the invention. Fig. Figure 8 shows an isometric exploded view of an air filter with air filter element, housing and functional component not according to the invention. Fig. Figure 8A shows an isometric representation of an air filter with air filter element, housing and functional component not according to the invention. Fig. Figure 9 shows a sectional view of an air filter according to a non-inventive embodiment of the invention. Fig. Figure 9A shows a sectional view of an air filter according to a non-inventive embodiment of the invention. Fig. Figure 9B shows a sectional view of an air filter according to a non-inventive embodiment of the invention. Fig. Figure 10 shows an isometric representation of an air filter according to an embodiment of the invention. Fig. Figure 10A shows an isometric representation of an air filter according to an embodiment of the invention. Fig. Figure 11A shows an isometric representation of an air filter element according to an embodiment of the invention. Fig. Figure 11B shows an isometric representation of a non-inventive functional component for an air filter. Fig. Figure 11C shows an isometric representation of a housing of an air filter according to an embodiment of the invention. Fig. Figure 12A shows an isometric representation of an air filter element according to an embodiment of the invention. Fig. Figure 12B shows an isometric representation of a functional component not according to the invention. Fig. Figure 13A shows an isometric representation of an air filter element. Fig. Figure 13B shows an isometric representation of an unclaimed functional component for an air filter. Fig. Figure 13C shows an isometric representation of a. Fig. Figure 13D shows an isometric representation of an air filter element. Fig. Figure 14 shows a sectional view of an air filter with main element, functional component and housing according to. an unclaimed embodiment. Fig. Figure 15 shows an isometric representation of an air filter not according to the invention. Fig. Figure 16 shows a sectional view of an isometric representation of an air filter according to Fig. 15. Fig. Figure 17 shows a cross-sectional view of an air filter according to... Fig. 15. Fig. Figure 18 shows an isometric representation of an air filter element of a filter according to Fig. 17. Fig. Figure 19 shows a sectional view of an isometric representation of an air filter according to an embodiment of the invention. Fig. Figure 20 shows a sectional view of an air filter not according to the invention. Fig. Figure 21 shows a sectional view of an air filter not according to the invention. Fig. Figure 22 shows a side view of an air filter not according to the invention. Fig. Figure 23 shows an isometric representation of an air filter element not according to the invention. Fig. Figure 24 shows an isometric representation of an air filter. Fig. Figure 25 shows a sectional view of an isometric representation of an air filter made of Fig. 24. Fig. Figure 26 shows an isometric representation of an air filter element of a filter made of Fig. 25. Fig. Figure 27 shows a front view of an air filter not according to the invention. Fig. Figure 28 shows a cutaway view of an air filter made of Fig. 27. Fig. Figure 29 shows a sectional view of an isometric representation of an air filter made of Fig. 27. Fig. Figure 30 shows an isometric representation of an air filter element. Fig. Figure 31 shows a sectional view of an air filter according to an embodiment of the invention. Fig. Figure 32 shows a sectional view of an isometric view of an air filter according to an embodiment of the invention. Fig. Figure 33 shows a sectional view of an isometric view of an air filter element according to an embodiment of the invention. Fig. Figure 34 shows a side view of an air filter not according to the invention. Fig. Figure 35 shows a sectional view of an isometric representation of an air filter according to Fig. 34. Fig. Figure 36 shows a side view of an air filter according to an embodiment compatible with the present invention. Fig. Figure 37 shows a sectional view of an isometric representation of an air filter according to Fig. 36. Fig. Figure 38 shows an isometric representation of an air filter element of an air filter according to. Fig. 37. Fig. Figure 39 shows a side view of an air filter. Fig. Figure 40 shows a sectional view of an isometric representation of an air filter. Fig. Figure 41 shows an isometric representation of an air filter element. Fig. Figure 42 shows an isometric representation of an air filter with housing cover, air filter element and housing body according to an embodiment of the invention. Fig. Figure 43 shows an isometric representation of an additional filter element for an air filter according to [reference]. Fig. 42.

[0057] The representations in the figures are schematic and not to scale. Detailed description of implementation examples

[0058] If the same reference numbers are used in the following figure description, they refer to the same or similar elements.

[0059] Fig. Figure 1 shows an air filter element 200, or a main element 200 of an air filter. The air filter element 200 has a plurality of filter pleats 220, each filter pleat 220 being formed by a first pleat 230 and a second pleat 240. The filter pleats 220, or the first pleats 230 and the second pleats 240, extend in one direction from the inflow direction 270 to the outflow direction 280, and vice versa. The pleat edge 225 of each filter pleat 220 runs perpendicular to the inflow direction 270 or outflow direction 280. The pleat edge 225 represents the transition from a first pleat to a second pleat and is formed on both the inflow surface 275 and the outflow surface 285 of the air filter element 200.

[0060] The fold edge 225 is formed on the upstream side or upstream surface 275 by an upstream fold edge 231 of the first fold 230 and by an upstream fold edge 241 of the second fold 240. Similarly, a fold edge 225 on the downstream surface 285 is formed by an downstream fold edge 232 of the first fold 230 and an downstream fold edge 242 of the second fold 240.

[0061] A pleated sheet edge 260, i.e. the upstream pleated sheet edge 231 or the downstream pleated sheet edge 232 of the first pleated sheet 230 or the upstream pleated sheet edge 241 or the downstream pleated sheet edge 242 of the second pleated sheet 240, is formed by a pleated sheet meeting the filter fold with the pleated sheet edge, i.e. that the pleated edges of two pleated sheets form the filter fold 220.

[0062] From the inflow surface 275 to the outflow surface 285 run a lateral fold edge 233 of the first fold sheet 230 and a lateral fold edge 243 of the second fold sheet 240.

[0063] The filtering effect of the air filter element 220 is achieved by using a filter medium to form the filter pleats 220 and by allowing uncleaned air, so-called raw air, to flow in the direction of flow 270 onto the inlet surface 275 and through the filter medium in the direction of flow 280 towards the outlet surface 285, where it is cleaned, so that clean air is present on the outlet surface 285.

[0064] The fold edges 225 of all filter folds 220 on the upstream surface 275 or on the downstream surface 285 form a so-called envelope 265, wherein one envelope 265 can in particular be an enveloping surface of the fold edges on the upstream surface or on the downstream surface.

[0065] The fold edges 225 also define the upstream surface and the downstream surface, with the envelope corresponding to that of these two surfaces which spatially encloses or surrounds a functional component.

[0066] This is a connecting line of the fold edges 225 at the outflow surface 285 or at the inflow surface 275, wherein the connecting line runs perpendicular to the fold edges and the connecting line forms a one-dimensional concave surface or shape with the outflow surface or inflow surface.

[0067] A one-dimensional concave surface exhibits curvature in only one direction. This curvature of the one-dimensional concave surface in one direction arises, for example, from the fact that the fold depths of adjacent filter folds decrease or increase continuously, so that the fold edges 225 have a variable distance to the respective opposite surface, i.e., the inflow surface 275 or the outflow surface 285. The envelope 265 and the fold edges 225 thus form a one-dimensionally curved concave surface, since the one-dimensional concave surface is curved in the direction of the envelope 265, but has no curvature in the direction of the fold edges 225.

