CABIN AIR FILTER MODULE

Description

Technical Area

[0001] The present invention relates to a filter element, in particular an interior air filter module for filtering air supplied to a driver's cabin in vehicles, agricultural machinery, construction machinery and work machines.

[0002] A filter module or filter element is generally understood to be a replaceable unit that can be arranged in a filter housing. It comprises at least one filter element made of a filter medium and usually also a structure that supports or holds the filter medium, and typically a seal. The respective filter medium usually has a limited service life. Therefore, filter modules must be replaced regularly as a unit.

[0003] Nowadays, the air flowing into a vehicle cabin is filtered as completely as possible to remove contaminants. Potential contaminants include fine dust, pollen, soot, harmful gases, and aerosols. Filtering such contaminants is particularly important in applications where high concentrations of pesticides or liquid fertilizers are present in the ambient air when spraying these substances. Various filter media are available for this purpose. For example, particle filters, activated carbon filters, and HEPA filters are commonly used. These are combined in different layers and arrangements to achieve the desired filtration efficiency for the cabin air. State of the art

[0004] From EP 3 520 878 A1, a filter module for filtering indoor air with three filter layers is known, wherein the filter layers are arranged in a common frame composed of extruded profile strips. One of the filter layers comprises an adsorption filter designed as a honeycomb structure, while the other two filter layers comprise particle filters. The particle filter layers comprise separate filter bellows through which air can flow in series, one of the filter bellows containing a HEPA filter medium. The profile strips of the frame hold the multiple filter layers inwards, while the filter module is sealed within a housing via the frame on the outside.

[0005] The filter module of EP 3 520 878 A1 comprises a circumferential sealing flange formed on the profile strips, which projects radially outwards in the area of ​​the two particle filter elements. Since the honeycomb structure is typically a rather heavy component of the device, the positioning of the sealing flange disclosed therein is technically disadvantageous in light of the effects of vibration. Projecting inwards, the profile strips also have two circumferential flange sections, against which two of the filter layers are supported. This design, in combination with the implementation of the particle filter layers as separate filter bellows, requires a comparatively large installation space in the axial direction.

[0006] The increasing integration of various components in machinery and the desire for longer filter lifespans lead to conflicting objectives in the design and construction of cabin air filters. For high integration, a very compact design and the smallest possible filter volume are advantageous. Longer service life, on the other hand, generally requires larger filter volumes. Furthermore, secure mounting of the filter modules and their stability must be guaranteed, even under vibrations and shocks during vehicle operation. In particular, resistance to vibrations is often not ensured in state-of-the-art filter modules.

[0007] From DE 10 2014 004 220 A1, an interior air filter element for an interior air filter for the driver's cab of agricultural and construction machinery, in particular with spraying or misting devices for plant protection products or fertilizers, is known, comprising a filter frame, a pre-filter layer, an adsorption filter layer, a fine filter layer, in particular for the separation of aerosols, wherein the filter layers are essentially flowed through along a flow direction.The disclosed cabin air filter element is characterized in that the filter element frame has a first area with a first effective cross-sectional area perpendicular to the flow direction and a second area with a second effective cross-sectional area perpendicular to the flow direction, as well as a circumferential seal for separating the raw side from the clean side in the installed state, wherein the first area is arranged upstream of the seal and the second area downstream of the seal, and the second effective cross-sectional area is only a part of the first effective cross-sectional area.

[0008] From US 2021 / 275955 A1, a vehicle cabin filter assembly is known that comprises a housing and several filter modules attached to the housing. The filter modules include a first filter module, a second filter module located downstream of the first filter module, and a third filter module located downstream of the second filter module. Each filter module includes a particulate filter element, and at least one of the filter modules includes a gas filter element. The second filter module has a higher filtration efficiency than the first filter module, and the third filter module has a higher filtration efficiency than the second filter module.

[0009] It is therefore desirable to create a filter module that requires less installation space and operates reliably even under vibration during vehicle operation. Disclosure of the invention

[0010] Against this background, the present invention aims to create an improved filter element or filter module.

