Air filter comprising a filter element that can be inserted in the manner of a drawer

Abstract

The invention relates to an air filter comprising a flat filter element that can be arranged replaceably in a housing. The flat filter element is held in a frame which, in turn, can be pushed into the housing and pulled out of the housing. In the operationally ready state, the filter element is supported within its flat filter medium body between the frame and the housing. For this purpose, a sealing body is mounted on an aperture in the filter medium body. A support finger of the frame engages in the filter medium body and rests against the sealing body. Opposite the support finger, a support element of the housing rests against the sealing body.

Description

[0001] Air filter with drawer-style insertable filter element

[0002] This patent application claims priority over German patent application No. DE102025109596.5, which was filed with the German Patent and Trademark Office on March 13, 2025, the contents of which are hereby incorporated by reference.

[0003] Technical field

[0004] The invention relates to an air filter comprising a flat filter element with a filter medium body and with a circumferential seal surrounding the filter medium body on the outside, and a housing, wherein the filter medium body has a first side and a second side facing away from each other and extending transversely to a main flow direction, and wherein a sealing element is arranged on the filter medium body within the area enclosed by the seal.

[0005] State of the art

[0006] Such an air filter is known from EP 3 103 543 A1.

[0007] Air filters with flat filter elements are used, for example, in motor vehicles as intake air filters for combustion engines or as cabin air filters. Typically, the flat filter elements are sealed against a housing by a circumferential gasket, which also supports the flat filter element against the housing. Particularly with large flat filter elements, undesirable deformation or vibration of the flat filter element and / or the housing can occur during operation.

[0008] The previously mentioned EP 3 103543 A1 describes a filter element comprising a circumferential sealing element designed to separate a clean side from a raw side. The filter element forms a replaceable filter insert and has at least one recess extending between the clean side and the raw side, in which a plug-shaped damping element is received. A housing dome is integrally formed with the inner surface of each of two housing parts. A first housing dome is located on the inner surface of the raw-air-side housing part and projects into the recess formed in the filter element. An end face of the raw-air-side housing dome rests against the damping element within the recess.The second housing dome is located on the inside of the clean air-side housing section. In the installed position, the two conically shaped housing domes are aligned coaxially with their respective end faces facing each other. The damping element is clamped between the end faces of the housing domes. To replace the filter element, the two housing sections are separated.

[0009] From WO 2018 / 158387 A1, a filter element for filtering intake air in a vehicle is known, wherein the filter element has a frame and wherein the filter element has at least two filter media arranged side by side in the frame. The filter material of the first filter medium differs from the filter material of the second filter medium. The frame defines the edges of the first and second filter media and separates these two filter media from each other by a central web. The central web of the frame can have a U-shaped recess for receiving a housing projection of a housing pot. A housing cover can have a retaining element with which it presses against a sealing element of the filter element in the area of ​​the central web. The frame can have a circumferential seal made of elastic material that seals the two flow areas. To replace the filter element, the housing cover is detached from the housing pot.

[0010] A filter known from EP 1 144083 B1 has a filter element arranged in a housing so that intake air can flow through it. For stiffening, a cover of the housing has a support at its center point, consisting of a hollow fitting fixed in the housing body and a threaded fitting fixed in the cover. These fittings are connected to each other by a connecting screw after the cover has been placed on the housing body. The support passes through a recess provided in the filter element, which is sealed against the support by an additional gasket.

[0011] EP 3 297745 B1 describes a filter element with a filter medium body, wherein a support element is connected to the filter medium body for supporting the filter element in a receiving filter housing. This support element is located on the clean side of the filter medium body and is separated from the raw side by the material of the filter medium body. The support element on the filter medium body has a convexly curved outer surface for receiving it in a concavely curved end face of a counter-support element on the filter housing. A filter element known from DE 10 2017011 435 A1 has a deformable carrier membrane that separates a clean side from a raw side and carries a sensor element. In conjunction with a second sensor element on the housing side, this forms a pressure sensor that detects deformation of the elastic carrier membrane.

[0012] When replacing a flat filter element, if two housing parts are separated and the filter element is essentially removed or inserted along the main airflow direction, the air filter must be accessible over a sufficiently large area. This area typically encompasses at least the entire surface of the filter element and an additional handling area to allow access for maintenance personnel. For example, such accessibility is often not available in the engine compartment of motor vehicles, or there is a desire to utilize the available installation space as completely as possible.

[0013] One objective of the invention is to reduce the space required for replacing a flat filter element supported in the housing.

[0014] Disclosure of the invention

[0015] This problem is solved by an air filter according to claim 1, a flat filter element according to claim 19, a housing arrangement according to claim 21, and a frame according to claim 22. Advantageous embodiments are specified in the respective dependent claims and the description.

[0016] According to the invention, an air filter is provided. The air filter can, in particular, be an intake air filter for an internal combustion engine or a cabin air filter for a motor vehicle. The advantages of the invention are particularly evident in intake air filters for commercial vehicles such as trucks.

[0017] The air filter consists of a flat filter element with a filter medium body and a circumferential seal. The seal surrounds the filter medium body on the outside. The flat filter element will also be referred to simply as the filter element below.