[0068] In the folds, glue beads 235 extend in one direction from the upstream surface to the downstream surface and ensure increased stability of the filter medium.

[0069] Fig. Figure 2 shows a side view of an air filter element 200 with a plurality of filter pleats 220. The envelope 265 at the outflow surface 285 is formed by the fact that the pleat edge 225 of each filter pleat 220 has a different distance to the inflow surface 275. The so-called pleat depth 250 decreases or increases continuously in the direction of the envelope 265, depending on the viewing direction. Of course, adjacent filter pleats can also have the same pleat depth 250.

[0070] In other embodiments, the envelope 265 can also be designed such that the pleat depth of adjacent filter pleats initially decreases and then increases again. In general, the envelope 265 can assume any desired shape and be designed such that an inlet area 275 or an outlet area 285 of the air filter element 200 corresponds to or is adapted to the external conditions by the design of an air filter or an air filter housing.

[0071] As shown in Fig. As can be seen from Figure 2, the raw air flows in the direction of inflow 270 onto the inflow surface 275, then penetrates the filter pleats 220, distributes itself along the air flow direction 610 so that the air on the inflow side passes through the first pleat 230 and the second pleat 240 of each filter pleat 220 and is thereby filtered, so that the filtered air in the outflow direction 280 emerges from the air filter element 200 on the outflow surface 285, the air on the outflow side of the air filter element 200 being referred to as clean air.

[0072] Fig. Figure 3 shows a sectional view of an air filter 100, wherein the air filter 100 has a housing body 110 and a housing cover 120, which together form the housing of the air filter.

[0073] Inside the housing are an air filter element 200 and a functional component 300, both arranged to filter the air flowing through them. The air filter element 200 is located in the housing body 110 and is held in place by two retaining surfaces 190, which also fix the position of the air filter element 200 within the housing body 110. The air filter element 200 also has a seal 205, which ensures at least a sealing connection between the housing body 110 and the air filter element. Additionally, the seal 205 can provide a seal between the housing body 110 and the housing cover 120, or between the air filter element 200 and the housing cover 120. The seal 205 can be located on or attached to the air filter element 200, the housing body 110, or the housing cover 120.

[0074] The essential function of the seal 205 is to allow unfiltered air to pass the air filter element 200 and reach the clean air connection 140. It should also largely seal the housing of the air filter 100. This means that air enters the housing of the air filter 100 through the raw air connection 130 or through the first inlet opening 130, passes through the air filter element 200 and the functional component 300, and exits the housing of the air filter 100 as filtered clean air at the clean air connection 140 or at the outlet opening 140 of the air filter 100.

[0075] The seal 205 is provided between the housing body 110, the housing cover 120 and the air filter element 200, so that no unfiltered air can enter the housing of the air filter in such a way that it can leave the housing at the clean air connection 140 without having flowed through and been cleaned by the filter medium of the air filter element 200.

[0076] The housing body 110 has an air filter element receptacle 150 into which a so-called filter collar 207 can engage. The filter collar 207 is designed to mechanically fix the air filter element 200 to the housing body.

[0077] The airflow of the air to be cleaned or filtered in the Fig. The air filter 100 shown in Figure 3 runs over or through the raw air connection 130, the air filter element 200, the functional component 300 and the clean air connection 140. The air is essentially cleaned by the air filter element 200, leaves it at the outflow surface 285 and then leaves the housing of the air filter 100 via the functional component 300.

[0078] Fig. Figure 4 shows a sectional view of an unclaimed embodiment of a main element 200 or an air filter element 200 and a functional component 300 in the form of a star-pleated additional filter element 310 along the section line AA. Fig. 3. In particular, the Fig. 4 shows that the functional component 300 is adapted to the envelope 265 of the air filter element 200.

[0079] Both the main element 200 and the functional component in the form of an additional filter element 310 have filter pleats 200 with variable pleat depth, the pleat depth of the respective filter pleats being coordinated so that the envelope 265 of the outflow surface 285 of the air filter element 200 corresponds to the envelope 265 of the inflow surface 301 of the functional component 300 or the inflow surface 311 of the additional filter element 310.

[0080] The airflow through the main element 200 and the functional component 300 proceeds in such a way that the air to be cleaned enters the main element 200 on the inlet surface 275, then exits the main element 200 on the outlet surface 285 and subsequently enters the additional filter element 310 on the inlet surface 311 and exits it on the outlet surface 312.

[0081] Fig. Figure 5A shows a cross-sectional representation of an air filter element 200, wherein the outflow surface 285 has a semicircular free volume, which semicircular free volume only excludes a part of the outflow surface 285 and the semicircular free volume is formed by the envelope 265.

[0082] Fig. Figure 5B shows the cross-section of an air filter element 200, wherein the outflow surface 285 has a sawtooth cross-section. The sawtooth cross-section extends over the entire width of the air filter element 200. The enclosing edge 265 connects the fold edges 225 of the filter pleats of the filter medium 210.

[0083] It should be noted in particular that the number of filter folds is not determined or influenced by the shape and dimensions of the cross-section of the outflow surface 285, i.e. the course of the envelope 265.

[0084] Just like in Fig. As shown in Figure 5B, the air filter element 200 can have a plurality of filter pleats in all embodiments described above and below, wherein the filter pleats or the number of filter pleats are not predetermined or determined by the course or the cross-section of the envelope 265.

[0085] Fig. Figure 5C shows an elliptical or semicircular shape of the envelope 265 of the outflow surface 285 of the air filter element 200. The semicircular or elliptical shape of the envelope 265 extends over the entire width of the air filter element 200 or over the entire width of the outflow surface 285.

[0086] Fig. Figure 5D shows an air filter element 200 whose outflow surface 285 is shaped such that the filter pleat depth decreases or increases continuously in one direction of the envelope 265. The envelope 265 of the pleat edges on the outflow surface can be a hyperbola, resulting in a concave shape for the outflow surface 285. However, the envelope can also be linear, meaning it has no curvature and is therefore a straight line.

[0087] Fig. Figure 5E shows an air filter element 200, whose outflow surface 285 is stepped, the steps of the outflow surface 285 being connected to each other via a semicircular course of the envelope 265.

[0088] Fig. Figure 5F shows an air filter element 200 whose outflow surface 285 is trapezoidal, such that the filter pleat depth of the central filter pleats 220 is greater than the pleat depth of those filter pleats at the edge of the cross-sectional representation. The envelope 265 of the outflow surface can be linear or curved in the areas of increasing pleat depth from the edges towards the center of the air filter element 200.

[0089] Fig. Figure 5G shows an air filter element 200, whose inflow surface 275 has a stepped profile, and whose outflow surface 285 has a region of linearly decreasing fold depth and a region of constant fold depth. Thus, the envelope has a trapezoidal profile, which can be either symmetrical or asymmetrical.

[0090] As from the Fig. 5F and Fig. As can be seen in 5G, the inflow surface 275 and the outflow surface 285 can have any shape or envelope of the fold edges.

[0091] Likewise, the profiles of the inflow surface 275 and the outflow surface 285 can be as shown in the Fig. 5A to 5G are shown to be used in flute filters.