[0011] Accordingly, a filter module, in particular an interior air filter module, is proposed which includes: a particle filter element, an adsorption filter element, and a frame surrounding the particle filter element and the adsorption filter element, which has a radially projecting sealing flange.

[0012] The particle filter element preferably has a pleated pack, which is formed from several layers of a zigzag-folded filter medium.

[0013] In particular, at least one layer has an aerosol-separating filter medium.

[0014] The adsorption filter element preferably comprises at least one shaped body capable of adsorbing at least hydrocarbons. The shaped body can also be designed to adsorb other pollutant gases, such as NH3 and / or H2S.

[0015] The sealing flange is preferably arranged such that it laterally encloses or surrounds the adsorption filter element on a circumferential outer wall thereof. A seal can be arranged on the sealing flange. The seal can, in particular, be injection-molded onto the sealing flange or applied to the sealing flange as a separate part. Alternatively or additionally, the seal can have a first section arranged on a first axial surface of the sealing flange and a second section arranged on a second axial surface of the sealing flange, the second axial surface of the sealing flange facing away from the first axial surface of the sealing flange. This allows for both an internal seal between the raw air area and the clean air area, as well as an external seal against the environment, to be achieved when the filter module is installed. In other words, the seal can be a bidirectional axial seal.

[0016] Such an arrangement of the sealing flange is advantageous in the operation of the filter module according to the invention, since the sealing flange is thereby located – with respect to the axial direction – as close as possible to the center of mass of the filter module. This improves the reliability of the filter module, since in particular there is a lower risk of the frame being damaged by forces occurring under vibration.

[0017] In particular, the particle filter element and the adsorption filter element in the filter module according to the invention are arranged such that they can be flowed through in series. Specifically, the particle filter element and the adsorption filter element are arranged such that the particle filter element is positioned upstream of the adsorption filter element, so that an airflow passing through the filter module according to the invention first flows through the particle filter element and then through the adsorption filter element. This has the advantage that the adsorption filter element can be supplied with particle-free air, which improves the adsorption performance of the adsorption filter element, especially over time, since the pores or channels of the adsorption filter element do not become clogged with particles.

[0018] The proposed filter module allows for a compact design, enabling its use in applications with limited installation space. Due to the frame design with the sealing flange provided particularly in the area of ​​the adsorption filter element, it ensures reliable installation and filter function even under vibration during operation.

[0019] The cabin air filter module is suitable as an interchangeable component for a cabin air filter for a driver's cab of agricultural and construction machinery, especially with spraying or misting devices for plant protection or fertilizers, and can be installed in a vehicle-mounted filter housing.

[0020] The layer of filter medium used in the particle filter element can be folded or corrugated. Common folds include zigzag and W-folds. The filter medium can be embossed and then sharply folded along the embossed edges to form fold lines. A sheet of filter material, which is then shaped accordingly, can serve as the starting material.

[0021] The filter medium can be, for example, a filter fabric, a filter mat, or a filter fleece. In particular, the filter medium can be manufactured using a spunbond or meltblown process. Furthermore, the filter medium can be felted or needle-punched. The filter medium can contain natural fibers, such as cotton, or synthetic fibers, for example, polyester, polyphenylene sulfide, or polytetrafluoroethylene. During processing, the fibers can be oriented in the direction of, diagonally to, and / or perpendicular to the machine direction.

[0022] It may also contain an adsorbent, such as activated carbon, within or between the layers. Furthermore, the filter medium may have antimicrobial and / or anti-allergenic properties. Examples of antimicrobial agents include zinc pyrithione or nanosilver, while polyphenols are suitable anti-allergenic agents.

[0023] A corresponding filter module is used to filter fluids, i.e., gaseous and / or liquid media, such as air. In this context, gaseous media or air also includes gas / air-solid mixtures and / or gas / air-liquid mixtures. For example, an air conditioning system may contain such a filter element.

