Filter element and filter device
The filter element addresses construction and recyclability challenges by integrating two filter bellows with a circumferential seal and cubic geometry, enhancing mechanical stability and enabling efficient recycling.
Patent Information
- Application Number
- JP2025519599
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-04
- Filing Date
- 2023-09-07
- Publication Date
- 2025-09-29
AI Technical Summary
Existing filter elements face issues with complex construction, high material usage, high manufacturing costs, and disposal problems due to mixed materials, along with insufficient mechanical load-bearing capacity and vibration resistance, especially in multi-stage filters.
A filter element design featuring two filter bellows connected by a circumferential seal, with one bellow having a shorter length than the other, creating a free space for the seal integration, and using thermally recyclable materials, enhancing mechanical load-bearing capacity and rigidity through material bonding and a cubic geometry.
The design improves mechanical stability, facilitates efficient recycling, and reduces disposal issues while maintaining effective filtration performance, particularly in air filter systems for vehicles.
Smart Images
Figure 2025532354000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a filter element, in particular an air filter element, for an air filter system, in particular a cabin air filter system or an intake air filter system for a fuel cell, and further to a filter device comprising such a filter element.
[0002] A filter element or filter insert is generally understood to be an insert that is replaceably positioned as a unit within a filter housing and includes at least a filter medium body, often in the form of a folded filter bellows, and generally also includes a structure for supporting or carrying the filter medium, and often a seal. Each filter medium generally has a limited service life. For this reason, the filter element must be periodically replaced as a unit.
[0003] Today, the air entering the vehicle cabin is purified as thoroughly as possible of pollutants. These pollutants include, for example, particulate matter, pollen, soot, and aerosols. Filtering these pollutants is particularly important in applications where these substances are present in high concentrations in the ambient air due to the use of plant protection agents or liquid fertilizer application systems. Various filtering methods are available for this purpose. Commonly used filters include particle filters, activated carbon filters, and HEPA filters. These are combined in various layers and configurations to achieve the desired filtering effect on the interior air.
[0004] In practice, the use of multiple filter systems and filter elements is established due to the wide variety of contaminant combinations encountered that must be removed. [Background technology]
[0005] EP 3520878 A1 discloses a filter module for filtering indoor air, which includes three filter layers arranged on a common frame assembled from extruded profile strips. One of the filter layers is an adsorption filter configured as a honeycomb body, and the other two filter layers are particle filters. The particle filter layers are composed of separate filter bellows through which fluid can flow in series, one of which is made of HEPA filter material. The profile strip of the frame holds the filter layers on its inner side, while the frame seals the filter module to the housing on its outer side. The filter module also includes circumferentially extending sealing flanges formed on the profile strip that protrude radially outward in the area of the two particle filter elements. The profile strip also has two circumferentially extending collars that protrude inward and support two of the filter layers, respectively. Combining this configuration with the particle filter layers as separate filter bellows requires a relatively large axial installation space.
[0006] The drawbacks of this are the relatively complex construction, the associated high material usage and associated high manufacturing costs, and the mixed materials used make purely thermal recycling impossible, which creates disposal problems.
[0007] Furthermore, WO 2015 / 092681 discloses a filter element with two filter bellows, each made of a cellulose-based filter material, that can flow in series. The two filter bellows are adjacent to each other at their abutment area and are held at a predetermined distance in the flow direction by a spacer. The two filter bellows have the same dimensions in the direction transverse to the flow direction and are joined by a common circumferential seal made of PUR material that connects to the sides of both filter bellows at their abutment area. A drawback of this is that the connection between the two filter bellows does not have sufficient load-bearing capacity, which creates problems, especially with respect to vibrations that occur during operation.
[0008] It would therefore be desirable to provide a filter element that integrates multiple filter stages while providing greater mechanical load capacity than known multi-stage filters. Summary of the Invention
[0009] Against this background, the present invention aims to provide an improved filter element.
[0010] This object is solved by a filter element having the features of claim 1 and by a filter device having the features of claim 17. Further embodiments of the invention are the subject of the dependent claims as well as the embodiments of the invention described below.