[0092] In the Fig. The cross-sections of the air filter element 200 shown in Figures 5A to 5G and the contours of the envelope 265 are exemplary and non-exhaustive lists of the possible shapes of the envelope 265. Rather, any desired contour of the envelope 265 on the inlet surface 275 or on the outlet surface 285, or on both, the outlet surface 285 and the inlet surface 275, can be achieved by varying the fold depth of the filter pleats.

[0093] The Fig. 5A to 5G each show the free volume or free volumes 500 as a hatched area, the free volumes being designed in such a way that they represent the spatial difference to a cuboid air filter element starting from one of the air filter elements as described above and below.

[0094] Fig. Figure 6 shows a side view of an unclaimed flute filter element 600, wherein the outflow surface 285 runs along the envelope 265 such that the filter chambers 605 have different filter chamber depths.

[0095] The flute filter element 600 is characterized by the fact that the filter chambers 605 are alternately open and closed on the inlet surface 275 and on the outlet surface 285. Thus, the airflow direction 610 through the flute filter element 600 is such that the incoming air enters those filter chambers 605 on the inlet surface 275 which are open in the direction of the inlet surface 275, then passes through the filter medium 210 into the adjacent filter chambers 605 which are closed on the inlet surface and open on the outlet surface 285, where the air exits the flute filter element 600.

[0096] The inflow area 275 of a flute filter element is formed by the inflow-side openings of the filter chambers and analogously the outflow area 285 is formed by the outflow-side openings of the filter chambers.

[0097] The filter chambers 605 of the flute filter element 600 are characterized in the in Fig. The representation shown in 6 is characterized in particular by the fact that they have a different filter chamber depth in one direction from the inflow surface 275 to the outflow surface 285.

[0098] Fig. Figure 7 shows an air filter element 200 which is functionally related to the functional component 300 in such a way that the air filter element 200 is shaped on the outflow surface 285 such that at least a part of the air filter element 200 presses or fixes the filter collar 207 of the functional component 300 along a pressure direction 305.

[0099] This makes it possible, for example, to ensure that the functional component is held in position within the housing of the air filter, or even to position it in the first place.

[0100] The envelope of the outflow surface 285 of the air filter element 200 and the envelope of the inflow surface 301 of the functional component 300 are each shaped such that they have a corresponding or analogous profile. This ensures, in particular, that the volume or space of the air filter housing is used efficiently and that the main element 200 and the functional component 300 or the additional filter element 310 have the largest possible filter area, i.e., the largest possible surface area of ​​the filter medium.

[0101] Fig. Figure 8 shows an isometric view of an air filter element 200, a functional component 300 not designed according to the invention and a housing body 110 of an air filter.

[0102] The air filter element 200 has a circumferential filter collar 207, which engages in the air filter element receptacle 150 of the housing body 110 when the air filter element is inserted into the housing body. The air filter element receptacle 150 also engages in the recess 294 of the support element. A seal 205 is attached to the filter collar 207, i.e., to the air filter element, along the filter collar, so that the seal 205 seals the housing body 110 against the housing body 110 when the air filter element 200 is inserted.

[0103] The air filter element 200 has a filter medium 210, which filter medium is folded in such a way that a free volume 500 is formed in the direction of the functional component 300 at the outflow surface of the air filter element, wherein the free volume 500 is surrounded by the envelope 265.

[0104] A support element 290 or support structure 290 with a recess 294 extends perpendicular to the pleat edges 225 of the filter medium 210. Its purpose is twofold: firstly, to seal the filter pleats at their lateral openings, preventing unfiltered air from passing laterally around or flowing past the filter pleats; secondly, to stabilize the air filter element 200 and the filter medium 210; and thirdly, to position and secure the air filter element 200 during and after its insertion into the housing 110.

[0105] The air filter element 200 is positioned by the retaining surface 190 of the housing projection 194, the retaining surface 190 being adapted to the contour of the enveloping edge 265 of the air filter element 200 or the recess 294. Thus, when the air filter element 200 is inserted into the housing body 110, the retaining surface 190 engages in the recess 294 of the support element 290 and positions and secures the air filter element in the housing body.

[0106] The retaining surface receptacle 190 can, for example, be arranged on the housing projection 194, wherein the housing projection can represent a recess in the housing body wall from the outside to the inside, so that this recess engages in the free volume 500 or in the indentation 294.

[0107] Furthermore, the support element 290 has a first holding surface 291, a second holding surface 292 and a third holding surface 296, wherein the first holding surface 291 is designed to be received by a holding surface receptacle 191 in the housing body 110, wherein the second holding surface 292 is designed to be received by a holding surface receptacle 192 and wherein the third holding surface 296 is designed to be received by a holding surface receptacle 196 in the housing body.

[0108] Thus, the air filter element 200 rests on the retaining surfaces 291, 292 on the retaining surface receptacles 191, 192 in the housing body 110 in an inserted state of the air filter element in the housing body.

[0109] The functional component 300, which is not designed according to the invention, is in the form of a circular cylinder and projects from the outlet opening 140 into the interior of the housing body 110. An axial direction of the functional component 300 extends parallel to the outflow direction at the outflow surface 285 of the air filter element 200 and parallel to an axial direction of the outlet opening 140. Furthermore, the outflow direction at the outflow surface 285 of the air filter element 200 is parallel to, or at least at an acute angle to, an axial direction of the outlet opening 140. In other words, the axial direction of the functional component extends in the direction of the filter edges of the outflow surface of the main element 200. In other words, the outlet opening 140 on the housing body 110 is thus located opposite the outflow surface 285 of the air filter element 200.This means that a main airflow direction between air filter element 200 and outlet opening 140 does not change and is maintained when the air flows over the outflow surface through the outlet opening.

[0110] In order to create space for the functional component inside the housing body when the air filter element 200 is inserted, the air filter element has a free volume of 500.

[0111] Fig. Figure 8A shows an air filter element 200, a functional component 300 not designed according to the invention, and a housing body 110. The functional component is a cylinder with a circular base, the axial direction of which extends parallel to the course of the filter edges of the outflow surface 285.

[0112] The outlet opening 140 is located on a wall of the housing body 110, so that the airflow starting from the outflow surface 285 must be deflected in order to pass through the outlet opening 140.

[0113] Fig. Figure 9 shows a sectional view of a housing body 110 with an air filter element 200 and a functional component 300, as shown in Fig. Figure 8 shows the functional component and the air filter element being inserted into the housing body.

[0114] The functional component 300 is sealed onto the outlet opening 140. This means that air exiting the air filter element 200 at the outflow surface 285 must flow through the functional component in order to exit the housing body via the outlet opening 140.

[0115] The air filter element 200 is sealed to the housing body 110 via the seal 205 and the filter pleats 220 have a respective pleat depth such that the filter pleats surround the functional component 300.

[0116] It should be noted in particular that the fold edges, or each fold edge individually, do not have a curved profile, i.e., that the fold edges run perpendicularly in one direction into or out of the drawing plane.

[0117] Fig. Figure 9A shows a sectional view of a housing body 110 with an air filter element 200 and a functional component 300, as shown in Fig. 8A shows the functional component and the air filter element being inserted into the housing body.