[0018] Furthermore, the air filter has a housing. For operation, the filter element is arranged within the housing. The housing can have an upper and a lower part. A raw air inlet can be formed on one of the housing parts, particularly the lower part. A clean air outlet can be formed on another of the housing parts, particularly the upper part. Typically, the upper part of the housing is arranged above the lower part in the intended installation position; however, other installation situations and housing divisions are also conceivable.

[0019] When the filter element is in its operating position within the housing, the seal can seal the filter medium body against the housing. The seal can be made of polyurethane, particularly polyurethane foam.

[0020] The filter medium body has a first and second side that face away from each other and extend perpendicular to a main flow direction. Flow can pass through the filter medium body from one side to the other. Typically, flow passes through the filter medium body from the first to the second side; the first side can then be referred to as the upstream side and the second side as the downstream side. However, it is also conceivable that flow passes through the filter medium body from the second to the first side; the second side can then be referred to as the upstream side and the first side as the downstream side. The sides can be flat, stepped, or corrugated. Flat sides can be parallel to each other or inclined towards each other.

[0021] The filter medium body can comprise pleated filter medium. In particular, the filter medium body can be formed with one or more bellows.

[0022] A sealing element is arranged on the filter medium body within the area enclosed by the gasket. Typically, the sealing element is spaced apart from the surrounding gasket. The sealing element is inherently airtight. Typically, the sealing element is connected to the filter medium body in a sealing manner.

[0023] The sealing element can be made of, and in particular consist of, soft or hard plastic. Preferably, the sealing element is made of the same material as the surrounding seal. In particular, the sealing element and / or the seal can be made of polyurethane, especially polyurethane foam.

[0024] According to the invention, the air filter has a frame that can be inserted into the housing to receive the filter element. The frame is preferably completely closed. The first and second sides of the flat filter element are generally not tightly sealed by the frame. The frame can have ribs on the first side, in particular in the form of a support grid, to support the filter medium body. Alternatively or additionally, the seal of the flat filter element can be brought into contact with an edge of the frame to support the filter element against the frame.

[0025] To replace the filter element, the frame is removed from the housing, in particular by pulling it out like a drawer. This is preferably done essentially in the plane of a main dimension of the flat filter element. This reduces the area that needs to be accessible for replacing the filter element. In particular, a relatively flat area (which usually only needs to be slightly higher than the thickness of the filter medium body) is sufficient for removing or inserting the flat filter element.

[0026] A new filter element can then be attached to the frame. The frame with the filter element is then reinserted into the housing, specifically slid in, for continued operation of the air filter.

[0027] Preferably, the frame is completely removable from the housing. This simplifies the removal and attachment of the flat filter element to the frame.

[0028] According to the invention, the frame further comprises a support finger that engages the filter medium body from the first side and is supported by the sealing element when the frame with the flat filter element is in a service position within the housing. Thus, the flat filter element is stabilized relative to the frame during operation. Advantageously, the flat filter element is supported by the support element even before the service position is established, particularly when the filter element is arranged on the frame outside the housing. This minimizes movements transverse to the plane of the main extent of the filter element when it is moved into the service position.

[0029] The housing, particularly the upper housing section, has a support element that rests against the sealing body when the frame with the flat filter element is in the housing in its operating position. The flat filter element is thus additionally supported against the housing. The support element on the housing side and the support finger on the frame side are always located on opposite sides of the sealing body. The flat filter element is therefore supported on both sides of the housing. Furthermore, the frame and the housing can be stabilized against each other by contact with the sealing body.

[0030] The frame with the flat filter element can be moved from its operating position away from the housing's support element into an insertion position. In the insertion position, the frame with the flat filter element can be removed from the housing. Similarly, the frame with the flat filter element can be inserted into the housing in the insertion position and then moved into the operating position. This can reduce the force required for mounting and dismounting the flat filter element. In particular, the circumferential seal can be released from its sealing position on the housing when the frame with the filter element is moved into the insertion position. At the same time, the housing-side support element can be released from contact with the sealing element. Conversely, when moving the frame with the filter element into the operating position, the seal can be brought into a sealing position on the housing and / or the support element can be brought into contact with the sealing element.

[0031] To move the frame with the flat filter element between the operating position and the insertion position, the frame can be pivoted relative to the housing. This can be advantageous for handling. Furthermore, this can facilitate fixing the frame with the ring filter element to the housing in the operating position.

[0032] A pivot axis for pivoting the frame relative to the housing can be established by a first support segment of the frame against a second support segment of the housing. The frame is then supported against the housing by the contact of the support segments, particularly at one end of the frame or housing. Further fixing for the operating position is only required at the other end of the frame, especially in the area of ​​a housing opening. Simultaneously, the contact of the support segments can be released when the frame is removed or established when the frame is inserted, particularly without requiring any additional movements beyond pulling it out or pushing it in. Advantageously, the support segments are arranged opposite each other on the housing at the leading end of the frame or housing opening in the insertion direction.The frame may include a closure segment for sealing a housing opening. This closure segment can cover the housing opening when the frame is in its operating position. The closure segment may be designed to form a tight seal against the housing. If the circumferential seal is located on the inside of the filter element, sealing the housing opening to the outside may be unnecessary, as ambient air flowing in from the outside must always pass through the filter element. In such cases, an overlap of the closure segment and an edge of the housing opening, either in contact or with a small gap, is sufficient.