[0011] The filter element according to the present invention is particularly suitable for an air filter system, particularly a cabin air filter system or a fuel cell intake air filter system. The filter element comprises two filter bellows arranged adjacent to each other in a predetermined flow direction so as to be able to flow serially through the filter bellows. Each filter bellows has an inlet face, an outlet face, and at least four side faces. The filter bellows are adjacent to each other at an interface region between the outlet face of the first filter bellows and the inlet face of the second filter bellows. A circumferential seal is present in the interface region, directly connecting the two filter bellows to each other by a material bond. In at least one direction transverse to the flow direction, one of the filter bellows has a shorter length than the other filter bellows, and the filter bellows are arranged relative to each other in at least one direction transverse to the flow direction such that, in the interface region, there is a free space not covered by the smaller filter bellow along at least one edge of the larger filter bellows on the inlet or outlet face of the larger filter bellows. In the region of the free space, the circumferential seal is directly connected to the inlet or outlet face of the larger filter bellows by a material bond.
[0012] The filter element according to the invention therefore significantly improves the mechanical load-bearing capacity of the connection between the two filter bellows. This is achieved in particular by the enlarged contact surface of the circumferential seal, which is integrally formed on the filter bellows by material bonding. Furthermore, by forming the circumferential seal integrally on the inlet or outlet face of the larger filter bellows, the rigidity of the entire filter element is further increased, which improves handling, especially during maintenance.
[0013] The term "free space" refers to an imaginary area that exists at the inlet or outlet face of the larger filter element in the interface region due to the smaller dimensions of one filter element compared to the other. However, in the completed filter element, this imaginary free space is not left open because a circumferential seal is installed in this imaginary free space, but is understood as a secondary means of describing the structural configuration of the filter element.
[0014] Advantageously, the filter element according to the invention is made exclusively of thermally recyclable materials, so that disposal problems do not arise and in particular the recycling process does not require dismantling of the individual components of the filter element.
[0015] In some embodiments, the filter bellows and / or the filter element itself are each configured in a cubic shape, which allows for inexpensive assembly of the filter element and efficient use of installation space.
[0016] Furthermore, especially in the case of a cubic geometry, symmetry is established with respect to a given plane passing through the filter element, which allows for a favorable mass distribution of the filter element.
[0017] Here, with respect to the axial and radial directions of a filter element, "axial" refers to the flow direction, which is perpendicular to the inlet face or side of, for example, a cubic-shaped filter element, and the term "radial" refers in particular to the direction normal to the side or wall of the frame or to the side of, in particular, a cubic-shaped filter element.
[0018] Each filter bellows may contain a filter material, such as a filter fabric, filter cloth, or filter nonwoven. In particular, the filter material may be manufactured by a spunbonding or meltblown process. Furthermore, the filter material may be felted or needled. The filter material may contain natural fibers such as cotton, or synthetic fibers such as polyester, polyphenylsulfide, or polytetrafluoroethylene.
[0019] To form each filter bellows, the filter media is folded or corrugated multiple times. The pleats of the filter bellows may be spaced, for example, between 3 and 5 mm apart, and the pleats may be 20 to 30 mm high. In some embodiments, there may be between 30 and 300 pleats.
[0020] In this respect, the filter element according to the invention is suitable as a replaceable part of an air filter system, in particular a cabin air filter system or an intake air filter system for a fuel cell, and can in particular be mounted in a filter housing fixed to the vehicle.
[0021] In some embodiments, at least one edge of the larger filter bellows, the circumferential seal is further directly connected to at least one side of each of the two filter bellows by a material bond, which further improves the load-bearing capacity of the connection between the two filter elements and increases the stiffness of the entire filter element, in particular against axial loads and / or bending about an axis transverse to the flow direction.
[0022] In some embodiments, the circumferential seal comprises or consists of a plastic material, in particular a foamed polyurethane or a thermoplastic elastomer. The material can be conveniently provided in a liquid or pasty initial state and can be integrally formed by direct material bonding to both filter bellows using a mould according to the method according to the invention. In the mould, the starting material provided in a liquid or pasty initial state hardens and then forms the final material of the circumferential seal.
[0023] According to a further embodiment, the circumferential seal has, in cross section, at least three legs, namely: a lateral leg connected to the inlet or outlet face of the larger filter bellows; a first longitudinal leg connected to a side of the smaller filter bellows; and a second longitudinal leg connected to the side of the larger filter bellows.
[0024] Advantageously, all three legs of the circumferential seal can be manufactured in one tool (mold) and in a common process, in other words, the above-mentioned legs, i.e. the transverse leg, the first longitudinal leg and the second longitudinal leg, can be called connecting legs of the circumferential seal, since they mainly serve as the connection for both filter bellows.