[0024] An open filter medium, in particular, can be designed to remove particles of test dust A4 according to ISO 12103-1 from an airflow with a filtration velocity of 0.05 to 0.30 m / s, based on the filter medium area, at an air permeability greater than 3000 l / m²s (determined according to ISO 9237 at 200 Pa). The filtration characteristics can be determined, for example, according to DIN 14269-4.

[0025] A particularly high-efficiency filter medium can be designed to remove particles of test dust A2 according to ISO 12103-1 and NaCl aerosol particles according to DIN 71460-1 from an airflow with a filtration velocity of 0.05 to 0.30 m / s, based on the filter medium area, at an air permeability greater than 170 l / m²< s (determined according to ISO 9237 at 200 Pa). The filtration parameters can be determined, for example, according to DIN 14269-4.

[0026] In some embodiments, one of the multiple layers of the particle filter element comprises an aerosol-separating particle filter medium of filtration class H13 or H14 according to DIN EN 1822-1. In other words, at least one of the layers of the particle filter element can be a HEPA filter medium. The use of a nonwoven material made of plastic or glass fiber is conceivable. In some embodiments, an aerosol-filtering layer downstream is made of an ePTFE HEPA aerosol medium.

[0027] The particle filter element comprises a first layer on the upstream side and a second layer on the downstream side, the layers being folded together to form the pleated pack. In particular, the first and second layers are loosely folded or pleated together. "Affected" in this context refers not only to direct contact but also to indirect contact involving additional structures, such as adhesive layers or traces.

[0028] The first layer can largely retain dust particles on the upstream side, while the second, downstream layer can be designed as an aerosol medium. This reduces the clogging of the aerosol layer with particles.

[0029] The first layer, which can be referred to as a pre-filter layer, is, for example, a cellulose filter medium with epoxy impregnation. Preferably, the cellulose filter medium has a basis weight of 80–140 g / m², more preferably 100–120 g / m². In a preferred embodiment, the medium has a maximum pore size in the range of 30–40 µm and / or an air permeability of approximately 100–400 l / m² s, more preferably between 200 and 300 l / m² s, in each case measured at a pressure differential of 200 Pa (preferably measured here and subsequently according to DIN EN ISO 9237). In this way, the subsequent layers can be protected from dust accumulation, thus ensuring their proper function. In one version, the impregnation content, i.e., the weight percentage of the impregnating agent to the basis weight of the filter medium, is between 15 and 30%.

[0030] A combination of a spunbond nonwoven layer and a meltblown nonwoven layer (nonwoven made of meltblown plastic fibers) is preferably used as the nonwoven filter medium for the pre-filter layer. Both layers can be made of polyamide (PA), polyester (PES), or polypropylene (PP). The nonwoven filter medium preferably has a basis weight between 60 and 140 g / m², more preferably between 80 and 120 g / m², and / or a thickness in the range of 0.5–1 mm, particularly preferably between 0.5–0.8 mm. Furthermore, the air permeability is preferably in the range of 1000–2000 l / m² s, more preferably between 1200 and 1800 l / m² s at a pressure difference of 200 Pa.

[0031] In one embodiment, the pre-filter layer has a separation efficiency of 99% for test dust A2 or A4 according to ISO 12103-1, particularly according to ISO 5011.

[0032] In a preferred embodiment, the pre-filter layer has a surface mass of 75–125 g / m². Preferably, the filter medium of the pre-filter layer has an air permeability of 100–200 l / m² s at a pressure difference of 200 Pa.

[0033] The second layer, which can be referred to as the fine filter layer, can be designed as a HEPA bellows layer. In one embodiment, the fine filter layer consists of an initially unfolded filter medium containing glass fibers within a glass fiber layer. For example, a glass fiber fleece or glass fiber paper can be used. This preferably has a cover layer of spunbond nonwoven fabric laminated on one or both sides. This provides, in particular, mechanical protection for the often very sensitive glass fiber medium. This is especially advantageous when the glass fiber layer is folded, as it protects the medium from damage during folding, which could lead to local leaks or tears. Furthermore, such cover layers can improve the mechanical strength of the fine filter layer.