[0033] The frame can have a collar which, in the operating position, overlaps an edge section of the housing opening. This ensures a sufficient seal of the housing opening. At the same time, the collar can advantageously be guided past the edge section when moving the frame into the insertion position, particularly without requiring significant force.

[0034] The frame may have a stop that can be brought into contact with the edge section when the frame is inserted. The underside of the frame can slide off this edge section when the frame is removed or inserted.

[0035] Preferably, the filter medium body has a fully enclosed opening extending from the first side to the second side, with the sealing element closing the opening. The opening is located within the area enclosed by the seal. Such an opening allows the sealing element to be positioned centrally on the flat filter element, thus providing particularly effective support for it.

[0036] The filter medium body can have a bellows in which the opening is formed. In particular, the opening can be circumferentially surrounded by the filter medium of a single bellows. The opening can be sealed by at least one bead of glue. This bead can, for example, tightly seal the fold edges of the bellows in an area surrounding the opening. In particular, the opening can be sealed by two beads of glue running transversely to the fold edges. Such a seal can be produced efficiently. The beads of glue sealing the opening can extend continuously over the entire length of the bellows. This further simplifies production, as the application of glue to the unfolded filter medium does not need to be interrupted.Alternatively, the glue beads sealing the opening can extend from the opening in opposite directions and only partially reach towards the opposing edges of the bellows. This has the advantage of requiring less material for the glue beads.

[0037] Glue beads can also be applied to the outer surfaces of the filter medium body to seal its folds. Glue beads for external sealing are also generally continuous.

[0038] The adhesive bead creates a sealing bond between adjacent surface areas of the folded filter medium; the term "adhesive bead" is used here initially regardless of its material. Essentially, the adhesive bead fixes the adjacent surface areas of the folded filter medium together. The adhesive bead can consist of an adhesive, particularly a hot melt adhesive, or glue.

[0039] The sealing element can be detachably attached to the filter medium body. This can simplify manufacturing. For example, the sealing element can be inserted into an opening in the filter medium body.

[0040] Preferably, however, the sealing element is permanently, in other words firmly, connected to the filter medium body. This prevents the sealing element from unintentionally detaching when the flat filter element is replaced. The sealing element can, for example, be molded onto the filter medium body, in particular cast or foamed on, or bonded to it.

[0041] The seal can be positioned on the second side of the filter medium body. This allows the sealing element and the seal to be manufactured and joined to the filter medium body in a single operation. In particular, a common casting mold can be used for both the seal and the sealing element.

[0042] The sealing body can form a cap with a circumferentially enclosed cavity open on the first side, particularly where the cavity extends beyond the second side. In other words, a section of the sealing body circumferentially encloses the cavity on the second side, with the cavity having an opening on the first side. Along the main flow direction, the cap and the cavity can extend beyond the second side. In particular, the sections of the cap facing the second side or extending beyond the second side are closed. For the purposes of describing the sealing body, directional terms such as radial, axial, or circumferential refer to an axis through the sealing body parallel to the main flow direction. The cavity can be concave overall when viewed from the first side. The cap can thus be described as a dome.Alternatively, the cavity can be convex in some areas when viewed from the first side.

[0043] When the frame with the flat filter element is in its operating position within the housing, the support finger can engage the cavity from the first side. In particular, the support finger can extend beyond the second side. This effectively prevents movement of the filter medium body in the plane of its main dimension.

[0044] The cap may have at least one radial outward bulge. This bulge extends the cavity radially outward. In the area of ​​the bulge, an outer surface of the cap may project outward.

[0045] The support finger can have a radially outwardly projecting rib that engages in the recess when the frame with the flat filter element is in the housing in its operating position. Advantageously, the rib already engages in the recess when the filter element is positioned outside the housing on the frame. This engagement of the rib in the recess ensures a defined rotational orientation of the flat filter element, even when the sealing element is located centrally on the flat filter element.

[0046] The support element may have a projection that partially surrounds the cap of the sealing body when the frame with the flat filter element is in the housing in its operating position. The projection surrounding the cap can support the filter medium body, particularly in the plane of its main extent.

[0047] In particular, the extension can extend around the cap over an angular range of at least 60° and / or at most 180°. This allows for particularly effective support without impeding the replacement of the filter element. Specifically, in the insertion position, the overlap of the extension and the sealing element transverse to the insertion direction need not be completely eliminated. The extension of the support element and the support finger can overlap each other along the main flow direction when the frame with the flat filter element is in the housing in its operating position. The sealing element is then clamped in the plane of the main extent of the filter medium body between the support finger and the support element. In this way, particularly effective support can be achieved.

[0048] The sealing element may have a flange at the open end of the cap. The flange may extend parallel to the first side.

[0049] The support finger can have a shoulder that rests against the flange when the frame with the flat filter element is in the housing in its operating position. This provides support for the filter medium body perpendicular to the plane of its main dimension. Advantageously, the shoulder already rests against the flange when the filter element is positioned outside the housing on the frame.

[0050] The support element can have an end face that rests against the sealing body when the frame with the flat filter element is in the housing in its operating position. This also provides support for the filter medium body perpendicular to the plane of its main dimension.

