Air filter element and method for manufacturing the same

Abstract

The present invention relates to an air filter element (100), comprising: a filter medium package (110) including a filter medium, the filter medium package having a first side (111) and a second side (112) of optional substantially planar shape, the first side (111) and the second side (112) being optionally parallel; and a guide edge (120) including a sealing surface having at least radially oriented portions disposed on at least one of the first side (111) and the second side (112); wherein the outer periphery of the guide edge or each guide edge includes at least one protruding portion and at least one recessed portion; and wherein the contour of the filter medium package (110) corresponds to at least a portion of the protruding portion and the recessed portion of the guide edge. The present invention also relates to a method for manufacturing an air filter element.

Description

[0001] Related Applications

[0002] This application was filed as a PCT international application on October 24, 2017, and claims priority to European Patent Office patent application serial number EP16195388.0, entitled “AIR FILTER ELEMENT AND METHOD FOR PRODUCINGSAME”, filed on October 24, 2016, which is incorporated herein by reference in its entirety. Technical Field

[0003] The invention relates to an air filter element and a method for producing an air filter element. Background Art

[0004] U.S. Patent No. 9,162,172 B2 discloses an air filter including a housing and an inspection cover. The interior space of the housing can be reached through an opening in the side wall of the housing. A filter element having a fluted filter medium can be removed from the air filter and replaced. The housing is constructed and arranged so that the element is in sealing engagement with the housing. A method of installing a filter element in an air filter includes sliding a portion of the filter element relative to a sliding surface in the housing. A method of repairing / maintaining the air filter includes tilting the filter element relative to an inclined surface in the housing to release the seal between the filter element and the housing. The filter element may have a handle to assist in the repair / maintenance of the air filter. The housing may have an inspection window to allow visual inspection of the internal components of the housing and visual determination of whether the filter element is installed therein.

[0005] It has been found that the sealing of filter elements of the type disclosed in U.S. Pat. No. 9,162,172 B2 is sometimes unsatisfactory. It has also been found that the generally shaped housing disclosed in U.S. Pat. No. 9,162,172 B2 may, in certain circumstances, allow incorrect insertion of a filter element and intentional or unintentional replacement of a suitable filter element with an inappropriate filter element, which may result in malfunction of the air filter system and even damage to systems downstream of the air filter system.

[0006] U.S. Patent No. 9,205,361 B2 discloses an air filter element for an air filter, which has a tubular filter medium, whose annular cross section surrounds the interior of the filter element and has an inner wall adjoining the interior of the filter element and extending in the form of at least one convex arch and at least two concave arches, wherein the concave arch is located between the two convex arches, so that the interior of the filter element has a constriction in the area of ​​the concave arch, which is adjoined by two wide areas of the interior of the filter element. This disclosure does not involve a fluted filter medium, nor does it involve the above-mentioned problems in the content of U.S. Patent No. 9,162,172 B2.

[0007] German patent application publication number DE 10 2015 016236 A1 discloses a filter element comprising a plurality of superimposed blades which are implemented in an uneven manner and have at least one curvature and are interconnected in their curved state, wherein the axis of the curvature is parallel to the flow channel. The filter element of DE 10 2015 016236 A1 does not have a leading edge with a sealing surface which is arranged to provide a radial seal when installed in a target housing. The filter medium of the filter element of DE 102015 016236 A1 does not have a tubular shape.

[0008] European patent application publication number EP 1 656 982 A1 discloses a composite filter construction comprising a first open-cell foamed polyurethane layer, an intermediate layer comprising polyester fibers and polypropylene microfibers, a second layer connected to the intermediate layer comprising a non-woven polypropylene fabric material, and a polyurethane material gasket co-molded on the layers. The filter construction of EP 1 656 982 A1 does not have a leading edge with a sealing surface, the sealing surface being arranged to provide a radial seal when installed in a target housing. The filter medium of the filter construction of EP 1 656 982 A1 does not have a tubular shape.

[0009] German patent application publication number DE 10 2014 016908 A1 Figure 8 and 9A filter element for a fluid, in particular for an internal combustion engine, in particular for a motor vehicle, is disclosed, comprising a filter bellows made of a filter medium, which is placed in the filter bellows along a fold edge, in particular in a zigzag shape in the fold, extending between opposite face edges of the filter bellows, wherein face folds with fold edges and opposite free face boundaries are provided on each opposite end face of the filter bellows and at least two fold edges, the at least two fold edges being continuous along the face edges of the fold ends at opposite surfaces of the filter bellows, wherein at least a portion of one face edge extends at an angle relative to at least one of the fold edges, so that in said portion, the fold edge on one surface has a different length than the fold edge on the other surface, and wherein the fold is sealed transversely by the face edge. The cited embodiments do not have a guide edge with a sealing surface, which is arranged to provide a radial seal when installed in a target housing. The filter medium of these embodiments does not have a tubular shape.