[0025] The circumferential seal also includes a radially protruding circumferential seal area configured for sealing contact with the housing seal surface of the filter housing. This seal area can have various cross sections as deemed appropriate by those skilled in the art to meet the technical constraints of the filter housing. For example, the seal area can be configured for radial or axial sealing and can alternatively or additionally have one or more seal lips or seal grooves. Advantageously, the seal area can be manufactured in a common casting process together with the connecting legs of the circumferential seal.
[0026] In some embodiments, the filter bellows each have exactly four sides, in particular when cubic in shape, but the filter bellows may also have other basic shapes, in particular polygonal, in particular polygonal with five or more sides.
[0027] According to a further embodiment, the smaller filter bellows has a shorter length than the other filter bellows in at least one further direction transverse to the flow direction, and the filter bellows are arranged relative to one another in at least one further direction transverse to the flow direction in such a way that, in the interface region, along at least one further edge of the larger filter bellows, there is a free space on the inlet or outlet face of the larger filter bellows that is not covered by the smaller filter bellows, and in the region of the free space the circumferential seal is directly connected to the inlet or outlet face of the larger filter bellows by a material bond.
[0028] In some embodiments, a free space may exist at at least one pair of oppositely disposed edges on the inlet or outlet face of the larger filter bellows. In other words, the smaller filter bellows may be offset by a predetermined amount from the pair of oppositely disposed edges of the larger filter bellows in two different directions extending transversely to the flow direction. In this case, the connection between the circumferential seal and the inlet or outlet face of the larger filter bellows may be formed over the entire circumferential direction in the region of the free space.
[0029] Furthermore, at least one of the filter bellows may contain at least one particle filter material, particularly a synthetic nonwoven material and / or a cellulose-based filter material, in particular meeting filtration class H13 or H14 according to DIN EN 1822-1. Alternatively or additionally, at least one of the filter bellows may contain at least one gas filter material, particularly containing at least one adsorbent, in particular activated carbon, zeolite, and / or an ion exchanger. The gas filter material may also contain its own particle filter layer, particularly a synthetic nonwoven material. Alternatively, the gas filter material may consist solely of a support layer on which the adsorbent, provided in granular or particulate form, is immobilized, and the support layer may comprise a nonwoven material with a significantly larger pore size than the particle filter material.
[0030] According to a further preferred embodiment, the smaller filter bellows contains a gas filter material. This has the advantage that a larger filter area can be ensured in the filter bellows with particle filter material. This is particularly advantageous when using high-efficiency particle filter materials in the HEPA range. On the other hand, the circumferential seal completely encloses the edge of the smaller filter bellows facing the larger filter bellows, effectively preventing the sorbent, in particular activated carbon particles, from escaping to the outside. If sorbent particles detach from the gas filter material during operation, they will not leak into the environment but will essentially be trapped in the interface area.
[0031] In particular, the filter bellows containing the particle filter material can be arranged upstream of the filter bellows containing the gas filter material, so that the air flow passing through the filter element according to the invention first flows through the filter bellows containing the particle filter material and then through the filter bellows containing the gas filter material. This is advantageous in that the air from which particles have been removed can flow through the gas filter material, and the adsorbent of the gas filter material is not "clogged" by particles, thereby improving the adsorption performance of the gas filter material, especially over time.
[0032] Independently of the foregoing, the smaller filter bellows may be located upstream and the larger filter bellows downstream.
[0033] Furthermore, the particle filter material and / or gas filter material may have antibacterial and / or antiallergic properties. Examples of antibacterial substances include zinc pyrithione and nanosilver, and examples of antiallergic substances include polyphenols. Examples of antibacterial substances include zinc pyrithione and nanoparticles of silver, and examples of antiallergic substances include polyphenols.
[0034] According to yet another embodiment, the smaller filter bellows includes an at least partially circumferentially extending frame element, in particular including at least one side band provided at the pleated end face edge of the filter bellows and / or at least one head band provided at the end pleat of the filter bellows. The side band and / or the head band may comprise or consist of a synthetic nonwoven material. The side band is in particular sealingly bonded to the pleated profile, and the head band forms a sealed closure with respect to the folded filter medium.
[0035] According to yet another embodiment, the circumferential seal is directly connected by a material bond to a frame element that extends at least partially in the circumferential direction of the smaller filter bellows. This further improves the mechanical load-bearing capacity of the connection between the two filter bellows, which has a beneficial effect on the stiffness of the entire filter bellows. Furthermore, in embodiments in which the smaller filter bellows contains a gas filter material, the frame element "encloses" the smaller filter bellows, thereby preventing the escape of sorbent particles present in the gas filter material.