[0051] Advantageously, the sealing body is clamped between the support finger and the support element in the operating position transverse to the plane of its main extent, i.e. along the main flow direction.

[0052] The sealing element can have a central recess, at the bottom of which an end face of the support element rests when the frame with the flat filter element is in the housing in its operating position. A projecting bead can surround the recess. The bead can form a continuous ring around the recess or have at least one recessed section. In particular, the bead can have two recessed sections symmetrically to the central recess. By engaging the support element in the recess, the filter medium body can be positively supported in the plane of its main dimension. At the same time, the support element can be designed to be particularly simple and thus efficient to manufacture. Advantageously, only minimal movements between the operating position and an insertion position are required to release or adjust the overlap of the sealing element and the support element.This can simplify the design of the housing and frame, as well as facilitate the replacement of the filter element.

[0053] The sealing element can have a projection extending towards the first side (particularly within the cap). In this embodiment, the cavity enclosed by the cap is annular. A vertex of the cap furthest from the first side in the main flow direction, and in particular projecting beyond the second side, can surround the projection in an annular manner.

[0054] The support finger can have a central recess at its axial end facing the sealing body. Advantageously, the projection engages in the central recess when the frame with the filter element is in the housing in its operating position. The projection typically engages in the recess even when the filter element is positioned outside the housing on the frame. In this way, a positive-locking fixation of the filter element to the lower part of the housing can be achieved. Furthermore, the projection allows for a sufficiently large wall thickness of the sealing body if it has a central recess.

[0055] Typically, a free end of the projection is detached from the underside of the recess when the frame with the filter element is in its operating position within the housing. Alternatively, the projection may rest against the underside of the recess when the frame with the filter element is in its operating position within the housing. This allows the filter element to be supported on the lower part of the housing perpendicular to the plane of the main extent of the filter medium body. In the latter case, the projection may already be in contact with the underside when the filter element is positioned outside the housing on the frame.

[0056] The support finger can have a rim at its end facing the sealing body. The rim can form a closed ring around the recess. Alternatively, the rim can have at least one interruption, in particular two interruptions opposite each other with respect to the recess. Preferably, the rim rests against a vertex face of the sealing body when the frame with the filter element is in the housing in its operating position. In this way, support of the filter element can be achieved in the plane of its main dimension and transversely thereto. Advantageously, the rim already rests against the vertex face when the filter element is arranged on the frame outside the housing. If the sealing body has a projection engaging in the recess of the support finger, the vertex face can surround the projection, at least partially, with at least one ring segment.In particular, the vertex surface may exhibit projecting or recessed breaks between adjacent ring segments along the projection.

[0057] Preferably, the sealing element is arranged eccentrically on the filter medium body. This allows a defined rotational position of the flat filter element relative to an axis parallel to the main flow direction to be enforced, independent of the outer contour of the flat filter element.

[0058] Several sealing elements can be arranged on the filter medium body within the area enclosed by the seal. The frame can have a support finger for each sealing element, which engages the filter medium body from the first side and bears against the respective sealing element when the frame with the flat filter element is in its operating position within the housing. The housing can also have a support element for each sealing element, which bears against the sealing element when the frame with the flat filter element is in its operating position within the housing. This allows for a particularly high degree of stabilization.

[0059] The multiple sealing bodies, support fingers and / or support elements may each have further features described above. Preferably, the multiple sealing bodies, support fingers and / or support elements are each of the same design.

[0060] The sealing elements can be offset from one another transversely to the insertion direction of the flat filter element held in the frame. The insertion direction can run transversely to the folded edges of the filter medium body. The offset is then arranged along the folded edges. Sealing elements offset from one another in this way do not collide with support elements associated with a different sealing element when the filter element is replaced.

[0061] The present invention also encompasses a flat filter element, particularly for an air filter according to the invention as described above. The flat filter element comprises a filter medium body and a circumferential seal that surrounds the filter medium body on the outside. The filter medium body has a first side and a second side that face away from each other and extend transversely to a main flow direction. A sealing element is arranged on the filter medium body within the area enclosed by the seal.

[0062] Several sealing elements can be arranged on the filter medium body within the area enclosed by the seal. The sealing elements can be offset from one another transversely to a longitudinal direction of the filter medium body. This longitudinal direction corresponds to the insertion direction. The offset can be arranged along folded edges of the filter medium body. The insertion direction or longitudinal direction can run transversely to the folded edges. Each sealing element can close a fully enclosed opening that extends from the first side to the second side of the filter medium body.

[0063] The flat filter element may have other features described above.

[0064] The present invention further relates to a housing arrangement for an air filter according to the invention as described above. The housing arrangement comprises a housing and a frame that can be inserted into the housing to receive a flat filter element. The frame has a support finger for engaging a filter medium body of a flat filter element from a first side and for bearing against a sealing body of the flat filter element when the frame with the flat filter element is in a service position in the housing. The housing and the frame may have further features as described above.

[0065] The present invention further relates to a frame for an air filter according to the invention. The frame has a support finger for engaging a filter medium body of a flat filter element from a first side and for bearing against a sealing body of the flat filter element when the frame with the flat filter element is in a service position in a housing. The frame may have further features described above.