[0010] European patent application publication number EP 2 675 547 A1 discloses an air filter system, including a filter housing, in which a filter element is contained. The filter element includes a pleated filter medium. A second housing is fixed to the filter housing and closes the filter housing. The second housing includes a locking element operable to engage the filter housing and the filter element. The filter element includes at least one fastening element, wherein the locking element of the second housing engages at least one fastening element so that when the filter element is contained in the filter housing and is disposed between the filter housing and the second housing, the second housing is removably clamped / fixed to the filter housing. The document does not disclose a guide edge including a sealing surface, and the sealing surface has at least a radially oriented component. Summary of the invention

[0011] It is an object of embodiments of the present invention to provide a filter element with improved sealing properties.It is another object of embodiments of the present invention to reduce the risk of incorrect installation of the filter element in a filter system.

[0012] According to one aspect of the present invention, an air filter element is provided, comprising: a filter media pack, the filter media pack comprising filter media, the filter media pack having a first and a second side, the first and the second sides being optionally arranged as a first side of a basic plane and a second side of a basic plane, the first side and the second side being optionally parallel; and a guide edge comprising a sealing surface, the sealing surface having at least a radially oriented component, arranged on at least one of the first side and the second side; wherein the periphery of the guide edge or each guide edge comprises at least one raised portion and at least one recessed portion; and wherein the contour of the filter media pack corresponds to at least a portion of the raised portion and the recessed portion of the guide edge.

[0013] The invention is based in particular on the inventors' insight that by providing the filter element with a leading edge having a sufficiently curved periphery, in particular a periphery having at least one raised portion and at least one recessed portion, a more reliable seal can be obtained than when a seal is formed along a substantially straight line. The leading edge comprises a sealing surface having at least radially oriented components; in particular, the leading edge may comprise a radially oriented seal (also referred to as a radial seal).

[0014] The present invention is based on the further insight of the inventors that by providing the filter element with a leading edge having at least one raised portion and at least one recessed portion at its periphery, the overall symmetry of the filter element can be reduced, thereby reducing the likelihood of incorrect installation of the filter element in the housing.

[0015] The present invention is also based on the inventors' further insight that by having a filter media pack whose contour corresponds to the periphery of the leading edge at least in the raised portion, the space defined by the leading edge is optimally used to provide filtering capacity. The term "corresponding to" is used herein to indicate that the shape of the filter media pack closely follows the shape of the leading edge; the distance between the contour of the filter media pack and the leading edge is relatively small and does not vary significantly along the contour. Along the raised portion of the periphery, the leading edge preferably remains within a distance of 2 cm, more preferably within a distance of 1 cm, and most preferably within a distance of 0.5 cm of the contour of the filter media pack. Along said raised portion of the periphery, the distance between the leading edge and the contour of the filter media pack preferably does not vary by more than 2 cm, more preferably by no more than 1 cm, and most preferably by no more than 0.5 cm. Alternatively, the periphery of the leading edge may correspond to the contour of the filter media pack over its entire length, i.e. not only on the raised portion.

[0016] Another advantage of a filter media pack having a profile with a recessed portion is that the hollow space formed thereby is very suitable for accommodating a handle for facilitating installation or removal of the filter element.

[0017] The sealing surface having at least a radially oriented component is preferably arranged to provide a radial seal when mounted in a suitably shaped cavity.

[0018] The filter media pack preferably has a tubular shape. The term "substantially tubular" is used to cover shapes obtained by winding a length of filter media (with or without a core or hollow space in the center), shapes obtained by arranging pleated filter media as a tube, and shapes obtained by combining multiple units that are substantially tubular in the above sense. The substantially tubular shape may include one or more constrictions and / or bends.

[0019] In one embodiment of an air filter element according to the invention, the filter media pack comprises a rolled-up length of filter media having a tubular shape and a core that is substantially geometrically similar to the profile.

[0020] An advantage of this embodiment is that relatively complex contours can be obtained by winding the filter media around a properly designed core. The filter media can be wound around a winding core, removed from the winding core, and then the final core is set. Alternatively, the filter media can be wound around a core that remains in place in the final product. Another advantage of this embodiment is that it provides increased rigidity. The term "geometrically similar" is used herein to refer to objects having the same overall shape but different proportions. The term "substantially geometrically similar" is used to indicate that the similarity in the shapes of the core and the leading edge does not need to be exact, but is strong enough for the core to determine the shape of the resulting wound package.

[0021] In one embodiment of the air filter element according to the invention, the filter media pack comprises a z-type filter media.

[0022] In this type of construction, the inlet and outlet surfaces of the filter media are parallel, substantially planar sides wherein the ends of the "flutes" of the media are aligned.

[0023] In one embodiment of the air filter element according to the invention, the filter media pack comprises pleated filter media arranged in a tubular shape.

[0024] In this type of structure, the inlet and outlet surfaces of the filter media are typically inner covers of the tubular shaped apertures and outer covers of the tubular shaped apertures, or vice versa. Although the filter media pack has a substantially planar first side and a substantially planar second side, the first side and the second side are parallel, as described above, the pleated filter media can be arranged in different shapes (e.g., W-shaped) within the filter media pack.

[0025] In one embodiment of the air filter element according to the present invention, the profile is elongated and there is at least one concave portion along the longitudinal side of the profile. More specifically, the profile can be substantially bean-shaped or kidney-shaped. The filter element then has a bean-shaped type or a kidney-shaped type.