[0118] The functional component extends into the free volume 500 of the air filter element, parallel to the filter edge profile of the outflow surface 285, i.e. in a direction out of or into the plane of the drawing.

[0119] Fig. 9B shows a cross-sectional view of the section line AA from Fig. 9A.

[0120] As can be clearly seen, the functional component extends within the free volume 500. The functional component can have any extent within the free volume 500, whereby the greatest possible utilization of the spatial volume of the free volume 500 by the functional component is accompanied by an increased surface area of ​​the functional component, for example a filter area of ​​an additional filter element, which can improve the overall functional performance of the functional component or additional filter element.

[0121] Fig. Figure 10 shows an isometric view of a housing body with an inserted air filter element 200. The air filter element 200 has two support elements 290, each arranged laterally on the air filter element 200 and perpendicular to the fold edges 225 of the inlet surface 275. Naturally, the fold edges of the outlet surface also run perpendicular to the support elements 290.

[0122] Fig. 10A shows analogous to Fig. 10 an isometric view of the housing body with inserted air filter element 200 from the Fig. 8A, Fig. 9A and Fig. 9B. It can be seen that the outlet opening 140 is arranged on a wall of the housing body 110, which runs perpendicular to the filter pleat pattern on the inflow surface 275 and correspondingly on the outflow surface 285. The free volume 500 in the air filter element 200 utilizes the volume available in the housing body 110 in such a way that both the functional component 300 and the main element 200 are arranged within the housing body, and a maximum filter area of ​​the filter medium is achieved in the main element.

[0123] Fig. Figure 11A shows an isometric view of an air filter element 200, wherein the support element 290 has a profile according to the envelope 265 at the outflow surface 285.

[0124] Fig. Figure 11B shows a non-inventive functional component 300, which corresponds to the course of the envelope 265 of the air filter element 200. Fig. 11A corresponds.

[0125] Fig. Figure 11C shows a housing body 110, which is made up of the functional component 300 and the air filter element 200. Fig. to include 11B or 11A.

[0126] The housing body 110 has a plurality of closure elements 115 for closing a housing cover to the housing body. Furthermore, the housing body 110 has an outlet opening or a clean air connection 140.

[0127] Due to the sawtooth-shaped surface of the functional component 300 made of Fig. 11B and the corresponding course of the envelope 265 of the outflow surface 285 of the air filter element 200 from Fig. 11A enables the functional component 300 to have an increased surface area and thus improved filter performance compared to a flat functional component, while still making more efficient use of the volume available within the housing body 110.

[0128] Fig. Figure 12A shows an air filter element 200 with a support structure 290.

[0129] The support structure 290 extends along the envelope 265 at the outflow surface 285. Furthermore, the support structure 290 has a first retaining surface 291 and a second retaining surface 292, with the recess 294 located between the first retaining surface 291 and the second retaining surface 292. The recess 294 essentially corresponds to the course of the envelope 265 and the free volume 500 of the air filter element. The first retaining surface and the second retaining surface are designed to fix or position the air filter element 200 with the housing body of the air filter via the support structure 290.

[0130] Due to vibrations of the filter medium of the air filter element 200 during the filtration process, contact between the filter medium and the housing of the air filter must be avoided, as this could damage the filter medium. Therefore, the first retaining surface 291 and the second retaining surface 292 serve to position the air filter element 200 without the filter medium coming into contact with the housing.

[0131] Fig. Figure 12B shows a non-inventive functional component 300, which corresponds to the course of the envelope 265 of the air filter element 200. Fig. 12A corresponds.

[0132] Fig. Figure 13A shows an isometric representation of an air filter element 200. The support element 290 extends along a surface 293, which is spanned by the vectors 293x and 293y.

[0133] Thus, the extent surface 293 of a support structure 290 is such that the fold edges of the inflow surface 275 and the outflow surface 285 run perpendicular to the extent surface 293 of the support elements 290 of an air filter element 200.

[0134] The envelope 265 of the outflow surface 285 corresponds to a course of the indentations 294 on the support element 290. Like the first retaining surface 291 and the second retaining surface 292, the indentations 294 serve to fix and position the air filter element within the housing body.

[0135] Fig. Figure 13B shows a non-inventive functional component 300, which follows the contour of the envelope 265 of the outflow surface 285 of the air filter element 200. Fig. 13A corresponds to this.

[0136] Fig. Figure 13C shows an air filter element 200, where the outflow surface 285 extends as a plane between the support elements 290. The filter edges of the air filter element run along a plane on the outflow surface 285, meaning that the fold depth of all folds of the air filter element is the same.

[0137] The fold depth or the position of the fold edges on the outflow surface 285 and the outflow surface 285 itself are arranged such that the outflow surface 285, with all its associated fold edges, is offset in one direction relative to the inflow surface 275, starting from the first retaining surface 291 and the second retaining surface 292, as well as the indentations 294. This means that the retaining surfaces 291, 292, and the indentations 294 extend from the outflow surface 285 in the direction of the flow, which points away from the outflow surface. This allows the retaining surfaces 291, 292 to project deeper into the housing of an air filter than the filter medium or the fold edges of the outflow surface 285.

[0138] The outflow surface 285 can be arranged such that the fold edges of the filter medium located on it are positioned exactly at the level of the indentations 294.

[0139] Fig. Figure 13D shows an air filter element 200 analogous to the air filter element 200 in Fig. 13C, wherein in Fig. 13D the outflow surface 285 is not arranged at the level of the indentations 294, but has a certain distance from the indentation.

[0140] Thus, when the air filter element 200 is inserted into a housing body, not only the retaining surfaces 291, 292 protrude deeper into the housing body than the outflow surface 285, but also part of the support elements 290.

[0141] The Fig. 13C and Fig. Figure 13D shows a structure of an air filter element in which the outflow surface 285 is located closer to the inflow surface 275 than the holding surfaces 291, 292 and the indentations 294, or in which the inflow surface 285 is located in a flow direction of the air through the air filter element 200 between the inflow surface 275 and the holding surfaces 291, 292 and the indentations 294.

[0142] It should be noted that the distance of the outflow surface 285 from the holding surfaces 291, 292 and the indentations 294 of the support elements can be variable and can be adapted, for example, to the conditions and structural requirements within the housing body.

[0143] Fig. Figure 14 shows a sectional view of an air filter 100 not according to the invention. The housing 105 has the housing cover 120 and the housing body 110, wherein the housing body and the housing cover are fixed to each other by means of locking elements 115, which are closed, and a seal 205 seals the housing between the housing body and the housing cover.

[0144] Inside the housing body is the main element 200, or air filter element 200, whose outflow surface has the shape of the enveloping surface 265 and corresponds to the shape of the functional component 300. The functional component 300 is connected to the housing body 110 by means of the filter collar 207.

[0145] The air that has flowed through the air filter element 200 and the functional component 300 leaves the air filter 100 through the outlet opening 140.

[0146] Fig. Figure 15 shows an isometric view of an air filter 100 not according to the invention, wherein the air filter comprises a housing body 110, a housing cover 120, and closing elements 115 for closing the housing body with the housing cover. A first inlet opening 130 is arranged on the housing cover 120, and an outlet opening 140 is arranged on the housing body 110. The raw air flows through the inlet opening 130 into the air filter or the housing, is filtered in the air filter, and leaves the air filter through the outlet opening or the clean air connection 140.