[0034] In one embodiment of the fine filter layer, the glass fibers have a fiber diameter in the range of 800 nm to 5 µm. Preferably, 90% of the fibers have a fiber diameter within this range. Preferably, fibers with diameters substantially across the entire fiber diameter range are present. Preferably, the mean fiber diameter lies within the aforementioned range. The fiber diameters can be measured, for example, according to the methods described in DE 10 2009 043 273 A1 or US 2011 / 0235867 A1. Preferably, the filter medium of the fine filter layer has a basis weight between 60 and 100 g / m², particularly preferably between 75 and 90 g / m². The glass fiber layer preferably has a thickness of 0.2–1 mm, particularly preferably 0.3–0.6 mm. A layer of glass fiber is particularly preferred which generates a resistance in the range of 300 - 600 Pa, preferably between 400 and 500 Pa, at an inflow velocity of 7.5 cm / s.The air permeability is preferably in the range of 25 to 45 l / m²s at a pressure drop of 200 Pa. At a flow velocity of 5.3 cm / s, the pressure drop is preferably in the range of 200 to 700 Pa, particularly preferably between 450 and 600 Pa, or alternatively between 270 and 480 Pa. The pore size is preferably in the range of 5 to 12 µm, particularly preferably between 8 and 10 µm.

[0035] Instead of glass fibers, synthetic fibers can also be used for the fine filter layer. In one embodiment, such a synthetic HEPA medium is used instead of the glass fiber media described. Polyester, polypropylene, or polyamide, for example, can be used as the material. The fiber layers are preferably formed in nonwoven form and produced, for example, by electrospinning, meltblowing, or other methods. An electret medium is preferred. Due to the material properties of synthetic filter media, cover and protective layers can be advantageously omitted. A layer of meltblown polyester nonwoven with a basis weight of, for example, 80–160 g / m², preferably between 80 and 120 g / m², and a thickness of, for example, approximately 0.4 to 1 mm is preferably used. This layer is further preferably applied to a carrier layer.Suitable substrates include, for example, a plastic support grid or a spunbond nonwoven layer. The other properties can correspond to those of the described fine filter layers with glass fibers.

[0036] The particle filter element has, in particular, an aerosol penetration of ≤ 0.05% measured according to EN 15695.

[0037] This integrated design of a pre-filter layer and a fine filter layer within the particle filter element offers an advantage over the prior art: the required installation space in the axial direction can be significantly reduced while substantially maintaining filtration performance. Compared to a design that uses separate filter bellows for the pre-filter and fine filter layers, the axial installation space saving is up to 50%.

[0038] In embodiments, the particle filter element comprises a frame enclosing the pleated pack, which includes side bands attached to pleated profiles of the pleated filter medium and head bands attached to end pleats of the pleated pack.

[0039] The side bands are sealed to the folding profiles, and the head bands also form a tight seal.

[0040] The pleat spacing of the pleat pack is, for example, between 3 and 5 mm, and the pleat height between 16 and 30 mm. In some embodiments, there can be between 100 and 150 pleats.

[0041] In embodiments, the frame is made of a plastic material, in particular a hard plastic material, wherein the partial filter elements (particle filter element and adsorption filter element) for the formation of the cabin air filter module lie in particular directly on top of each other and are sealed together by means of the frame.

[0042] In particular, the frame can be designed as an injection-molded plastic frame. This can either be prefabricated and hold the partial filter elements, which are glued or welded into the frame. Alternatively, the frame can be designed as an overmolded frame, formed by placing the partial filter elements in a mold and then overmolding them with an injection-molded frame, whereby the respective material bonds permanently with the partial filter elements during curing.

[0043] It is also conceivable that the frame is formed by a casting compound made of polyurethane (PUR) or another castable polymer, in particular a foamed polyurethane, i.e. polyurethane foam.