[0026] An advantage of this embodiment is that a degree of asymmetry can be introduced into the design with minimal additional complexity.

[0027] In one embodiment of the air filter element according to the invention, the filter media pack comprises at least two individually wound lengths of filter media, which are joined together by a leading edge. More specifically, the profile may be substantially 8-shaped. The filter element then has a figure-of-8 or double-twisted shape.

[0028] This embodiment is based, among other things, on the inventors' insight that the filter media pack may advantageously be in a figure-eight shape or the like. One advantage of this embodiment is that the individual rolls may be cylindrical and may be obtained simply by winding a media sheet around a cylindrical core or winding a media sheet around itself, while the combination of several rolls still results in the desired profile with concave and convex portions. Each of the at least two individually wound lengths of filter media may include a cylindrical core (either the winding core around which it is wound, or a different core inserted after the roll is removed from the winding core), or it may be coreless.

[0029] In one embodiment of the air filter element according to the invention, the filter medium pack is wound so as to leave no hollow space in its center.

[0030] In one embodiment, the filter media pack is rolled or coiled such that the filter media pack has no hollow space at the center thereof.

[0031] Since filter media packs composed of certain types of filter media (e.g., fluted or z-type filter media) do not require a tubular shape in order to supply air or extract air from a hollow center (as is the case with the pleated media example disclosed in the above-referenced U.S. Patent No. 9,205,361 B2), the filter media pack can advantageously be completely filled with filter media, thereby increasing the filtration capacity of a given housing space. The "full" filter media pack can be obtained by winding the filter media around a removable winding core and flattening it after it is removed from the roll. Alternatively, the "full" filter media pack can be obtained by winding a sheet of filter media onto itself.

[0032] According to one aspect of the present invention, an air filter system is provided, comprising a housing and an air filter element, wherein the air filter element has a substantially bean-shaped or kidney-shaped profile as described above, wherein the housing defines a cavity shaped so as to be able to accommodate the air filter element; wherein the housing includes an inspection window for inserting the air filter element into the cavity and removing the air filter element from the cavity; and wherein the inspection window is shaped and arranged so that the air filter element can be inserted and removed by a movement including rotation.

[0033] A particular advantage of a filter element with a "bean-shaped" or "kidney-shaped" profile is that the filter system can occupy available space in a system that would otherwise not accommodate a filter system of conventional shape (particularly, a cavity with a bend or corner). In addition, the air filter element can be introduced and removed in a non-axial direction. In addition, the air filter element can be moved toward or away from the housing along a path between obstacles, such as pre-set components of an engine or machine, which is not possible with a standard straight filter element.

[0034] In the case described, the housing may be adapted to introduce and remove the filter element from the side (i.e., laterally rather than axially along the flow direction of the air to be filtered), in which case a relatively small side opening may be sufficient to allow the filter element to rotate and slide in or out of the housing. The rotational motion allows the bean-shaped or kidney-shaped air filter element to rotate "around a corner" during installation or removal. Such a corner may exist because the housing may have to be arranged in a part of a machine or engine system, where the presence of other necessary components does not leave room for a large straight filter chamber. The bean-shaped or kidney-shaped air filter element can be bent around an obstacle and can still be inserted or removed relatively easily. Therefore, obstacles such as components of a predetermined engine setting (e.g., the setting of engine components under the hood of a car or truck) may exist in the space defined by the concave portion of the filter media pack profile during the insertion or removal track of the filter media pack. In some embodiments, the inspection window is shaped and arranged so that, considering the shape of the air filter element, the air filter element can only be inserted and removed by a motion including rotation, for example, following the curvature of the profile. More complex shapes having two or more recessed portions along the contour of the filter media pack may be used to allow the filter element to travel through more complex obstacle combinations.

[0035] The sealing surface of the air filter element preferably provides a radial seal against the housing. In some examples, the sealing surface faces away from the longitudinal axis of the filter element and can therefore be characterized as an outwardly facing seal or an outwardly directed radial seal.

[0036] According to one aspect of the present invention, a method for manufacturing an air filter element is provided, the method comprising: winding at least a length of filter media having a constant width to produce a filter media pack having a first substantially planar side and a second substantially planar side, the first side and the second side being parallel; and providing a guide edge including a sealing surface on at least one of the first side and the second side, the sealing surface having at least one radial component; wherein the outer periphery of the guide edge or each guide edge comprises at least a raised portion and at least a recessed portion; and wherein the contour of the filter media pack corresponds to at least a portion of the raised portion and the recessed portion of the guide edge.

[0037] The filter medium preferably has a substantially tubular shape.The sealing surface is preferably arranged to provide a radial seal when mounted in a suitably shaped cavity.

[0038] In one embodiment of the method according to the invention, the winding comprises winding the length of filter medium around a core having a shape substantially geometrically similar to the periphery.

[0039] In a particular embodiment, the profile is elongated and there is at least one concave portion along a longitudinal side of the profile. More specifically, the profile may be substantially bean-shaped or kidney-shaped.

[0040] In one embodiment of the method according to the invention, the winding comprises winding at least two wound lengths of filter medium respectively around respective cylindrical cores and connecting the two individually wound lengths of filter medium together by providing a leading edge. More specifically, the profile may be substantially figure-eight shaped.