[0066] Brief description of the drawings

[0067] Further features and advantages of the invention will become apparent from the following detailed description of exemplary embodiments of the invention, from the claims, and from the figures in the drawing, which illustrate details of the invention. The aforementioned and further described features can be implemented individually or in any suitable combination in variants of the invention. The features shown in the drawing are presented in such a way that the special features of the invention are clearly visible.

[0068] The drawing shows:

[0069] Fig. 1 shows an air filter according to the invention, in a schematic perspective view; Fig. 2 shows a schematic exploded view of the air filter of Figure 1;

[0070] Fig. 3 is a further schematic exploded view of the air filter of Figure 1; Fig. 4 shows the air filter of Figure 1 in a partial, schematic sectional view, wherein a flat filter element according to the invention, held in a frame according to the invention, is located in a service position in a housing; Fig. 5 shows a partial, schematic sectional view of the air filter of Figure 1 in the area of ​​a sealing body of the flat filter element, which is held between a housing-side support element and a frame-side support finger; Fig. 6 shows the air filter of Figure 1 in a partial, schematic sectional view, with the filter element tilted into an insertion position;

[0071] Fig. 7 shows the air filter of Figure 1 in a partial, schematic sectional view, with the frame containing the filter element in the insertion position and partially pulled out of the housing;

[0072] Fig. 8 is a schematic perspective view of the air filter of Figure 1 in the configuration of Figure 7;

[0073] Fig. 9 shows a partial, schematic sectional view of an air filter according to the invention with a flat filter element according to the invention, in the area of ​​a sealing body of the flat filter element, which is held between a housing-side support element and a frame-side support finger;

[0074] Fig. 10 shows the air filter of Figure 10, in a partial, schematic sectional view, with the filter element tilted into an insertion position.

[0075] Embodiments of the invention

[0076] Figures 1, 2, and 3 show an air filter 10. The air filter 10 has a housing 12 with a lower housing part 14 and an upper housing part 16. The lower housing part 14 and the upper housing part 16 are attached to each other. A raw air inlet 15 for air to be filtered is formed on the lower housing part 14. A clean air outlet 17 for filtered air is formed on the upper housing part 16. The air filter 10 also has a flat filter element 20, which is interchangeably arranged in the housing 12 (see Figures 2, 3, and 4). A filter medium body 22 of the flat filter element 20 is designed as a bellows made of zigzag-folded filter medium, for example, filter paper. The filter medium body 22 is open to airflow from a first side 24 to a second side 26 along a main flow direction 28. In other words, the first side 24 forms a raw-side inflow side; the second side 26 forms a clean-side outflow side.In the illustrated embodiment, the first and second sides 24, 26 each run in a plane and parallel to each other.

[0077] A circumferential seal 30 is attached to the outside of the filter medium body 22. The seal 30 can be made of polyurethane and, for example, foamed onto the filter medium body 22. In this case, the seal 30 is arranged adjacent to the second side 26. During operation, as shown in Figure 4, which depicts a service position of the filter element 20, the circumferential seal 30 seals the flat filter element 20 against the housing 12, separating a raw side (associated here with the lower housing part 14) from a clean side (associated here with the upper housing part 16). A sealing surface 29 for the seal 30 is formed on the upper housing part 16.

[0078] Inside the filter medium body 22, at least one opening 32 is formed, extending from the first side 24 to the second side 26, see Figure 5. The opening 32 is cylindrical in shape. The opening 32 is surrounded circumferentially by the filter medium body 22. Folds of the filter medium body 22 are sealed towards the opening 32 by adhesive beads 33 extending transversely to its fold edges 31 (see Figure 4), see Figures 3 and 5. The adhesive beads 33 extend over the entire length of the filter medium body 22, see Figure 3.

[0079] A sealing element 34 closes the opening 32, see Figures 3 and 5. The sealing element 34 can be made of polyurethane and, for example, foamed onto the filter medium body 22. In this way, a permanent connection between the sealing element 34 and the filter medium body 22 can be obtained. The sealing element 34 is a single piece.

[0080] In the illustrated embodiment, two openings 32 and two sealing elements 34 are provided, see Figure 3. The sealing elements 34 are offset from each other along the folded edges 31. Both sealing elements 34 are arranged eccentrically on the rectangular filter element 20. Each sealing element 34 rests on the second side 26 of the filter medium body 22 with a collar 36, see Figure 5. A shaft section 38 of the sealing element 34 extends into the opening 32.

[0081] The sealing element 34 forms a cap 40, which projects beyond the second side 26 of the filter medium body 22, see Figures 3 and 5. The cap 40 encloses a cavity 42, which is open towards the first side 24, see Figure 5. The cap 40 extends so far beyond the second side 26 that the cavity 42 – when viewed along the main flow direction 28 – is also partially located above the second side 26.

[0082] The filter element 20 is not held directly in the housing, but is received in a frame 44, see in particular Figures 2 and 3. The frame 44 can completely enclose the filter element 20. In the assembled state, the seal 30 of the filter element 20 is enclosed by an upper edge 46 of the frame 44 and rests on a support surface 47 located within the edge 46, see Figure 4. On its underside, the frame 44 has webs 48 for supporting the filter medium body 22, see Figure 4.