[0036] Independently of the above-mentioned embodiments, the direct material bond connection of the circumferential seal may also be a foam connection, which is an industrially established process, especially when polyurethane is used as raw material.
[0037] Alternatively or additionally, the larger filter bellows may have sealed pleat end edges, in particular in the form of fluid-tight adhesive connections between the pleat gaps and / or at least one frame element at the pleat end edges, which prevents bypass of the filter medium of the larger filter bellows.
[0038] Furthermore, spacer elements may be present in the interface region, determining the distance between the two filter bellows in the flow direction relative to each other. The spacer elements extend with at least one component crossing the direction of extension of the pleat length of at least one of the filter bellows, in particular, to enable optimal support at as many contact points as possible. In principle, providing a distance between the two filter bellows is advantageous for equalizing the flow through both filter bellows. It should be noted that the spacer elements not only support the two filter elements relative to each other, but also serve to stabilize the entire filter element.
[0039] The spacer element may include an adhesive strip provided at the tip of at least one of the pleats of the filter bellows, at least one thread bonded to the pleat tip, and / or a lattice arranged in the interface region. The lattice may be made of a plastic material, particularly an injection-molded part, which provides particularly good reinforcement for the spacer element.
[0040] In some embodiments, the lattice includes an at least partially circumferentially extending collar that projects radially beyond the larger filter bellows. Preferably, the lattice collar extends in the entire circumferential direction. The lattice collar can in particular be embedded in the material of the circumferential seal, preferably foamed into the material of the circumferential seal. In particular, the lattice collar is completely surrounded by the material of the circumferential seal.
[0041] The collar of the lattice may extend at least partially in the plane in which the interface region lies, in particular. In some embodiments, the collar of the lattice can be configured at least partially at an angle to the plane of the interface region, in particular to internally reinforce the sealing region of the circumferential seal. In some embodiments, the collar of the lattice can be configured at an angle in a direction towards the larger filter bellows.
[0042] The collar portion is in particular formed integrally with the material of the grille portion and can be manufactured together with the grille portion in a common process.
[0043] At least a portion of the grid may also extend radially beyond the collar and form a protruding rim that extends at least partially circumferentially beyond the circumferential seal. Preferably, the protruding rim extends over the entire circumferential direction. The protruding rim may in particular be integrally formed with the grid and / or collar material and manufactured together with the grid and / or collar in a common process.
[0044] The collar and / or the protruding rim are preferably made of a harder material than the circumferential seal, in particular a plastic material, in particular an injection-moldable plastic material.
[0045] The protruding rim, on the one hand, further reinforces the filter element, and on the other hand, can form at least one fastening device thereon, which can hold the filter element in the filter housing. The fastening device can, for example, be a tab with at least one fastening element, for example, a through opening for screwing or a snap element.
[0046] The filter bellows may have different pleat spacing, in particular the pleat spacing of the smaller filter bellows may be greater than the pleat spacing of the larger filter bellows, i.e. the pleat spacing of the filter bellows containing gas filter material may be greater than the pleat spacing of the filter bellows containing particle filter material.
[0047] A further aspect of the invention relates to a filter device, in particular a cabin air filter system or a fuel cell intake air filter system, comprising a filter housing having two housing parts, at least one of which includes a filter element receiving section in which a filter element according to the invention is arranged, the filter housing having at least one circumferentially extending housing sealing surface against which a circumferential seal of the filter element sealingly abuts.
[0048] In some embodiments, when the filter element is placed as intended within the filter housing, the circumferential seal is axially compressed between the two housing portions.
[0049] Further embodiments of the present invention include not only explicitly mentioned combinations of features disclosed above or below with respect to the exemplary embodiments. Also, a person skilled in the art could add individual aspects as improvements or supplements to each basic form of the present invention. Hereinafter, the present invention will be described in more detail with the aid of embodiments, with reference to the accompanying drawings. [Brief explanation of the drawings]
[0050] [Figure 1] 1 is an isometric view of a filter element according to the present invention. [Figure 2] 1 is a plan view of a filter element according to the present invention; [Figure 3] 3 is a cross-sectional view taken along the line AA in FIG. 2. [Figure 4] 1 is a side view with a cross-sectional portion of a filter element according to the present invention. [Figure 5] FIG. 5 is a diagram showing a detailed portion Z of FIG. [Figure 6] 1 is a longitudinal section of a filter device according to the present invention; [Figure 7] 10 is a cross-sectional view of a filter element of the present invention according to a further embodiment. [Figure 8] 10 is a cross-sectional view of a filter element of the present invention according to a further embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0051] FIG. 1 is an isometric view of a filter element 10 according to the present invention. The filter element 10 includes two filter bellows 1, 2, each having a filter material arranged in pleats 15, 25. The filter bellows 1, 2 are arranged adjacent to each other in a predetermined flow direction D so as to be able to flow in series. Each of the filter bellows 1, 2 has an inlet face 11, 21, an outlet face 12, 22 (see FIG. 3), and four side faces 13, 14, 23, 24. At the longitudinal ends of the pleats 15, 25, the folded filter material of the filter bellows 1, 2 has pleat end face edges 15′, 25′, respectively (see FIG. 4). The first filter bellows 1 is arranged upstream of the second filter bellows 2. The first filter bellows 1 contains a gas filter material, in particular activated carbon as an adsorbent, while the second filter bellows 2 is made of a particle filter material.