[0041] In one embodiment of the method according to the invention, the winding comprises winding a length of filter media around a core, the method further comprising removing the core from the filter media pack and deforming the filter media pack to obtain the profile.

[0042] In one embodiment, an air filter element is provided with a filter media pack, a first guide edge, and a sealing portion. The filter media pack can be formed of a coiled fluted filter media and can have an outer periphery defining a raised portion and a recessed portion. The first guide edge can be mounted to a first end of the filter media pack. The first guide edge can also define a raised portion corresponding to the raised portion of the filter media pack and a recessed portion corresponding to the recessed portion of the filter media pack. The sealing portion can be supported by the first guide edge and can define an outwardly directed radial sealing surface. The first guide edge can also define recessed and raised portions.

[0043] In one embodiment, the second leading edge is mounted to the second end of the filter media pack.

[0044] In one embodiment, the first leading edge and the filter media pack each have two raised portions and two recessed portions.

[0045] In one embodiment, the filter media pack further includes a central core.

[0046] In one embodiment, the filter media pack has a cross-sectional shape characterized as a kidney shape, a bean shape, a lemniscate shape, or one of a figure 8 shape, an S shape, and a W shape.

[0047] The technical effects and advantages of the embodiments of the method according to the invention correspond mutatis mutandis to those of the corresponding embodiments of the filter element according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] These and other features and advantages of embodiments of the present invention will be described in more detail in conjunction with the accompanying drawings, in which:

[0049] - Figure 1 shows a perspective view of a filter element according to a first embodiment of the present invention;

[0050] - Figure 1a Shows Figure 1 An end view of the filter element shown in;

[0051] - Figure 1b Shown along Figure 1a The line AA in Figure 1 A cross-sectional view of the filter element shown in ;

[0052] - Figure 2 Shown according to Figure 1 An exploded view of a filter element of an embodiment of the invention;

[0053] - Figure 3 Schematically shows the Figure 1 Embodiments of a first method of manufacturing a filter element;

[0054] - Figure 4 , Figure 4a , Figure 4b Schematically shows the Figure 1 Embodiments of the second method of manufacturing a filter element;

[0055] - Figure 5 shows a perspective view of a filter element according to a second embodiment of the present invention;

[0056] - Figure 5a Shows Figure 5 An end view of the filter element shown in ;

[0057] - Figure 5b Shown along Figure 5a The line AA in Figure 5 A cross-sectional view of the filter element shown in ;

[0058] - Figure 6 Shown according to Figure 5 An exploded view of a filter element of an embodiment of the invention;

[0059] - Figure 7 shows a perspective view of a filter element according to a third embodiment of the present invention;

[0060] - Figure 7a Shows Figure 7 An end view of the filter element shown in ;

[0061] - Figure 7b Shown along Figure 7a The line AA in Figure 7 A cross-sectional view of the filter element shown in ;

[0062] - Figure 8 Shown according to Figure 7 An exploded view of a filter element of an embodiment of the invention;

[0063] - Fig. 9 shows a perspective view of a filter element according to a fourth embodiment of the present invention;

[0064] - Figure 9a Shows Fig. 9 An end view of the filter element shown in ;

[0065] - Figure 9b Shown along Figure 9a The line AA in Fig. 9 A cross-sectional view of the filter element shown in ;

[0066] - Fig.10 Shown according to Fig. 9 An exploded view of a filter element of an embodiment of the invention;

[0067] - Figure 11-11a Schematically shows the Fig.10 Embodiments of the method of manufacturing a filter element;

[0068] - Fig.12 shows a first perspective view of an air filter system including an air filter element according to an embodiment of the present invention;

[0069] - Fig.12a Shows Fig.12 A second perspective view of the air filter system shown in ;

[0070] - Fig.13 Shows Fig.12 A first perspective view of an air filter element shown in ;

[0071] - Fig.13a Shows Fig.13 A second perspective view of the air filter element shown in ;

[0072] - Fig.14 is a schematic diagram of examples of shapes of filter media packs that may be included in embodiments of the present invention;

[0073] - Fig.15 is a schematic diagram of another example of a shape of a filter media pack that may be included in embodiments of the present invention;

[0074] - Fig.16 is a schematic diagram of another example of a shape of a filter media pack that may be included in embodiments of the present invention; and

[0075] - Fig.17 is an outline of another example of a shape of a filter media pack that may be included in embodiments of the present invention. DETAILED DESCRIPTION

[0076] Now combine Figure 1-4A first embodiment of a filter element according to the present invention will be described.

[0077] Figure 1-1b A plan view (upper left), a cross-sectional view (lower left), and a perspective view (right) of this embodiment are shown, respectively.

[0078] The illustrated air filter element 100 comprises a filter media bag 110, and the filter media bag 110 comprises a filter media of a winding length. The filter media bag 110 has a substantially planar first side 111 and a substantially planar second side 112, which are parallel to each other. The air filter element 100 is intended to be removably installed in a housing (not shown). In order to allow the air filter element 100 to be inserted or removed, the housing has one or more openings or "windows". Various housings and window arrangements are possible, including a system in which an opening is entered by removing the end of the housing provided with an inlet or outlet, and a system in which the window on the housing side can be entered. For the filter media bag design with an elongated profile, a "side loader" can have its window positioned at a narrow side or positioned at a wide side.