[0083] For the operation of the air filter 20, the frame 44 closes a housing opening 52 of the filter housing 12 with a closure segment 50, see in particular Figures 1 and 4. A collar 54 of the closure segment 50 on the frame 44 overlaps an edge section 56 of the housing opening 52. In this case, the edge section 56 is formed on the lower housing part 14. The seal 30 of the filter element 20, which rests on the support surface 47 of the frame 40, seals the closure segment 50 against the upper housing part 16 by contacting the sealing surface 29. This prevents ambient air from flowing into the clean side (above the second side 26 of the filter medium body 22). If some ambient air should enter the raw side (below the first side 24 of the filter medium body 22) between the collar 54 and the edge section 56 in addition to the raw air flowing in through the raw air inlet 15, this is typically not critical.If necessary, a seal can be provided between the collar 54 and the lower part of the housing 14.

[0084] To hold the frame 44 with the filter element 20 in the operating position with the housing opening 52 closed, locking elements 58, here snap hooks, secure the frame 44 to the housing 12, here to the upper housing part 16 (see Figures 1 and 4). To replace the filter element 20, the locking elements 58 are released and the frame 44, together with the filter element 20, is removed from the housing 12 through the housing opening 52. This will be described in more detail below. The housing parts 14 and 16 remain attached to each other, even if they are detachably connected.

[0085] The frame 44 has a support finger 60 for each sealing body 34, which engages in the cavity 42 of the sealing body 34 from the first side 24 (see Figure 5). The support finger 60 extends through the opening 32 in the filter medium body 22 parallel to the main flow direction 28, so that its axial end 62 is located beyond the second side 26 of the filter medium body 22. The support finger 60 has a recess 64 at its free axial end 62. The recess 64 is surrounded at its open end by a rim 66. The rim 66 can be essentially annular, in particular with interruptions between circumferentially extending sections of the rim 66 (not visible in the section view of Figure 5). A closed underside 68 of the recess 64 is recessed relative to the rim 66. In this case, the underside 68 is flat.

[0086] Within the cavity 42 of the cap 40, a projection 70 is formed on the sealing body 34. The free end of the projection 70 points towards the first side 24 of the filter medium body 22. In this embodiment, the cavity 42 within the cap 40 is annular. In the axial direction (parallel to the main flow direction 28), the cavity 42 is bounded by a vertex surface 72. Circumferentially spaced ring segments of the vertex surface 72 surround a base of the projection 70 beyond the second side 24 when viewed in the main flow direction 28, section by section.

[0087] The projection 70 extends with its free end into the recess 64 of the support finger 60. The free end of the projection 70 may be spaced away from the underside 68 of the recess 64. At the same time, the free edge 66 of the support finger 60 rests against the apex surface 72 of the cap 40.

[0088] The upper housing part 16 is supported on each of the two sealing bodies 34 by a support element 74. An end face 76 of the respective support element 74 rests against the outside of the associated sealing body 34.

[0089] In the illustrated embodiment, the sealing body 34 has a central recess 78 on its cap 40, which projects beyond the second side 26. The recess 78 is formed on the outer side of the cap 40 facing away from the cavity 42. The projection 70 and the recess 78 are arranged opposite each other on the sealing body 34 with respect to the main flow direction 28.

[0090] The support element 74 of the housing 12 extends into the recess 78. The end face 76 of the support element 74 rests against a base 80 of the recess 78.

[0091] The sealing element 34 is clamped between the support finger 60 and the support element 74 in the operating position of the filter element 20. Thus, the filter medium body 22 is supported relative to the housing 12 and the frame 44, which in turn is held on the housing 12, particularly in the direction and against the main flow direction 24 and in the plane perpendicular to this direction of the main extent of the filter medium body 22.

[0092] To replace the filter element 20, the locking elements 58 are first released. Then, the frame 44 with the filter element 20 is moved into an insertion position, as shown in Figure 6. For the purposes of this invention, the insertion position refers to the orientation of the frame 44 and the filter element 20 relative to the housing 12 in which the frame 44 with the filter element 20 can be inserted into and removed from the housing 12.

[0093] In this embodiment, the frame 44 is pivoted towards the lower housing part 14 in the area of ​​the housing opening 52. The collar 54 of the frame 44 is guided past the edge section 56 of the housing 12. The seal 30 is thereby moved away from the sealing surface 29. At the same time, the contact between the support elements 74 and the sealing elements 34 is broken.

[0094] In the illustrated embodiment, a pivot axis for the pivoting movement is provided by a first support segment 82 of the frame 44 against a second support segment 84 of the housing 12, here against the upper part of the housing 16, see Figure 2. When the frame 44 with the filter element 20 is in the operating position, the mutual contact of the support segments 82, 84 against each other also serves to fix the frame 44 in the housing 12 on the side facing away from the housing opening 52 and the locking elements 58.

[0095] When the frame 44 with the filter element 20 is in the insertion position, they can be pulled out of the housing 12 together, see Figures 7 and 8. For this purpose, the frame may have a handle 86 which can be attached to the locking segment 50. The removal is carried out in the opposite direction to an insertion direction 87.