[0044] In some embodiments, the cabin air filter module further comprises a subframe that at least partially encloses the particulate filter element and the adsorption filter element laterally and fastens them together. This simplifies the manufacturing of the cabin air filter module by improving the handling of the semi-finished parts or components of the filter module. The subframe can be connected to the frame, in particular by bonding or foaming. Alternatively or additionally, the particulate filter element and the adsorption filter element can be bonded to the subframe.

[0045] The auxiliary frame can completely surround the particle filter element and the adsorption filter element. The auxiliary frame can, in particular, be made of or consist of a nonwoven material. The nonwoven material of the auxiliary frame can, in particular, have a greater thickness than the filter medium of the particle filter element. Alternatively or additionally, the nonwoven material of the auxiliary frame can have a higher flexural stiffness than the filter medium of the particle filter element.

[0046] In embodiments of the cabin air filter module, an intermediate filter layer is arranged downstream of the adsorption filter element. This intermediate filter layer is specifically designed as the final downstream filter stage of the filter module according to the invention. This prevents, for example, particulate adsorbent material from trickling out after adverse mechanical / abrasive forces. This is important to prevent adsorbent material from escaping from the honeycomb structure onto a clean side and thus from entering the interior during operation. Furthermore, the intermediate filter layer prevents adsorbent material from being "lost" from the adsorption filter element, ensuring that the adsorption capacity of the filter module is maintained throughout its planned service life.

[0047] In embodiments, the adsorption filter element comprises several shaped bodies which are connected to each other, in particular by means of a curable potting compound.

[0048] Suitable shaped bodies include honeycomb bodies, in particular those described in EP 2 946 827 A1, which is hereby fully incorporated by reference.

[0049] In embodiments, the at least one shaped body is at least partially made of a ceramic material, activated carbon material, ion exchange material, molecular sieve material, zeolite material, metal-organic framework material, and / or metal material.

[0050] Therefore, the materials for the molded body are particularly suitable as those named in paragraphs

[0006] to

[0012] of EP 2 946 827 A1. The shape and internal geometry of the molded body is designed, in particular as described for the honeycomb bodies of EP 2 946 827 A1 (see, for example, paragraphs

[0014] to

[0031] of EP 2 946 827 A1).

[0051] The use of a honeycomb structure as an adsorption filter element offers the advantage of significantly lower flow resistance compared to known adsorption filter element designs, such as folded, stacked, or wound layers of adsorbent-containing filter media (so-called combination filter media) or packed beds. Furthermore, a honeycomb structure allows for a very high adsorption capacity, enabling it to be used for a considerably longer period before gas breakthrough occurs.

[0052] The honeycomb structure is designed as an extruded body, structurally featuring channels and intervening walls. These channels permeate the honeycomb structure and are open on both sides, allowing the air to be filtered to flow between an inlet and outlet. The resulting pressure drop primarily stems from friction between the air and the channel walls – a blocking effect, as seen in "classic" filter media, does not occur.

[0053] Therefore, the use of a honeycomb structure is already surprising and cannot be compared to alternative adsorption filter concepts for the person skilled in the art, especially not to folded, stacked or wound layers of combination filter media.

[0054] The wall thickness of the honeycomb structure's channels can range from 200 micrometers to 400 micrometers. Such channel dimensions are advantageous for achieving a honeycomb structure with a high number of channels and thus a large contact area with the air to be filtered.

[0055] The number of channels in the honeycomb structure can range from 40 to 100 channels per square centimeter. This channel density has proven advantageous for achieving low pressure loss with high adsorption capacity.

[0056] The honeycomb core can be made of or contain activated carbon. The activated carbon, in the form of a paste or as part of a paste containing at least one suitable binder in addition to activated carbon particles, can be easily extruded into a honeycomb core. The proportion of activated carbon in the honeycomb core can, for example, range between 50 and 80 percent by weight. After extrusion, the pasty starting material is subjected to one or more drying steps and then sintered at high temperature. During this process, the binders contained in the paste are pyrolyzed, leaving behind a porous structure of activated carbon. The aforementioned paste composition has proven advantageous for both incorporating a sufficient amount of activated carbon into the honeycomb core and ensuring its mechanical stability.