[0052] The folded filter medium of the first filter bellows 1 is provided at each of its pleat end face edges 15' (see FIG. 4) with a side band 131 and at each of its end pleats with a head band 141. The side bands 131 and the head band 141 form circumferentially extending frame elements that surround the folded filter medium 15 of the first filter bellows 1.
[0053] The basic shape of the entire filter element 10 and the filter bellows 1, 2 is cubic, with clearly defined long and short sides.
[0054] Furthermore, the filter element 10 comprises a circumferential seal 3 which connects the two filter bellows 1, 2 and which is formed integrally with them by direct material bonding, in particular by foam moulding.
[0055] The second filter bellows 2 has sealed pleat end edges 25' which are realized in the form of fluid-tight adhesive connections in the pleat gaps 251 (see FIG. 4). Alternatively, the pleat end edges 25' of the filter medium of the second filter bellows 2 can be provided with frame elements for sealing the pleat end edges.
[0056] The first filter bellows 1 is smaller than the second filter bellows 2 (here "smaller" refers to the dimension transverse to the flow direction D).
[0057] FIG. 2 shows a plan view of a filter element 10 according to the invention, with a first filter bellows 1 arranged on top.
[0058] FIG. 3 is a cross-sectional view taken along section AA, which extends parallel to the short sides 14, 24 of the filter element 10 shown in FIG. 2. In FIG. 3, the internal configuration of the filter element 10 can be seen, particularly the connection of the two filter bellows 1, 2 by the circumferential seal 3. The filter bellows 1, 2 are adjacent to each other at an interface region S between the outflow surface 12 of the first filter bellows 1 and the inflow surface 21 of the second filter bellows 2. The filter bellows 1, 2 are held at a predetermined distance from each other in the flow direction D by spacer elements 26. The spacer elements 26 extend in a direction transverse to the direction of extension of the pleats of at least one of the filter bellows 1, 2. The spacer elements 26 are, in particular, adhesive strips applied to the pleat tips 27 of the second filter bellows 2 or threads glued to the pleat tips 27.
[0059] Since the first filter bellows 1 is smaller than the second filter bellows 2, the oppositely disposed edges of the larger filter bellows 2 have free spaces F on the inlet face 21 in the interface area S that is not covered by the first filter bellows 1. The smaller first filter bellows 1 is offset so that there are free spaces F on the oppositely disposed edges of the larger second filter bellows 2. In particular, the free spaces F on the oppositely disposed edges of the larger second filter bellows 2 have the same dimensions.
[0060] In the region of the free space F, the circumferential seal 3 is connected by a material bond directly to the inlet face 21 of the larger filter bellows 2. Furthermore, the circumferential seal 3 is also connected by a material bond directly to the side faces 13, 14 of the smaller first filter bellows 1 (see FIG. 4) and to the side faces 23, 24 of the larger second filter bellows 2 (see FIG. 4).
[0061] The two filter bellows 1 , 2 are therefore connected to one another by a circumferential seal 3 .
[0062] The connection takes place via the respective side surfaces 13, 14, 23, 24 of the two filter bellows 1, 2 and via the inlet face 21 of the second filter bellows 2, thereby maximizing the contact surface of the circumferential seal 3 with the filter bellows 1, 2 and thereby achieving a mechanically very load-bearing connection. The connection via the respective side surfaces 13, 14, 23, 24 of the two filter bellows 1, 2 and via the inlet face 21 of the second filter bellows 2 preferably extends completely circumferentially.
[0063] The radially protruding area of the circumferential seal 3 has a sealing area 31 which comes into contact with at least one sealing surface provided on the housing when the filter element 10 is in the installed state.