[0079] The present invention can be implemented with different types of filter media, including pleated filter media and fluted filter media. Various types of pleated filter media are commercially available and known to the skilled artisan. Fluted filter media includes a filter material having a plurality of flutes formed therein, with alternating ends of adjacent flutes closed to force fluid through the filter material. Various types of fluted filter media are commercially available and known to the skilled artisan.

[0080] Filter media packs of the fluted filter media type or z-type media are known to the skilled person. For example, certain types of fluted filter media can be known from U.S. Pat. No. 3,025,963 to Jordan V. Bauer, U.S. Pat. No. 5,895,574 to Francis Friedmann et al., U.S. Pat. No. 6,416,605 to Patrick Golden, and from U.S. Patent Application Publication No. US 2014 / 0102057 A1. The entire contents of each of the US'574 patent, the US'605 patent, and the US'057 disclosure are hereby incorporated herein by reference in their entirety. A filter media pack 110 of the fluted filter media type can be obtained, for example, by winding a base sheet comprising substantially parallel hollow tubes (flutes, original tubes) and applying a sealing adhesive between successive layers of the wound filter media (e.g., on one side of the open end). The base sheet can, for example, consist of a flat media sheet and a corrugated media sheet, which are connected to each other. The first axial end of the hollow tube abuts the first substantially planar side 111 of the filter media pack 110, and the second axial end of the hollow tube abuts the second substantially planar side 112 of the filter media pack 110. When the base sheet is wound, complementary spaces / tubes can be formed between the hollow tubes and defined between a wound corrugated sheet and a subsequently wound planar sheet.

[0081] The hollow tube and the complementary space / tube can be interrupted at appropriate locations to force the air entering the first tube (e.g., the original tube) at its first axial end (at the first plane side 111) to pass through the side wall of the first tube into one or more adjacent second tubes (e.g., complementary tubes), and thereafter force the air to leave the second tube at the second axial end of the second tube (at the second plane side 112). Some of these interruptions can be initially set by the original tube (e.g., closed at their second axial ends), and other interruptions can be set, for example, by applying a sealing adhesive (e.g., for complementary tubes, preferably near their first axial ends). The ends 111, 112 are then used as the outlet and inlet surfaces of the filter. When the filter element 100 is installed in the housing of the filter system of which it forms a part, the air is preferably but not necessarily supplied to the inlet surface and evacuated from the outlet surface via a pre-cleaning filter, which may include multiple cyclone separators.

[0082] Likewise, other types of filter media packs 110 may be obtained by including a step of winding a media provided in sheet form.

[0083] Air filter element 100 also comprises a guide edge 120 arranged on at least one of said first side 111 and said second side 112.Preferably, guide edge 120 is present on both sides 111,112, as shown in the figure.At least one described guide edge 120 comprises a radially oriented sealing surface or a sealing surface with at least radially oriented parts, for example outward radially oriented parts.In addition, it can have an axial component.It can be provided with a gasket, as a radial seal or an axial seal with at least a radial component.

[0084] The guide edges 120 provide sealing surfaces that allow the filter element 100 to sealably engage with the inlet and / or outlet holes of the filter system. In addition, they can contribute to the structural rigidity of the filter element 100, and they can help the operator to correctly place the filter element 100 in the filter system (by virtue of their shape, and optionally by means of added guide elements such as protrusions, grooves, lugs, etc.).

[0085] The leading edge 120 may comprise a rigid plastic material 120a (which may be, for example, a support structure), such as but not limited to polyethylene or polypropylene, with a separate seal or gasket 120b made of, for example, a suitable elastomer, or polyurethane disposed on their sealing surfaces. Alternatively, the leading edge 120 may be made of a material that can act as a seal, in particular a suitable elastomer, such as polyurethane.

[0086] The leading edges 120 may be fabricated separately and attached to the filter media pack 110, or they may be molded in place (ie, overmolded onto the filter media pack 110) if the melting and solidification characteristics of the selected material permit.

[0087] In the illustrated case, the air filter seen in the plan view has an elongated shape. The periphery of each guide edge 120 includes at least one raised portion and at least one recessed portion. In conjunction with the direction of the plan view for the current purpose, it can be clearly seen in the illustrated case that the left-hand side 120c and the right-hand side 120d of the profile are raised (observed from the outside of the filter element), while the top side 120e and the bottom side 120f (longitudinal side) of the profile include recessed central portions 120e, 120f. In the illustrated case, the profile of the filter media pack 110 (as seen in a cross section in any plane parallel to the planar sides 111, 112) corresponds to (that is, it closely matches) the entire periphery of the guide edge 120.

[0088] Figure 2 An exploded view of a filter element according to a first embodiment is shown. The filter media pack 110 has a tubular shape, ie a shape that is closed on itself around a hollow center, and comprises a core 130 that is substantially geometrically similar to the outer contour of the filter media pack 110 . Figure 2Shown are leading edges 120 on each side of the filter media 110 and a core 130 to be placed in the center of the filter media 110. The leading edges may be included in an element 125 covering a portion of the relevant side 111 or 112, for example to avoid telescopic deformation of the wound filter media pack 110; the element 125 may also help keep the core 130 in place for added structural rigidity.