[0057] The honeycomb structure can be impregnated in versions that improve the separation of non-hydrocarbon pollutants. In particular, the impregnation can improve the separation of NH3 and / or H2S.

[0058] In certain embodiments, the particle filter element, the adsorption filter element, the molded body, and / or the cabin air filter module itself are each cuboid in shape. Cuboid components can be easily assembled into the filter module and allow for efficient use of installation space.

[0059] Furthermore, particularly with cuboid-shaped external dimensions, mirror symmetries related to certain planes can result from the filter module, allowing for a favorable mass distribution of the filter module. It has proven advantageous to position the center of gravity of the filter module relative to its mounting or bracket on a filter housing in such a way that vibrations or movements of the vehicle result in only reduced mechanical stress.

[0060] In embodiments, the sealing flange defines a sealing plane, and the sealing flange is arranged such that the sealing plane extends through the interior of the molded body.

[0061] For example, the projecting sealing flange, as a projecting flat cantilever, surrounds the surrounding side parts of the frame to be held between corresponding sealing surfaces of a housing, optionally using one or more seals that follow a flange contour, and to separate a raw air area from a clean air area.

[0062] A sealing plane can be understood as a spatial plane in which the sealing flange or the additional seal lies during assembly. Such a (fictitious) plane divides the filter module into a first and a second part. Each of the two parts then encloses a mass fraction, and the sum of the two mass fractions adds up to the total mass of the filter module.

[0063] Therefore, in embodiments, the sealing flange can define a corresponding sealing plane that separates the cabin air filter module into a first and second half, wherein the sealing flange is arranged such that the ratio between the mass of the first half of the cabin air filter module and the mass of the second half of the cabin air filter module has a predetermined value. This value is, for example, between 0.5 and 1.5, preferably between 0.6 and 1.4, and particularly preferably between 0.8 and 1.2. Even more preferably, the value is between 0.9 and 1.1. In an embodiment with a value of 1.0, the center of mass of the cabin air filter module lies in the sealing plane.

[0064] The filter module is described as having an axial direction and a radial direction. "Axially" refers to the direction of flow, i.e., perpendicular to a flow surface or side of the filter module, which may be cuboid in shape. "Radial" refers specifically to the normal direction of a side surface or wall of the frame or a lateral surface of the filter element, which may be cuboid in shape.

[0065] In addition to the filter module, a filter arrangement with a filter housing for receiving at least one filter module as described above or below is proposed, wherein the filter housing comprises a first and second sealing section following the contour of the sealing flange and / or the seal.

[0066] In some embodiments, the sealing flange and / or the seal is axially pressed between two housing parts when the filter module is arranged in the filter housing as intended.

[0067] The filter assembly is preferably designed for filtration according to category 4 of DIN EN 15695-1. Therefore, the filter module is particularly suitable for use as an interior air filter in the driver's cab of agricultural and construction machinery, such as tractors, combine harvesters, or harvesting machines, especially those equipped with spraying or misting devices for plant protection products or fertilizers.

[0068] The norms and standards mentioned above and below are to be understood as they apply at the filing date of this application.

[0069] Other possible implementations of the invention also include combinations of features described previously or subsequently with regard to exemplary embodiments that are not explicitly mentioned. In such cases, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0070] Further embodiments of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will be explained in more detail below with reference to exemplary embodiments and the accompanying figures. Brief description of the drawings

[0071] It shows: Fig. 1 : a partial longitudinal sectional view of an embodiment of an interior air filter module; Fig. 2 : a cross-sectional view of the embodiment of an interior air filter module; Fig. 3 : a perspective exploded view of the cabin air filter module from Figs. 1 and 2 ; Fig. 4 : a perspective and cropped view of an embodiment of a filter arrangement with an interior air filter module made of Fig. 1 - 3 ; and Fig. 5 : a cross-sectional view of the filter arrangement from Fig. 4 .