[0064] FIG. 4 shows the filter element 10 in a side view, projected along the short sides 14, 24, and in particular the connection between the spacer elements 26 and the pleat tips 27 of the second filter bellows 2 can be seen.
[0065] For more details, see Detail Z in FIG.
[0066] The circumferential seal 3 has a first longitudinal leg 33 connected to the side surface 14 of the first filter bellows 1. More specifically, the first longitudinal leg 33 is connected to a head band 141 located at the end pleats of the folded filter medium of the first filter bellows 1, which is arranged at the side surface 14. The circumferential seal 3 further has a second longitudinal leg 34 connected to the side surface 24 of the second filter bellows 1. More specifically, the second longitudinal leg 34 is connected to the end pleats of the filter medium of the second filter bellows 2. The circumferential seal 3 further has a transverse leg 32 connected to the inlet face 21 of the second filter bellows 2. The transverse leg 32 is also advantageously connected to the abutment surface of the head band 141 of the first filter bellows 1. Similarly, the transverse leg 32 may advantageously be connected to the abutment surface of a side band 131 of the first filter bellows 1, as shown in FIG. 3 . The term "abutment surface" means an axially oriented cover surface. The connection of the circumferential seal 3 with the different contact surfaces of the two filter bellows 1, 2 as described above, and the T-shape formed by the longitudinal legs 33, 34 and the transverse legs 32, significantly increase the rigidity of the entire filter element 10 in the connection region of the two filter bellows 1, 2. In particular, the arrangement of the spacer elements 26 in the interface region S further strengthens the rigidity against bending about an axis transverse to the flow direction D.
[0067] 6 shows a filter element 10 of the present invention installed in a filter housing 4 of an air filter system 100, particularly a cabin air filter system or a fuel cell intake air filter system. The filter housing 4 includes two housing sections 41 and 42, which together define a filter element receiving section. The lower housing section 41 may be a housing pan, and the upper housing section 42 may be a housing cover.
[0068] The first housing part 41 and the second housing part 42 each provide a circumferential sealing surface 411, 421, against which a sealing area 31 of a circumferential seal 3 of the filter element 1 is sealingly arranged. In this regard, the sealing area 31 of the circumferential seal 3 is axially sealingly sandwiched between the housing parts 41, 42 via respective axial contact surfaces facing the sealing surface 411 of the first housing part 41 and the sealing surface 421 of the first housing part 42. In order to improve the transmission of forces to the sealing area 31 of the circumferential seal 3, at least one of the housing parts 41, 42 is provided with a circumferential rib that presses against the respective axial contact surface of the sealing area 31.
[0069] Figure 7 is a longitudinal cross-sectional view of a filter element 10 of the present invention according to a further embodiment. The filter element 10 substantially corresponds to the filter element 10 shown in Figures 1 to 5, so that the features, combinations of features and their particular technical advantages described in connection with this filter element 10 also apply to the filter device 100 of Figure 6. Only the differences will be described below.
[0070] The spacer element 26 comprises a lattice portion 26" situated in the interface region S between the two filter bellows 1, 2. The lattice portion 26' is fluid permeable and in particular has a plurality of lattice openings between which extend lattice webs that contact the pleat tips of each of the filter bellows 1, 2 facing the interface region S, separating the filter bellows 1, 2 by a predetermined distance. The lattice portion 26" has a circumferentially extending collar portion 261 that projects radially beyond the larger filter bellows 2. The collar portion 261 of the lattice portion 26" is embedded in the material of the circumferential seal 3, in particular is foam-molded into the material of the circumferential seal 3. The collar portion 261 of the lattice portion 26" is in particular completely surrounded, i.e. from all sides, by the material of the circumferential seal 3.
[0071] The collar portion 261 of the lattice portion 26" extends in a first portion in the plane in which the interface area S is located. In a second portion, the collar portion 261 is angled relative to the plane of the interface area S in order to reinforce the sealing area 31 of the circumferential seal 3 from the inside. According to this embodiment, the collar portion 261 of the lattice portion 26" is angled in the direction of the larger filter bellows 2. The angled second portion may include a bent portion, a curved portion or a folded portion.
[0072] The collar portion 261 is integrally formed with the material of the grill portion 26" and, in particular, is manufactured together with the grill portion 26" in a common process.
[0073] When manufacturing the filter element 10, first the grid portion 26" is prepared, together with the collar portion 261, and then the two filter bellows 1, 2 are placed thereon. In a subsequent step, the circumferential seal 3 is foamed or cast, thereby connecting the two filter bellows 1, 2 and also forming the sealing area 31, with the collar portion 261 being embedded in the material of the circumferential seal 3. The foaming or casting can be carried out using a foaming or casting mold having a negative mold of the circumferential seal 3.