[0089] Figure 3 Schematically illustrate the first method of manufacturing filter element 100 according to the first embodiment.Described method comprises winding a filter medium of a length with constant width, to produce the filter medium bag 110 with the first side 111 of basic plane and the second side 112 of basic plane, and described first side 111 and second side 112 are parallel.Coiling comprises the filter medium of described length winding around core 130, and described core 130 has the shape that is basically geometrically similar to the desired periphery.In order to realize sufficiently close winding, sheet material is maintained under suitable tension force and is pressed on core 130 and subsequently pressed on the bag of increase by the reciprocating roller 151-154 of suitable arrangement.Binder (not shown) is applied on sheet material to keep continuous layer together.

[0090] Once the desired shape and size of the filter media pack 110 is obtained, the leading edge 120 as described above is disposed on the first side 111 and the second side 112 ( Figure 3 at least one of (not shown).

[0091] Figure 4-4b A second method of producing a filter element according to the first embodiment is schematically illustrated.

[0092] In a preliminary step (not shown), a length of filter media having a constant width is wound around an oval or oblong winding core to produce a filter media pack 110 having a substantially planar first side 111 and a substantially planar second side 112, the first side 111 and the second side 112 being parallel. Since the winding core is oval or oblong, the tensioning and compression of the filter media sheet is not as good as that of a conventional winding core. Figure 3 The situation shown in is complicated. During the winding operation, an adhesive is applied to the sheet to hold the successive layers together. After removal from the winding core, the resulting filter media pack 110 has an elongated shape without concave portions and a hollow center.

[0093] In a first step 1010, a core 130 representing a desired contour shape substantially similar thereto in geometry is inserted into the hollow center of the filter media pack 110. In a second step 1020, the filter media pack 110 with the core 130 is placed into a suitably shaped press mold 160 having protrusions corresponding to the desired recessed portions of the contour. In a third step 1030, the press mold 160 is closed to force the filter media pack 110 into the desired shape. Since this deformation inevitably results in some slippage of the filter media layers in the filter media pack 110, this step should preferably be completed before the applied adhesive has fully cured.

[0094] In a subsequent step (not shown), a guide edge 120 as described above is provided on at least one of the first side 111 and the second side 112 .

[0095] Now combine Figure 5 and 6 A second embodiment of the filter element according to the invention will be described. This embodiment will be described focusing on the elements that are different from those of the first embodiment.

[0096] Figure 5-5b A plan view (upper left), a cross-sectional view (lower left), and a perspective view (right) of this embodiment are shown.

[0097] The air filter element 100 shown includes a filter media pack 110, which includes two individually wound lengths of filter media. The resulting filter media pack 110 has a substantially planar first side 111 and a substantially planar second side 112, which are parallel to each other. As previously mentioned, the filter media is preferably of the "fluted filter media" type.

[0098] The air filter element 100 further comprises a leading edge 120 disposed on at least one of the first side 111 and the second side 112. Preferably, the leading edge 120 is present on both sides 111, 112, as is the case in the figure. Since the filter media pack 110 shown consists of two individually wound lengths of filter media, the leading edge 120 has the additional function of holding the two rolls together to form one pack.

[0099] In the illustrated case, the air filter element 100 has an elongated shape. The periphery of each guide edge 120 includes at least one raised portion and at least one recessed portion. In conjunction with the direction of the plan view for the present purpose, it can be clearly seen in the illustrated case that the left-hand side 120c and the right-hand side 120d of the profile are raised (observed from the outside of the filter element), while the top side 120e and the bottom side 120f (longitudinal side) of the profile include recessed central portions 120e, 120f. In the illustrated case, the profile of the filter media pack 110 corresponds to (that is, it closely matches) the raised portion of the periphery of the guide edge 120. However, since the recessed portions 120e, 120f are located at the position where two media rolls meet each other, the profile of the filter media pack 110 does not strictly follow the periphery of the guide edge 120 in these parts.

[0100] Figure 6 An exploded view of a filter element according to a second embodiment is shown. The filter media pack 110 consists of two tubular cylinders, i.e. a cylinder with a hollow center, and includes a corresponding cylindrical core 130. FIG. 6 also shows a leading edge 120 on each side of the filter media 110, which holds the roll of filter media 110 together and places the core 130 in the center of the roll of filter media 110.

[0101] Now combine Figures 7 and 8 A third embodiment of the filter element according to the present invention is described. This embodiment will be described focusing on the elements that are different from those of the first embodiment.

[0102] Figure 7-7b A plan view (upper left), a cross-sectional view (lower left), and a perspective view (right) of this embodiment are shown, respectively.

[0103] The air filter element 100 shown comprises a filter media pack 110 comprising a coiled length of filter media. The filter media pack 110 has a substantially planar first side 111 and a substantially planar second side 112, which are parallel to each other. The filter media is again preferably of the "fluted filter media" type.