[0072] In the figures, identical or functionally equivalent elements have been provided with the same reference symbols unless otherwise indicated. embodiment(s) of the invention

[0073] The following describes an embodiment of a filter module as an interior air filter module for the intake air of a driver's cab of a land vehicle and its use in a corresponding filter arrangement. The interior air filter module is in Figs. 1-3 presented in different views, and Figs. 4 and 5 The illustration shows the cabin air filter module in a filter housing as a filter assembly to form a category 4 cabin air filter according to the European standard DIN EN 15695. Besides dust, it is primarily aerosols and gaseous pollutants in the air that should not enter the driver's cabin to protect the driver.

[0074] The cabin air filter module 1 comprises, in the direction of flow L (see in the orientation of the Fig. 3(from top to bottom) a particle filter element 2, which corresponds to filter class H13 or H14 according to DIN EN 1822. It is therefore a HEPA filter (high-efficiency particulate air filter), which only allows gaseous airborne contaminants to pass through. The particle filter element 2 consists of a pleated pack formed from a zigzag-folded, two-layer, flat filter medium and a surrounding rim formed from two headbands 12A and two sidebands 12B. This results in a flat, cuboid geometry for the particle filter element 2.

[0075] The bellows pack or bellows is in Fig. 1Shown partially enlarged. A first layer 2A (pre-filter layer) and a second layer 2B (fine filter layer) of the filter medium 15 are initially laid loosely on top of each other during manufacturing and are then folded together in a zigzag pattern. To maintain the folded profiles, the side strips 12B are glued on. A head strip 12A is attached to each end fold, resulting in a manageable partial filter element 2. The pre-filter layer 2A is made of a synthetic plastic fleece, such as PET, PP, or PC. The fine filter layer 2B is made of an ePTFE material. The resulting air permeability of the media composite of layers 2A and 2B is approximately 87 l / m²s. Fig. 1 shows a partial longitudinal section along the in Fig. 3 recognizable longitudinal direction of the rod-shaped cuboid of the cabin air filter module 1 and Fig. 2 a cross-section perpendicular to the longitudinal direction LO.

[0076] Downstream of the particle filter element 2 is an adsorption filter element 3 formed from honeycomb structures 3A - 3E. The cuboid honeycomb structures 3A - 3E are tightly bonded to one another by a potting compound. During operation of the cabin air filter module 1, the pre-cleaned air flows through the material of the respective honeycomb structure 3A - 3E, which adsorbs at least hydrocarbons. For example, honeycomb structures 3A - 3E are used as described in EP 2 946 827 A1.

[0077] The particle filter element 2 and the adsorption filter element 3 are held together by means of a four-sided auxiliary frame 7. The underside of the particle filter element 2 and the top side of the adsorption filter element 3 are in contact, and the auxiliary frame 7, made of a nonwoven or side-band material, is laterally attached to both the side and head bands 12B, 12A as well as to the outer side surfaces (see markings 14 in Fig. 3) the honeycomb body 3A - 3E is attached, holds the two partial filter elements 2, 3 together.

[0078] A flat intermediate filter layer 8 made of a nonwoven material is attached to the underside of the adsorption filter element 3 to prevent, for example, absorption particles from trickling out of the adsorption filter element 3. The intermediate filter layer comprises, in particular, a nonwoven material, wherein the nonwoven material has a higher air permeability than the filter medium of the particle filter element. The intermediate filter layer 8 is, in particular, a planar layer and unfolded.

[0079] The auxiliary frame 7 and the intermediate filter layer 8 further increase the stability and thus the handling of the cabin air filter module 1. In addition, the filter module 1 is more resistant to accelerations such as vibrations, shaking, or shocks.

[0080] The cuboid unit, consisting of the partial filter elements 2, 3 connected to each other via the auxiliary frame 7 and closed off at the bottom by the intermediate filter layer 8, is laterally enclosed by a plastic frame 4 which has a radially projecting sealing rib or sealing flange 5. In the figures, an axial direction A is indicated by dashed lines and a radial direction R by dashed lines. When installed in a housing, the sealing rib 5 is axially clamped between two corresponding housing parts 9, 10 by means of a seal 6 (see Figure 1). Fig. 5 ).