[0074] Furthermore, at least a part of the grid portion 26" may extend beyond the collar portion 261 in a radial view, as shown in the longitudinal section of the embodiment according to Figure 8, and may form a protruding rim 262 that extends circumferentially at least partially beyond the circumferential seal 3. The protruding rim 262 is not surrounded by the material of the circumferential seal 3 and is in particular exposed. In particular, the protruding rim 262 extends completely circumferentially along the circumferential seal 3. The protruding rim 262 is integrally formed with the material of the grid portion 26" and / or the material of the collar portion 261 and can be manufactured in a common process together with the grid portion 26" and / or the collar portion 261. The protruding rim 262 is in particular configured as a collar and is angled relative to the plane of the interface area S. The protruding rim 262 is in particular angled in a direction opposite to the angled second portion of the collar portion 261.
[0075] On the one hand, the protruding rim 262 reinforces the filter element 10, and on the other hand, the protruding rim 262 can have integrally formed therewith a fastening device that can hold the filter element 10 in the filter housing. The fastening device can be, for example, a tab with at least one fastening element, for example, a through opening or a snap element for screwing, although this is not shown in the drawings. [Explanation of symbols]
[0076] 100 Filter device 10 Filter Elements 1 First filter bellows 11 inlet surface of first filter bellows 12 Outlet surface of first filter bellows 13, 14 Side of first filter bellows 131 Side band of first filter bellows 141 First filter bellows head band 15 First filter bellows pleats 15' First filter bellows pleated end edge 2 Second filter bellows 21 inlet surface of second filter bellows 22 Outlet surface of second filter bellows 23, 24 Side of second filter bellows 25 Second filter bellows pleats 25' Pleated end edge of second filter bellows 251 Second filter bellows pleat gap 26 Spacer Elements 26' adhesive strip 26” lattice section 261 Color part of the grid 262 Protruding rim of collar of lattice 27 Pleated tip of second filter bellows 3 Circumferential seal 31 Sealing Area 32 Lateral legs 33 First vertical leg 34 Second vertical leg D Flow direction F free space S interface area 4 Filter Housing 41 First housing part 411 circumferential seal surface of first housing part 42 Second housing part 421 Circumferential sealing surface of second housing section
Claims
1. A filter element (10) for an air filter system, in particular a cabin air filter system or an intake air filter system for a fuel cell, in particular an air filter element, comprising: Two filter bellows (1, 2) are arranged adjacent to each other so as to be able to flow in series in a predetermined flow direction (D), Each of the filter bellows (1, 2) has an inlet face (11, 21), an outlet face (12, 22), and at least four side faces (13, 14, 23, 24), said filter bellows (1, 2) adjoin each other at an interface area (S) between the outflow surface (12) of the first filter bellows (1) and the inflow surface (21) of the second filter bellows (2); the filter element further comprises a circumferential seal (3) present in the interface area (S) that directly connects the two filter bellows (1, 2) to each other by a material bond, a filter element (10) in which one of the filter bellows (1, 2) has a length that is smaller than the other of the filter bellows (1, 2) in at least one direction that intersects the flow direction (D), and the filter bellows (1, 2) are arranged relative to one another in the at least one direction that intersects the flow direction (D) in such a way that, in the interface region (S), along at least one edge of the larger filter bellows (1, 2), there is a free space (F) that is not covered by the smaller filter bellows (1, 2) on the inlet flow surface (11, 21) or the outlet flow surface (12, 22) of the larger filter bellows (1, 2), and in the region of the free space (F), the circumferential seal (3) is directly connected to the inlet flow surface (11, 21) or the outlet flow surface (12, 22) of the larger filter bellows (1, 2) by a material bond.
2. 2. The filter element (10) according to claim 1, wherein at the at least one edge of the larger filter bellows (1, 2), the circumferential seal (3) is further directly connected to at least one side surface (13, 14, 23, 24) of each of the two filter bellows (1, 2) by a material bond.
3. 3. The filter element (10) according to claim 1 or 2, wherein the circumferential seal (3) comprises or consists of a plastic material, in particular a foamed polyurethane or a thermoplastic elastomer.
4. The circumferential seal (3) is a transverse leg (32) connected to the inlet face (11, 21) or outlet face (12, 22) of the larger filter bellows (1, 2); a first longitudinal leg (33) connected to the side (13, 14, 23, 24) of the smaller filter bellows (1, 2); and a second longitudinal leg (34) connected to a side (13, 14, 23, 24) of the larger filter bellows (1, 2).