[0147] Fig. Figure 16 shows a sectional view of an isometric representation of the air filter 100. Fig. 15. The air filter element 200 is arranged inside the housing body 110, wherein the air to be filtered passes through the air filter element 200 from the direction of the inlet opening 130 and leaves the housing body through the outlet opening or the clean air connection 140.

[0148] The air filter element 200 has a free volume 500 in the area of ​​the outlet opening 140. In the area of ​​the free volume 500, the folded edges 225 on the outflow surface 285 of the air filter element 200 form an envelope and thus a free volume of the air filter element. The profile of the air filter element, or rather the course of the envelope on the outflow surface, is adapted to the position and outflow direction of the clean air connection 140 so that no impact edge or strong deflection of the airflow exiting the air filter element 200 at the outflow surface occurs. By mutually coordinating the position of the outlet opening 140 and the geometry of the air filter element 200, i.e., the course and size of the free volume 500, the airflow through the air filter and within the air filter housing can be optimized, and the pressure loss of the air flowing through the air filter can be reduced.

[0149] The free volume 500 thus allows the airflow to initially exit the air filter element 200 at the outflow surface and then flow towards the outlet opening 140, whereby the free volume 500 can be adapted to the position and size of the outlet opening 140. The air filter element 200 with pleats of variable pleat depth can counteract a loss of filter area, since the free volume 500 is only adapted to the size of the outlet opening 140 and there is no reduction in the pleat depth of all filter pleats.

[0150] Fig. Figure 17 shows a cutaway view of the air filter. Fig. 16. As can be clearly seen, the outlet opening 140 has a circular shape, and the envelope 265 is designed such that the free volume 500 is adapted to the shape and geometry of the outlet opening 140. This ensures that the air flowing through the air filter element 200 has left the filter pleats at the outflow surface before the airflow is deflected towards the outlet opening 140. In particular, improved deflection of the airflow at the outflow surface of the air filter element 200 can result from the fact that the support structure also runs along the envelope 265. Thus, the free volume 500 forms a space or...Cavity within the housing body 110, in which a deflection of the airflow, which airflow when leaving the air filter element 200 runs perpendicular to the fold edges 225 on the outflow surface 285, such that the airflow runs parallel to the course of the fold edges 225 on the outflow surface 285, since the outlet opening 140 requires a course of the airflow parallel to the fold edges.

[0151] Fig. Figure 18 shows an isometric view of an air filter element 200 with a semicircular free volume 500. The air filter element 200 is made of Fig. 18 corresponds to the structure of the air filter element 200 in the Fig. 15, Fig. 16 to Fig. 17.

[0152] The support structure 290 has a first holding surface 291 and a second holding surface 292, with a recess 294 located between the holding surfaces 291, 292, which recess 294 corresponds to the course of the envelope 265 or correlates with the course of the envelope 265.

[0153] Fig. Figure 19 shows an air filter according to the invention with a housing body 110, wherein a flow straightener 510 projects through a wall of the housing body into the interior of the air filter or the housing body.

[0154] The flow straightener 510 can, for example, be a so-called inlet tulip which protrudes into the housing so that the outgoing air calms down before passing an air mass meter 515, i.e. that a uniform airflow is achieved without the air mass meter having to be a large distance from the housing wall.

[0155] For reliable measurement results from the air mass meter 515, it is essential that the air flowing past the air mass meter is free of turbulence and irregular airflow patterns. Therefore, installing an air mass meter requires that the air flowing past it is uniform. This can be achieved, for example, by using a flow straightener in the form of a tube, whereby the air flowing through this tube flows essentially in one direction, so that the air flows through this tube free of turbulence. Additionally, a grid 511 arranged inside the tube (in Fig. (19 only hinted at) reduce turbulence.

[0156] If the filtered air leaves the air filter element 200 on the outflow surface, then this air must be in the filter in the Fig. The airflow must first be deflected because the outlet opening 140 is perpendicular to the direction of airflow. This deflection of the airflow creates turbulence, so the air mass meter 515 cannot be attached directly or immediately to the outlet opening or the clean air connection 140 where the air flows into the outlet opening.

[0157] Because the flow straightener or the inlet tulip 510 protrudes into the housing or housing body 110, the air mass meter can be mounted near the housing wall of the housing body 110 and still allow for a flow-free flow in the area of ​​the air mass meter.

[0158] The free volume 500 of the air filter element 200 can be adapted to the geometric shape of the flow straightener 510. This ensures that the envelope 265 of the fold edges on the outflow surface of the air filter element 200 is adapted to a cross-section of the flow straightener 510.

[0159] In other words, this means that the inlet nozzle can, for example, be located centrally in a wall of the housing and enclosed by the air filter element in a ring or semicircle. This allows for a maximum size of filter area for the air filter element, preventing any significant loss of filter area due to the inlet nozzle protruding into the housing. The pleat depth of all filter pleats is not adjusted to the mounting position of the flow straightener; rather, only those filter pleats that cover a cross-sectional area of ​​the flow straightener have a reduced pleat depth.

[0160] The air mass meter 515, for example, could be a hot-film air mass meter. In this type of meter, the air mass flow is measured by detecting changes in the electrical resistance of a metal film over which the air flows, cooling the film. This change in the film's electrical resistance allows for a measurement of the air mass flow.

[0161] Fig. Figure 20 shows a side view of a housing body 110 with housing cover 120, wherein an air filter element 200 is located in the housing body in a non-inventive embodiment.

[0162] The housing body 110 has two housing ribs 520 or housing support ribs 520, each with a retaining surface 521. The housing ribs 520 extend longitudinally between the inlet surface and the outlet surface of the air filter element 200. The housing ribs 520 project into the housing body 110 in the direction of the fold edges of the filter pleats, i.e., perpendicular to the inlet surface and the outlet surface, or in the direction of the support element 290 of the air filter element 200.

[0163] The housing support ribs 520 serve to stiffen and provide dimensional stability to the housing body 110. The housing ribs 520 can exhibit a variable penetration depth into the housing body and can even run continuously through the housing body in one direction of the fold edges.

[0164] The housing ribs 520 have a retaining surface 521, which is designed to receive a recess 294 of the support element 290 of the air filter element 200 and thus to position and fix the air filter element 200 within the housing body 110. The recess 294 resting on the retaining surface 521 ensures that the filter pleats do not touch the housing support ribs, but rather that the housing support ribs 520 are only contacted by the support structure 290.

[0165] Fig. Figure 21 shows a section view along the section line BB. Fig. 20. The housing ribs 520 project laterally into the housing body 110 and the air filter element 200. As already shown above, the penetration depth of the housing ribs 520 can be variable and, for example, can extend continuously from one housing wall to another.

[0166] Fig. Figure 22 shows a side view of a housing body 110 with a housing cover 120. The housing body 110 has two housing support ribs 520, wherein a first housing support rib 520 has a first retaining surface 521 and a second housing support rib 520 has a second retaining surface 521.

[0167] The housing support ribs 520 can have different heights, i.e., longitudinal extensions between the inlet surface and outlet surface of the air filter element used, and overall different geometric dimensions, such as width.