[0104] The air filter element 100 further comprises a guide edge 120 arranged on at least one of the first side 111 and the second side 112. Preferably, the guide edge 120 is present on both sides 111, 112, as is the case in the figures.

[0105] In the illustrated situation, air filter element 100 has an elongated shape. The periphery of each leading edge 120 comprises at least one raised portion and at least one recessed portion. In conjunction with the direction of the plan view for the present purpose, in the illustrated situation, it can be clearly seen that the left-hand side 120c and the right-hand side 120d of the profile are convex (observed from the outside of the filter element), and the top side 120e of the profile is straight, and the bottom side 120f of the profile comprises a recessed center portion 120f. In the illustrated situation, the profile of filter media pack 110 corresponds to the whole periphery of (that is, it closely matches) leading edge 120.

[0106] Figure 8 An exploded view of a filter element according to a first embodiment is shown. The filter media pack 110 has a tubular shape, ie a shape which is closed on itself around a hollow center, and comprises a core 130 which is substantially geometrically similar to the outer contour of the filter media pack 110 . Figure 8 Leading edges 120 on each side of the filter media 110 and a core 130 to be placed in the center of the filter media 110 are shown.

[0107] Now combine Figure 9-11 A fourth embodiment of the filter element according to the present invention will be described. This embodiment will be described focusing on the elements that are different from those of the first embodiment.

[0108] Figure 9-9b A plan view (upper left), a cross-sectional view (lower left), and a perspective view (right) of this embodiment are shown, respectively.

[0109] The air filter element 100 shown comprises a filter media pack 110 comprising a coiled length of filter media. The filter media pack 110 has a substantially planar first side 111 and a substantially planar second side 112, which are parallel to each other. The filter media is again preferably of the "fluted filter media" type.

[0110] The air filter element 100 further comprises a guide edge 120 arranged on at least one of the first side 111 and the second side 112. Preferably, the guide edge 120 is present on both sides 111, 112, as is the case in the figures.

[0111] In the illustrated situation, air filter element 100 has an elongated shape. The periphery of each leading edge 120 comprises at least one raised portion and at least one recessed portion. In conjunction with the direction of the plan view for the present purpose, in the illustrated situation, it is clear that the top side 120e, left-hand side 120c and right-hand side 120d of the profile are convex (observed from the outside of the filter element), and the bottom side 120f of the profile comprises a recessed center portion 120f. In the illustrated situation, the profile of filter media pack 110 corresponds to the whole periphery of (that is, it closely matches) leading edge 120.

[0112] Fig.10 An exploded view of a filter element according to a first embodiment is shown.The filter media pack 110 is fully filled, ie it has no hollow centre and in this case no core. Fig.10 Also shown are leading edges 120 on each side of the filter media 110 .

[0113] Figure 11-11a A method for producing a filter element according to a fourth embodiment is schematically shown.

[0114] In a preliminary step (not shown), a length of filter media having a constant width is wound around a cylindrical winding core to produce a filter media pack 110 having a substantially planar first side 111 and a substantially planar second side 112, the first side 111 and the second side 112 being parallel. Since the winding core is cylindrical, the tensioning of the filter media sheet is not as good as that of the winding core. Figure 3 The situation shown is complex. During the winding operation, an adhesive is applied to the sheet material to hold the successive layers together. After removal from the winding core, the resulting filter media pack 110 has a cylindrical shape without concave portions and a hollow center.

[0115] In a first step 2010, a filter media pack 110 having a hollow center is placed into an appropriately shaped press mold 160 having protrusions and cavities corresponding to the desired contour shape. In a second step 2020, the press mold 160 is closed to force the filter media pack 110 into the desired shape. Since this deformation inevitably results in some slippage of the filter media layers in the filter media pack 110, this step should preferably be completed before the applied adhesive has fully cured.

[0116] In a subsequent step (not shown), a guide edge 120 as described above is provided on at least one of the first side 111 and the second side 112 .

[0117] Fig.12 and 12a Two perspective views of an air filter system including an air filter element according to an embodiment of the invention are shown. Fig.13 and13a Shows Fig.12 and 12a Two perspective views of an air filter element of an air filter system shown in FIG. Without loss of generality, Fig.12 , 12a The air filter element shown in Figures 13 and 13a has a coreless kidney-shaped or bean-shaped filter media pack 110. At one end, a guide edge 120 with a sealing surface is provided. At the other end, a handle 170 is provided across the recessed portion of the profile. The handle can be obtained very simply by providing a strip or strip of material bridging the recessed portion of the profile, so that a manual operator can easily grasp the handle by sliding a finger into the cavity behind the handle. The handle can be flexible and connected after the filter element is manufactured. For example, it can be bonded to the outside of the media pack or to its outer protective layer in the recessed portion. In fact, in certain embodiments of the present disclosure, another protective layer or envelope (also referred to as a shell) of the filter media pack can be provided around its radial outer surface. The protective layer or envelope can extend over a limited distance of the media pack or over the entire length of the media pack, providing a rigid or more rigid outer shell of the media pack. The protective layer can be made of a hard material such as plastic, or, for example, made of protective cardboard. Depending on the manufacturing process, the handle can also be formed integrally with the protective envelope. Furthermore, the protective envelope or shell may be formed integrally with the guide edge or a support structure comprised in the guide edge.