5. The filter element (10) according to any one of claims 1 to 4, wherein the circumferential seal (3) comprises a radially protruding circumferential seal area (31) configured to sealingly contact a housing seal surface (411, 421) of the filter housing (4).
6. A filter element (10) according to any one of claims 1 to 5, wherein said filter bellows (1, 2) each have exactly four sides (13, 14, 23, 24) and / or have a basic cubic shape.
7. 7. The filter element (10) according to claim 1, wherein the smaller filter bellows (1, 2) has a shorter length than the other filter bellows (1, 2) in at least one further direction transverse to the flow direction (D), and the filter bellows (1, 2) are arranged relative to one another in the at least one further direction transverse to the flow direction (D) in such a way that, in the interface region (S), along at least one further edge of the larger filter bellows (1, 2), there is a free space (F) on the inlet face (11, 21) or the outlet face (12, 22) of the larger filter bellows (1, 2), which is not covered by the smaller filter bellows (1, 2), and in the region of the free space (F), the circumferential seal (3) is directly connected to the inlet face (11, 21) or the outlet face (12, 22) of the larger filter bellows (1, 2) by a material bond.
8. at least one of the filter bellows (1, 2) comprises at least one particle filter material, in particular comprising a synthetic nonwoven material and / or a cellulosic filter material, in particular the particle filter material fulfills filtration class H13 or H14 according to DIN EN 1822-1, and / or 8. The filter element (10) according to any one of claims 1 to 7, wherein at least one of the filter bellows (1, 2) comprises at least one gas filter material, in particular comprising at least one adsorbent, in particular activated carbon, zeolite and / or an ion exchanger.
9. 9. A filter element (10) according to claim 8, wherein the smaller filter bellows (1, 2) contain the gas filter material.
10. The smaller filter bellows (1, 2) comprises an at least partially circumferentially extending frame element (131, 141), in particular at least one side band (131) provided on the pleated end face edges (15', 25') of the filter bellows (1, 2) and / or at least one head band (141) provided on the end pleats of the filter bellows, in particular the side band and / or the head band (131, 141) comprising or consisting of a synthetic nonwoven material.
11. 11. The filter element (10) according to claim 10, wherein the circumferential seal (3) is directly connected to the at least partially circumferentially extending frame element (131, 141) of the smaller filter bellows (1, 2) by a material bond.
12. The filter element (10) according to any one of claims 1 to 11, wherein the direct material bond connection of the circumferential seal (3) is a foamed connection.
13. 13. The filter element (10) according to any one of claims 1 to 12, wherein the larger filter bellows (1, 2) has sealed pleat end edges (15', 25'), in particular fluid-tight adhesive connections in the pleat gaps (251) and / or at least one frame element provided on the pleat end edges (15', 25').
14. 14. The filter element (10) according to claim 1, wherein in the interface region (S) there are spacer elements (26, 26', 26") which predetermine the spacing of the two filter bellows (1, 2) relative to one another in the flow direction (D), the spacer elements (26, 26', 26") extending in particular with at least one component transverse to the direction of extension of the pleat length of at least one of the filter bellows (1, 2).
15. 15. The filter element (10) according to claim 14, wherein the spacer elements (26, 26', 26") comprise adhesive strips (26') provided at the tips of a plurality of pleats of at least one of the filter bellows (1, 2), at least one thread portion adhered to the pleat tips, and / or a lattice portion (26") arranged in the interface region (S).
16. 16. The filter element (10) according to any one of claims 1 to 15, wherein the filter bellows (1, 2) have different pleat spacings, in particular the pleat spacing of the smaller filter bellows (1, 2) is greater than the pleat spacing of the larger filter bellows (1, 2).
17. A filter device (100), in particular a filter device (100) for a cabin air filter system or an intake air filter system for a fuel cell, comprising:
17. A filter device (100) comprising a filter housing (4) having two housing parts (41, 42), at least one of which includes a filter element receiving portion in which a filter element is arranged, the filter housing (4) having at least one circumferential housing sealing surface (411, 421) against which a circumferential seal of the filter element sealingly abuts, the filter element being a filter element (10) according to any one of claims 1 to 16.
18. 18. The filter device (100) of claim 17, wherein when the filter element (10) is positioned in the filter housing (4) as intended, the circumferential seal (3) is axially compressed between the two housing parts (41, 42).