[0168] Fig. Figure 23 shows an isometric view of an air filter element 200 matching the housing body 110. Fig. 22.

[0169] The air filter element 200 has two free volumes 500, wherein a first free volume 500 or a first indentation 294 is formed by a first holding surface 291 and a second holding surface 292, and a second free volume 500 or a second indentation 294 is formed by the second holding surface 292 and a further holding surface 291.

[0170] Fig. Figure 24 shows an isometric representation of an air filter not according to the invention with a housing body 110, wherein the housing body 110 has a single housing support rib 520.

[0171] For the execution of the in Fig. The explanations for the air filters shown in section 24 apply accordingly. Fig. 20, Fig. 21, Fig. 22 to Fig. 23, with the difference that Fig. 24 shows only a single housing support rib 520.

[0172] Of course, a housing body 110 as described above and below can also have a plurality of housing support ribs 520, in particular more housing support ribs than shown here in the figures, for example three or more housing support ribs.

[0173] Fig. Figure 25 shows a sectional view of an isometric representation of the air filter. Fig. 24.

[0174] From the presentation in Fig. Figure 25 shows how the housing support ribs 520 engage with the air filter element 200 and fix the air filter element 200 in the housing body 110 via the support structure 290. The housing support ribs 520 engage the free volume 500 of the support structure 290 and the air filter element 200 from two sides.

[0175] Fig. Figure 26 shows an isometric representation of an air filter element 200 in analogy to the representation in Fig. 25.

[0176] The air filter element 200 has two support elements 290, which are arranged perpendicular to a course of the fold edges 225 on the inflow surface 275 and the outflow surface 285.

[0177] The enveloping element 265 forms a recess 294 or a corresponding free volume 500 for the housing support ribs 520 on the support elements 290 or the air filter element 200, wherein the recess 294 is formed by the first retaining surface 291 and the second retaining surface 292.

[0178] Fig. Figure 27 shows an air filter 100 not according to the invention, comprising a housing body 110 and a housing cover 120, which are connected to each other by means of locking elements 115. Inside the housing body 110, in front of the outlet opening 140, there is a resonator 520 or a cavity resonator geometry 530, which is designed to reduce flow noise of the air flowing through the housing.

[0179] Fig. 28 shows a cross-sectional view of an air filter along the section line AA. Fig. 27.

[0180] The resonator 530 is located inside the housing body 110 in the free volume 500 along the envelope 265 at the outflow surface of the air filter element 200.

[0181] An air filter element with filter pleats of variable pleat depth allows for the integration of a resonator within the housing body while simultaneously maximizing the filter area of ​​the air filter element's filter medium. The resonator 530 is thus located directly at the outlet opening 140 or immediately before the connection of an external clean air duct. This eliminates the need for subsequent attachment of the resonator to the clean air duct or even to the raw air duct outside the housing, and at the same time, the available filter area of ​​the air filter element 200 is only minimally reduced, as the free volume 500 is adapted to the dimensions of the resonator 530.

[0182] Fig. Figure 29 shows a sectional view of an isometric representation of an air filter not according to the invention, comprising a housing body 110 and a housing cover 120, wherein a resonator 530 and an air filter element 200 are located within the housing body 110. The air filter element 200 has a free volume 500, the free volume 500 being adapted to the spatial dimensions of the resonator geometry 530. Furthermore, in an area of ​​the housing body not occupied by the resonator geometry 530, the filter pleats of the air filter element 200 have an unreduced pleat depth, so that the filter area of ​​the filter medium is only minimally reduced by the placement of the resonator 530 within the housing body 110.

[0183] Fig. Figure 30 shows an isometric representation of an air filter element 200 from the Fig. 27, Fig. 28 to Fig. 29. As can be clearly seen, the outflow surface 285 and the support elements 290 of the air filter element have a free volume 500 according to the course of the envelope 265, the free volume 500 being designed to accommodate a resonator.

[0184] Furthermore, a first holding surface 291 and a second holding surface 292 are arranged on each of the support elements 290, wherein a recess of the support element 290 is arranged or formed between the holding surfaces 291, 292 corresponding to the free volume 500.

[0185] Fig. Figure 31 shows an air filter 100 according to the invention, wherein an air filter element 200 and a flow guide device 540 or guide ribs 540 are located in the housing body 110.

[0186] The flow guide device 540 has a plurality of guide ribs, each guide rib having a guide surface 541 and a guide surface edge 542.

[0187] The individual guide ribs of the flow guide device 540 are arranged such that they cover a projection area of ​​the outflow surface 285 of the air filter element in order to prevent or reduce turbulence or irregularities in the airflow behind the outflow surface. Thus, the installation of a flow guide device 540 allows for a reduction in the distance of an air mass meter 515 from the housing body 110 in the outlet opening 140.

[0188] The guide surface edges 542 of the individual guide ribs together form an envelope that corresponds to, or aligns with, the envelope 265 of the outflow surface 285 of the air filter element 200. This enables an optimal distribution of the volume within the housing body between the air filter element 200 and the flow guide device 540, since the pleat depth of the filter pleats is adapted to the contour of the guide surface edges 542 of the individual guide ribs of the flow guide device 540.

[0189] In contrast to variable filter pleat depths, for example, in an air filter element with a constant filter pleat depth, the depth of the filter pleats would have to be based on the one with the shallowest filter pleat depth. This would lead to a significant reduction in filter area.

[0190] Fig. Figure 32 shows a sectional view of an isometric representation of an air filter according to the invention, in whose housing body 110 an air filter element 200 and a flow guide device 540 are located. The adaptation of the outflow surface of the air filter element 200 to the course of the guide surfaces and the guide surface edges of the individual guide ribs of the flow guide device is clearly visible.

[0191] Fig. Figure 33 shows a sectional view of an isometric representation of an air filter element 200 according to the invention with a flow guide device 540.

[0192] The individual guide ribs of the flow guide device 540 are attached to the support element 290.

[0193] The deflection function for the airflow of the flow guide device 540 is in the Fig. 33 is particularly evident. The airflow leaves the outflow surface of the air filter element 200 essentially in the direction of the course of a filter pleat 220 and is directed by the guide ribs of the flow guide device 540 in a direction orthogonal to the course of the filter pleat 220.

[0194] The deflection of the airflow through the guide ribs can of course be at any angle and adapted to the position of the outlet opening 140 on the housing of the air filter.

[0195] It should be noted that the guide ribs of the flow guide device 540 can be arranged on the support elements 290 of an air filter element 200, but the guide ribs of the flow guide device 540 can also be arranged on the housing body 110 of an air filter.

[0196] If the flow guide device 540 is attached to the housing of an air filter, the air filter element can be replaced without also replacing the flow guide device 540. Replacing the flow guide device with an air filter element may not necessarily be required, for example, because the flow guide device is not exposed to contamination to the same extent as the air filter element, whose primary function is to filter dirt particles from the raw air and is therefore naturally subject to greater contamination and wear.

[0197] Fig. Figure 34 shows a side view of an air filter 100 in an unclaimed embodiment, wherein an air filter element 200 and three adsorption filter elements for hydrocarbons 550, in particular for volatile hydrocarbons, which e.g. have activated carbon material, are arranged in the housing body 110.