[0118] As mentioned above, the filter media pack preferably has a tubular shape. The term "substantially tubular" is used to cover shapes obtained by winding a length of filter media (with or without a core or hollow space in the center), shapes obtained by arranging pleated filter media as a tube, and shapes obtained by combining multiple units that are substantially tubular in the above sense. The substantially tubular shape may include one or more constrictions and / or bends. Figure 14-17 Sketches of various substantially tubular shapes are provided in which filter media packs may be arranged in embodiments of the present invention. Since the purpose of the sketches is to illustrate the different profiles of the filter media packs and / or associated leading edges, the sketches only show solid filter media packs without a core without loss of generality. Those skilled in the art will appreciate that the shapes shown may also be obtained by combining one or more filter media units (e.g., rolls) with or without a core.

[0119] Fig.141 is a schematic diagram of an example of an air filter element 100 including a substantially tubular filter media pack 110 and including a leading edge 120, the shape of which can be described as an ellipse, which is bilaterally constricted / pinched in a direction transverse to its major axis to generally form a lemniscate, figure 8, or "peanut" shape. As shown, the periphery of the filter media pack 110 and the periphery of the leading edge 120 have two concave sections or portions interconnected by two convex sections or portions.

[0120] Fig.15 1 is a schematic diagram of an example of an air filter element 100 including a substantially tubular filter media pack 110 and including a leading edge 120, the shape of which can be described as an ellipse / oval with a single bend. As shown, the periphery of the filter media pack 110 and the periphery of the leading edge 120 have a concave section or portion interconnected by one or more raised sections or portions.

[0121] Fig.16 1 is a schematic diagram of an example of an air filter element 100 including a substantially tubular filter media pack 110 and including a leading edge 120, the shape of which can be described as having two curved ovals, generally forming an S-shape (as shown) or a Z-shape (not shown). As shown, the periphery of the filter media pack 110 and the periphery of the leading edge 120 are asymmetrically shaped, having two offset concave sections or portions interconnected by two offset convex sections or portions.

[0122] Fig.17 1 is a schematic diagram of an example of an air filter element 100 including a substantially tubular filter media pack 110 and including a leading edge 120, the shape of which can be described as having three curved ovals, generally forming a W-shape. As shown, the periphery of the filter media pack 110 and the periphery of the leading edge 120 have three concave sections or portions interconnected by three convex sections or portions.

[0123] The skilled person will appreciate that other suitable shapes may be obtained by combining any number of "contractions" and "bends" as described above into a tubular basic shape. The constrictions and bends may be arranged to form symmetrical or asymmetrical shapes.

[0124] While the present invention has been described above in conjunction with specific embodiments, this is intended to illustrate and not to limit the invention, the scope of the invention being determined by the appended claims.

Claims

1. An air filter element, comprising: - a filter media pack formed of a coiled fluted filter media, the filter media pack having an outer perimeter defining raised portions and recessed portions; - a first guide edge mounted to a first end of the filter media pack, the first guide edge defining a raised portion corresponding to a raised portion of the filter media pack and defining a recessed portion corresponding to a recessed portion of the filter media pack; and - A sealing portion supported by the first leading edge, said sealing portion defining an outwardly directed radial sealing surface.

2. The air filter element of claim 1 further comprising a second leading edge mounted to the second end of the filter media pack.

3. An air filter element according to claim 1 or 2, further comprising a shell surrounding the radially outer surface of the filter media pack.

4. The air filter element of any one of claims 1-2, further comprising a handle, the handle spanning the recessed portion of the filter media pack.

5. An air filter element according to claim 4, wherein the handle is adapted so that an operator can easily grasp the handle by sliding a finger into a cavity behind the handle.

6. The air filter element of claim 4, wherein the handle is flexible.

7. An air filter element according to any one of claims 1-2, wherein the first leading edge and the filter media pack each have two raised portions and two recessed portions.

8. The air filter element of any one of claims 1-2, wherein the filter media pack further comprises a central core.

9. The air filter element of any one of claims 1-2, wherein the filter media pack has a cross-sectional shape characterized as one of a kidney shape, a bean shape, a figure eight shape, an S shape, and a W shape.

10. The air filter element according to any one of claims 1-2, wherein the sealing portion comprises an elastomer or polyurethane.

11. The air filter element according to any one of claims 1-2, wherein along the raised portion, the distance between the first leading edge and the outer periphery of the filter media pack is maintained within 2 cm.

12. The air filter element of claim 11, wherein along the raised portion, a distance between the first leading edge and the outer periphery of the filter media pack is maintained within 0.5 cm.

13. An air filter element according to any one of claims 1-2, wherein the outer periphery of the filter media pack corresponds to the entire outer periphery of the leading edge.

14. The air filter element according to any one of claims 1 to 2, wherein the sealing portion is formed along at least one convex portion and at least one concave portion of the first leading edge.

15. The air filter element of claim 1, wherein the sealing portion is a separate component from the first leading edge.

16. An air filter element according to claim 1 or 15, wherein the first leading edge is formed of a relatively rigid material and the sealing portion is formed of a relatively resilient material.

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