[0096] The frame 44 with the filter element 20 can also be inserted into the housing 12 through the housing opening 52 in the insertion position. Upon reaching the full insertion depth, the two system segments 82 and 84 come into contact. The frame 44 with the filter element 20 is then pivoted upwards about the pivot axis defined by this movement to establish the operating position. The seal 30 comes into contact with the sealing surface 29. Likewise, the support elements 74 come into contact with the sealing bodies 34 and press them against the support fingers 60. Finally, the closing elements 58 are closed again. The frame 44 is then fixed at both ends (with respect to the insertion direction 87, which here is oriented transversely to the folded edges 31) to the housing 12. The filter element 20 is thus held in the housing 12 and additionally supported within its filter element 22.

[0097] Figure 9 shows an alternative design of the sealing bodies 34 as well as the support fingers 60 and support elements 74.

[0098] In this embodiment, the cap 40 of the sealing body 34 is provided with a bulge 88 which extends the cavity 42 radially outwards in certain areas. In the area of ​​the bulge 88, the cap 40 is convex on its outer surface. A vertex 90 of the cap 40 limits the cavity 42 in the axial direction (parallel to the main flow direction 28).

[0099] In the operating position, the support finger 60 rests with its axial end 62 on the inside of the apex 90 of the cap 40. A shoulder 92 of the support finger 60 rests against a flange 94 of the sealing body 34. Furthermore, the support finger 60 has a radially outwardly projecting rib 96 between the shoulder 92 and its axial end 62, which engages in the recess 88.

[0100] The filter element 20 is also supported on the support element 74 via the sealing body 34. Firstly, an end face 76 of the support element 74 rests against the outer surface of the apex 90 of the cap 40. The sealing body 34 is thus clamped in the area of ​​the apex 90 between the support finger 60 and the support element 74.

[0101] Secondly, the flange 94 of the sealing body 34 is clamped between a projection 98 of the support element 74 and the shoulder 92 of the support finger 60. The projection 98 extends beyond the end face 76 of the support element 74 towards the filter medium body 22. In the main flow direction 28, the projection 98 and the support finger 60 overlap each other.

[0102] The extension 98 encompasses the cap 40 over approximately half of its outer circumference; compare also Figure 10, which shows the insertion position, so that the full extent of the extensions 98 can be seen. Since the extensions 98 extend around the caps 40 over less than 180°, the filter element 20 can be removed or inserted in the insertion position, even if the extensions 98 overlap the caps 40 of the sealing bodies along the main flow direction 28.

[0103] It should be noted that the section plane of Figure 10 is rotated relative to the insertion direction in order to cut through the two sealing bodies 34, which are offset from each other along the folded edges 31. Therefore, despite the similar design to the right sealing body 34 and support finger 60 in Figure 10, the shape of the cavity 42 and the axial end 62 are not visible in detail.

[0104] In summary, the invention relates to an air filter with a flat filter element that can be arranged interchangeably in a housing. The flat filter element is held in a frame, which in turn can be inserted into and removed from the housing. In the ready-to-use state, the filter element is supported within its flat filter medium body between the frame and the housing. For this purpose, a sealing element is attached to an opening in the filter medium body. A support finger of the frame engages in the filter medium body and rests against the sealing element. Opposite the support finger, a support element of the housing rests against the sealing element. Advantageously, for replacing the filter element, the frame with the filter element can be moved within the housing into a service position and an insertion position. By moving it into the insertion position, the support element of the housing can be detached from the sealing element.

[0105] Air filter 10

[0106] Case 12

[0107] Lower housing part 14

[0108] Raw air inlet 15

[0109] Housing top 16

[0110] Clean air outlet 17

[0111] Flat filter element 20

[0112] Filter medium body 22

[0113] first page 24

[0114] second page 26

[0115] Main flow direction 28

[0116] Sealing surface 29

[0117] Seal 30

[0118] Fold edges 31

[0119] Breakthrough 32

[0120] Glueworms 33

[0121] Sealing body 34

[0122] Collar size 36

[0123] Shaft section 38

[0124] Cap 40

[0125] Cavity 42

[0126] Frame 44

[0127] Page 46

[0128] Support surface 47

[0129] Bridge 48

[0130] Locking segment 50

[0131] Housing opening 52

[0132] Collar size 54

[0133] Edge section 56

[0134] 58 locking elements

[0135] Support finger 60

[0136] axial end 62

[0137] Recess 64, annular edge 66, underside 68, projection 70, vertex 72, support element 74, end face 76, recess 78

[0138] Floor 80

[0139] first insertion segment 82 second insertion segment 84 handle 86 insertion direction 87 bulge 88 vertex 90

[0140] Shoulder 92

[0141] Flange 94

[0142] Rib 96

[0143] Continuation 98

Claims

Claims 1. Air filter (10), in particular intake air filter for an internal combustion engine or cabin air filter for a motor vehicle, comprising a flat filter element (20) with a filter medium body (22) and with a circumferential seal (30) that surrounds the filter medium body (22) on the outside, - a housing (12), as well as a frame (44) that can be inserted into the housing (12) to accommodate the flat filter element, wherein the filter medium body (22) has a first side (24) and a second side (26) which are facing away from each other and which extend transversely to a main flow direction (28), wherein a sealing element (34) is arranged on the filter medium body (22) within the area enclosed by the seal (30), wherein the frame (44) has a support finger (60) which engages in the filter medium body (22) from the first side (24) and is supported on the sealing body (34) when the frame (44) with the flat filter element (20) is in a service position in the housing (12), and wherein the housing (12) has a support element (74) which is supported on the sealing body (34) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

2. Air filter according to claim 1, wherein the frame (44) with the flat filter element (20) can be moved from a service position away from the support element (74) of the housing (12) into an insertion position, in particular wherein the frame (44) is pivotable relative to the housing (12), and wherein the frame (44) with the flat filter element (20) can be removed from the housing (12) in the insertion position.