[0198] The hydrocarbon adsorption filter elements 550 can, for example, be part of a hydrocarbon adsorption device. The hydrocarbon adsorption filter elements 550 are arranged between the outflow surface of the air filter element 200 and the clean air inlet 140. Free volumes within the air filter element allow the hydrocarbon adsorption filter elements to be arranged together with the air filter element 200 in the housing 110, with only a negligible reduction in the filter area of ​​the filter medium of the air filter element 200.

[0199] The adsorption filter elements for hydrocarbons 550 can in particular be firmly connected to the housing body 110, i.e. that they can withstand, for example, mechanical stress.

[0200] Fig. Figure 35 shows a sectional view of an isometric representation of an air filter not according to the invention, wherein the housing body 110 comprises an air filter element 200 and three adsorption filter elements for hydrocarbons 550. The adsorption filter elements for hydrocarbons 550 project into the outflow surface 285 of the air filter element 200 and into the support element 290.

[0201] Fig. Figure 36 shows an air filter 100 with a housing body 110 and a housing cover 120. The housing body 110 has a first inlet opening 130 and a second inlet opening 131. The housing cover 120 has an outlet opening 140. The air filter element 200 has a divided inlet surface 275, wherein the inlet surface 275 is separated by a housing partition 561 of the housing body and forms a first raw air chamber 562 and a second raw air chamber 563. The housing partition 561 has a sealing surface 567, so that the first raw air chamber 562 is sealed off from the second raw air chamber 563.

[0202] Furthermore, the housing body 110 features a housing airflow flap 560, which is designed to close the second raw air connection or the second inlet opening 131 in the first operating state. For example, the housing airflow flap 560 can be held closed by means of a tension spring. Of course, other closing mechanisms are also possible, which open the housing airflow flap at a predetermined negative pressure in the housing, allowing air to flow in.

[0203] In the first operating state of the air filter 100, air flows into the air filter through the first inlet opening 130, is filtered via the first raw air chamber 562, and exits the air filter through the outlet opening 140. In the event of heavy soiling of the first raw air chamber or blockages, for example by snow drawn in through the first inlet opening 130, a negative pressure increases in the air filter housing because air continues to be drawn out of the air filter through the outlet opening 140. This can, for example, create a negative pressure within the housing, which causes the housing airflow flap 560 to open the second inlet opening 131, thus drawing air into the housing through the second inlet opening 131 and the second raw air chamber 563, and the air filter is operated in a second operating state.

[0204] Fig. Figure 36 shows that the variable pleat depth can also affect the inflow area 275 of the air filter element 200. In contrast to the previously shown embodiments, in which the outflow area 285 had a free volume, in Fig. 36 the inflow area 275 a free volume.

[0205] In this context, it should be noted in particular that both the inlet surface 275 and the outlet surface 285 can provide an arbitrarily shaped free volume 500 for elements within the housing body 110 of the air filter 100, as is also shown in the Fig. 5F and Fig. 5G was shown.

[0206] Fig. Figure 37 shows a sectional view of an isometric representation of an air filter with a first raw air chamber 562 and a second raw air chamber 563, each supplied with air or raw air via a first inlet opening 130 and a second inlet opening 131, respectively. The second inlet opening 131 has a housing airflow flap 560, which is designed to allow air to flow through the inlet opening 131 only in the event of a blockage of the first raw air chamber 562. The first raw air chamber 562 is separated from the second raw air chamber 563 by the housing partition 561.

[0207] Fig. Figure 38 shows an isometric representation of an air filter element 200 of the embodiments in the Fig. 36 and Fig. 37. The inlet surface 275 has two stepped sub-surfaces, which are separated by the free volume 500 in the air filter element 200 and the support element 290. Thus, the air filter element 200 has in Fig. 38 filter pleats with three different filter pleat depths: The filter pleats in the first part of the inflow area 275, the filter pleats in the area of ​​the free volume 500 and the filter pleats in the second area of ​​the inflow area 275.

[0208] Just as the downstream end or edge of the support element 290 can also have a first holding surface 291 and a second holding surface 292, so too can the upstream end or edge of the support element 290.

[0209] The retaining surfaces 291, 292 are located on the upstream and downstream sides of the air filter element, respectively, depending on the insertion direction of the air filter element into the housing. If the air filter element is inserted into the housing with the upstream surface facing forward, the retaining surfaces 291, 292 are located, in a preferred embodiment, on the upstream edge of the support element. Conversely, if the air filter element is inserted into the housing with the downstream surface of the air filter element facing forward, the retaining surfaces 291, 292 are located, in a preferred embodiment, on the downstream edge of the support element.

[0210] Fig. Figure 39 shows an air filter 100 analogous to the air filter 100 which is in Fig. 36 was shown.

[0211] Fig. Figure 36 shows the housing airflow flap 560 at the second inlet opening 131 in the open state, wherein Fig. Figure 39 shows the housing airflow flap 560 of the second inlet opening 131 in the closed state. This is shown in the illustration in Fig. 39 only draws air into the housing of the air filter 100 via the first inlet opening 130. In contrast, in Fig. 36 Air is drawn in through both the first inlet opening 130 and the second inlet opening 131, provided that the first raw air chamber 562 of the first inlet opening 130 is not completely blocked. In the event that the first raw air chamber 562 is in Fig. If 36 is completely blocked, air is only drawn in via the second inlet opening 131 and the second raw air chamber 563.

[0212] This shows Fig. 36 the air filter in the second operating state (i.e. air is drawn in through the second inlet opening) and Fig. 39 the air filter in the first operating state (i.e. air is drawn in through the first inlet opening).

[0213] Furthermore, unlike Fig. 36 The envelope 265 of the airflow surface 275 of the air filter element does not have a stepped, but rather a rounded transition of adjacent fold edges. The rounded shape of the envelope 265 can, for example, be adapted to the opening movement of the housing airflow flap 560 and thus contribute to a further increase in the available filter area of ​​the air filter element.

[0214] Fig. Figure 40 shows a sectional view of an isometric representation of the in Fig. 39 air filters shown.

[0215] The housing partition 561 has a holding surface 568, which holding surface is designed to receive and position or fix the air filter element 200 in the area of ​​a first holding surface or a second holding surface 291, 292 of the support element 290. Furthermore, the Fig. 40 shows that the free volume 500 is located in the area of ​​the airflow surface of the air filter element 200 behind the second inlet opening 131, to allow the opening of the housing airflow flap 560.

[0216] Fig. Figure 41 shows an isometric representation of an air filter element 200 for an air filter as in the Fig. 39 and Fig. Figure 40 shows that the envelope 265 of the inflow surface 275 and the support element 290 has a rounded profile in the area of ​​the second raw air chamber 563.

[0217] An air filter element 200 with a free volume 500 for the housing partition 561 allows the first raw air chamber 562 and the second raw air chamber 563 to be separated by a housing partition 561 with variable height (i.e., in one direction from the outflow surface to the inflow surface), whereby the filter pleat depth can be adjusted to the height of the housing partition. This allows the size of the first raw air chamber 562 and the size of the second raw air chamber 563 to be adapted to each other and their size ratio to be optimized for the respective requirements.

[0218] The support element 290 has a first holding surface 291 and a second holding surface 292 in the area of ​​the second raw air chamber 563, wherein the support element 290 has a rounded transition or a rounded profile between the first holding surface 291 and the second holding surface 292.

[0219] In the area of ​​the first raw air chamber 562, the support element has only one first holding surface 291.

[0220] Fig. Figure 42 shows an isometric view of an air filter 100 with a housing cover 120, an air filter element 200, and a housing body 110. The housing cover 120 has an inlet opening 130, whereby the airflow through the housing cover is deflected from the inlet opening onto the frontal area 275. The direction of the airflow through the inlet opening 130 is parallel to the frontal area 275 and must be deflected accordingly by the housing cover. The housing body 110 has a housing rib 520 and an outlet opening 140 on an outlet nozzle 141.

[0221] The housing rib 520 can serve to stabilize the housing body, but the housing rib 520 can also be determined by external specifications of the installation space for the air filter 100.

[0222] The air filter element 200 has a support element 290 and a circumferential seal 205. Furthermore, the air filter element 200 has a flat inlet surface 275 and an outlet surface 285, wherein the envelope 265 of the fold edges on the outlet surface 285 forms a free volume, the free volume being adapted to the housing ribs 520 and its course or the envelope of the outlet surface having, for example, a parabolic shape.

[0223] In the same way as the housing cover is designed to redirect the direction of the airflow on the upstream side, i.e. from the upstream opening 130 to the upstream surface 275, the outflow nozzle 141 is also designed to redirect the direction of the airflow on the downstream side, i.e. from the downstream surface 285 to the outflow opening 140.

[0224] It should be noted that any deflection of the airflow can occur on both the outflow and the inflow sides.

[0225] Fig. Figure 43 shows a functional component 300, which is designed with the air filter 100 made of Fig. 42 and the corresponding main element 200 from Fig. 42 to be used.

[0226] The inlet surface 311 of the functional component 300 or additional filter element 310 is designed with the free volume 500 and the enclosing 265 of the air filter element 200 in Fig. 43 to correspond. The functional component designed in this way increases the inflow area 311 and the outflow area 312 of the additional filter element 310, thereby increasing the filter performance.

[0227] Fig. Figure 44 shows a central sectional view of an air filter 100 not according to the invention, comprising a housing body 110, a housing cover 120, and an inserted filter element 200. A resonator 520, e.g., a broadband resonator or a cavity resonator geometry 530, designed to reduce flow noise of the air flowing through it, is housed in a space-saving manner. The resonator 530 is positioned perpendicular to the plane of the drawing. Fig. The air flows through the 44. It is partially located in the free volume 500 along the envelope 265 at the outflow surface of the air filter element 200. The resonator 530 is surrounded by an outer jacket 600 or resonator housing. A part 601 of the outer jacket 600 facing the filter element 200 is formed by a part of the housing wall. A part 602 of the outer jacket 600 is connected to the housing wall, e.g., by welding. A resonator insert 603 is arranged in the outer jacket 600.

[0228] An air filter element 200 with filter pleats of variable pleat depth allows a resonator 520 to be attached to the housing body 110 and simultaneously maximizes the filter area of ​​the filter medium of the air filter element 200. Fig. 44 Some filter folds are schematically indicated by dashed lines. The fold edges 225, which are not shown, therefore extend perpendicular to the plane of the drawing. Fig. 44 and thus parallel to the flow direction of the resonator 530.

[0229] The free volume 500 is adapted to the spatial dimensions of the resonator 520. In addition, i.e., in an area of ​​the housing body 110 which is not occupied by the resonator 520, the filter pleats of the air filter element 200 have an unreduced filter pleat depth, so that the filter area of ​​the filter medium is only minimally reduced by the attachment of the resonator 520 to the housing body 110.

[0230] Fig. Figure 45 shows an exploded view of the components of the [unclear text]. Fig. The air filter 100 shown in Figure 44. Part 602 of the outer casing 600, or housing of the resonator 520, has a resonator connection 605 at each of its opposite ends. Air flows into the resonator 520 at one connection and out again at the other. The airflow through the resonator 520 is separated from the airflow through the filter element 200. Next to the resonator 520, the housing body 110 is provided with an outlet opening 140. Opposite this, an inlet opening 130 is provided on the housing cover 120. Fig. 44).

[0231] Preferably, the filter element 200 has a support structure 290 with a recess 294 on each of the sides opposite the flow direction or extension direction of the resonator 520.

Claims

[1] Air filter element arrangement comprising an air filter element (200) and a functional component (300), wherein the air filter element (200) has an inlet surface (275), an outlet surface (285), and a filter medium (210), wherein the filter medium extends between the inlet surface and the outlet surface, wherein at least the outlet surface has a recess (500) in sections, wherein the functional component to be operatively associated with the air filter element projects at least partially into a free space resulting from the recess (500), wherein the functional component to be operatively associated with the air filter element is operatively associated with the recess of the outlet surface, wherein the filter medium (210) is a filter medium folded from pleats (220), wherein the pleats each have a first pleat (230) and a second pleat (240), each with a pleat edge (231, 241;232, 242) abut each other at a fold edge (225), wherein the first fold sheets (230) of adjacent folds lie parallel to each other, wherein the first and second fold sheets (230, 240) extend between the upstream surface (275) and the downstream surface (285), ; characterized by , that the offset (500) has an extension along an extension direction of the fold edges (225), that several folds (220) with variable fold depths (250) are made from a continuous media web, and that the functional component (300) is designed as a flow guide device (540) which at least partially projects into the free space resulting from the offset (500), wherein the flow guide device has at least one guide surface (541) whose guide surface edge (542) is directed towards the outflow surface (285) of the air filter element (200). [2] Air filter element arrangement according to claim 1, wherein the back offset (500) has a one-dimensional concave or convex shape. [3] Air filter element arrangement according to one of claims 1 and 2, wherein the pleat depth (250) varies in a direction transverse to the extension direction of the pleat edges (225). [4] Air filter element arrangement according to one of claims 1 to 3, wherein the air filter element (200) has a support structure (290), wherein preferably the support structure (290) has a back offset, in particular in the form of a recess (294), which corresponds at least section by section to a course of the back offset (500) of the outflow surface. [5] Air filter element arrangement according to one of the preceding claims, wherein the pleated leaves (230, 240) are embedded laterally in the support structure (290) at the pleated leaf edges (233, 243) that do not border on the pleated leaf edges of adjacent filter leaves. [6] Air filter element arrangement according to one of the preceding claims, wherein the pleats (220) over the offset (500) are made from a continuous media web. [7] Air filter element arrangement according to one of the preceding claims, wherein adjacent pleated leaves (230, 240) are mutually stabilized by at least one spacer device, which in particular runs parallel to the pleated leaf edges (233, 243) that do not border on the pleated leaf edges of adjacent filter leaves. [8] Air filter element arrangement according to one of claims 1 to 7, wherein the functional component (300) is designed as a flow straightener (510), wherein the flow straightener (510) is associated with an air mass sensor (516) to be brought into operative relationship with the air filter element. [9] Air filter comprising an air filter housing (110) and an air filter arrangement according to one of the preceding claims.

Images