3. Air filter according to claim 2, wherein a pivot axis for pivoting the frame (44) relative to the housing (12) is provided by a first contact segment (82) of the frame (44) against a second contact segment (84) of the housing (12).

4. Air filter according to any one of the preceding claims, wherein the frame (44) has a closing segment (50) for closing a housing opening (52) of the housing (12).

5. Air filter according to claim 4, wherein the frame (44) has a collar (54) which, in the operating position, overlaps an edge section (56) of the housing opening (52).

6. Air filter according to one of the preceding claims, wherein the filter medium body (22) has a circumferentially closed opening (32) extending from the first side (24) to the second side (26), and wherein the sealing body (34) closes the opening (32).

7. Air filter according to claim 6, wherein the filter medium body (22) has a bellows in which the opening (32) is formed, in particular wherein the opening (32) is sealed by at least one bead of glue (33).

8. Air filter according to one of the preceding claims, wherein the sealing body (34) forms a cap (40) with a circumferentially enclosed cavity (42) open towards the first side (24), in particular wherein the cavity (42) extends beyond the second side (26), and wherein the support finger (60) engages in the cavity (42) from the first side (24), in particular wherein the support finger (60) extends beyond the second side (26) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

9. Air filter according to claim 8, wherein the cap (40) has at least one radially outward projection (88), and wherein the support finger (60) has a radially outwardly projecting rib (96) which engages in the projection (88) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

10. Air filter according to claim 8 or 9, wherein the support element (74) has a projection (98) which partially surrounds the cap (40) of the sealing body (34) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12), in particular wherein the projection (98) extends around the cap (40) over an angular range of at least 60° and / or at most 180°.

11. Air filter according to one of claims 10, wherein the extension (98) of the support element (74) and the support finger (60) overlap each other along the main flow direction (28) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

12. Air filter according to one of the preceding claims, wherein the sealing body (34) has a flange (94) at the open end of the cap (40), and wherein the support finger (60) has a shoulder (92) which rests against the flange (94) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

13. Air filter according to one of the preceding claims, wherein the support element (74) has an end face (76) which rests against the sealing body (34) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

14. Air filter according to claim 13, wherein the sealing body (34) has a central recess (78) at the bottom (80) of which the end face (76) of the support element (74) rests when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

15. Air filter according to any one of the preceding claims, wherein the sealing body (34) has a projection (70) extending towards the first side (24), and wherein the support finger (60) has a central recess (64) at its axial end (62) facing the sealing body (34), into which the projection (70) engages when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

16. Air filter according to any one of the preceding claims, wherein the support finger (60) has a rim (66) at its axial end facing the sealing body (34), which bears against a vertex surface (72) of the sealing body (34) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

17. Air filter according to one of the preceding claims, wherein the sealing element (34) is arranged eccentrically on the filter medium body (22).

18. Air filter according to one of the preceding claims, wherein several sealing elements (34) are arranged on the filter medium body (22) within the area enclosed by the seal (30), in particular wherein the sealing elements (34) are offset from one another transversely to an insertion direction (87) of the flat filter element (20) held in the frame (44), wherein the frame (44) has a support finger (60) for each sealing element (34) which engages in the filter medium body (22) from the first side (24) and is supported on the respective sealing element (34) when the frame (44) with the flat filter element (20) is in a service position in the housing (12), and wherein the housing (12) has a support element (74) for each sealing body (34) which is supported on the sealing body (34) when the frame (44) with the flat filter element (20) is in the operating position in the housing (12).

19. Flat filter element (20), in particular for an air filter (10) according to one of claims 1 to 18, comprising a filter medium body (22) and a circumferential seal (30) that surrounds the filter medium body (22) on the outside, wherein the filter medium body (22) has a first side (24) and a second side (26) which face away from each other and which extend transversely to a main flow direction (28), and wherein a sealing element (34) for the attachment of a support finger (60) engaging in the filter medium body (22) from the first side (24) is arranged on the filter medium body (22) within the area enclosed by the seal (30).

20. Flat filter element according to claim 19, wherein several sealing bodies (34) are arranged on the filter medium body (22) within the area enclosed by the seal (30), which are offset from one another transversely to a longitudinal direction of the filter medium body (22), in particular offset from one another along folded edges (31) of the filter medium body (22), and which each close a circumferentially closed opening (32) which extends in the filter medium body (22) from the first side (24) to the second side (24).

21. Housing arrangement for an air filter according to one of claims 1 to 18, comprising a housing (12) and a frame (44) that can be inserted into the housing (12) for receiving a flat filter element (22).

22. Frame (44) for an air filter (10) according to one of claims 1 to 18.

Images