[0081] At the in Figs. 4 and 5In the filter arrangement 100 shown, the filter housing is formed from an upper housing part 9 and a lower housing part 10. The lower housing part 10 has a U-shaped, laterally outwardly projecting receiving rib 11 for the seal 6 of the cabin air filter module 1. The upper housing part 9 has a corresponding profile rib 12, which presses the seal 6, arranged around the sealing flange 5, axially against the receiving rib 11, thus creating an airtight seal.

[0082] Within the filter assembly 100, there is a raw air zone RO and a clean air zone RE. The air to be filtered, potentially laden with dust and gases, enters the raw air zone RO through an inlet (not shown), is forced through the two partial filter elements 2 and 3 by a pressure difference, and collects as purified air for the vehicle cabin interior in the clean air zone RE. From the clean air zone RE, the clean air is supplied to the vehicle cabin through an outlet (not shown).

[0083] The sealing flange 5 and the seal 6, as well as the housing sections 11 and 12, have a rectangular shape. One can speak of a sealing plane DE, which, as shown in Fig. 4 The illustration shows that the interior of the housing 9, 10 and the inner volume of the cuboid adsorption filter element 3 are penetrated. The sealing plane DE corresponds to in Figs. 1 and 2 the indicated radial direction R.

[0084] To achieve a balanced mass ratio with respect to the mounting of the cabin air filter module 1 via the sealing flange 5 / the seal 6 on the housing parts 9, 10, the sealing plane DE in this embodiment passes through the center of mass of the cabin air filter module 1. More precisely, the sealing plane DE, defined by the positioning of the sealing flange 5, divides the total mass of the cabin air filter module 1 into an upper half OM and a lower half UM. The cabin air filter module 1 is particularly stable against accelerations in the housing 9, 10 when the mass of the first half OM of the cabin air filter module 1 and the mass of the second half UM of the cabin air filter module 1 are equal.

[0085] With unevenly distributed mass fractions of the cabin air filter module 1 with respect to the sealing plane DE, there is a higher risk of acceleration-induced stresses than in the proposed "equilibrium state". It can be said that the upper part or upper half OM of the cabin air filter module 1 is approximately the same weight as the lower part or lower half UM of the cabin air filter module 1, if the plane defined by the sealing flange is considered the dividing plane (sealing plane DE). Certain tolerances regarding the mass ratios can be allowed.

[0086] In the present embodiment, the sealing flange 5 surrounds the adsorption filter element 3 or is located opposite a respective side 14 of the molded body 3A-3E or of the auxiliary frame 7 at the level of the honeycomb bodies 3A-3E of the adsorption filter element 3. Depending on the axial mass distribution of the assembly of partial filter elements 2, 3, the sealing flange 5 can also be positioned at a different axial height of the filter element assembly.

[0087] Overall, a reliable filter module with efficiently used filter media is created, which is particularly robust against vibrations due to its lateral external mounting in a housing. Reference sign

[0088] 1 Cabin air filter module 2 Particle filter element 2A Pre-filter layer 2B HEPA layer 3 Adsorption filter element 3A - 3E Molded body 4 Frame 5 Sealing flange 6 Gasket 7 Auxiliary frame 8 Intermediate filter layer 9, 10 Housing part 11 Gasket receiving section 12A Top band 12B Side band 13 Sealing section 14 Circumferential wall of the adsorption filter element 15 Filter medium 100 filter arrangement Axial direction DE Sealing plane R Radial direction L Flow direction L O Longitudinal direction O Upper mass U Lower mass R Clean side R Raw side

Claims

1. Interior air filter module (1) with a particle filter element (2), an adsorption filter element (3), a frame (4) surrounding the particle filter element (2) and the adsorption filter element (3), which comprises a radially protruding sealing flange (5), wherein the particle filter element (2) comprises a pleated pack made of a plurality of layers of a zigzag-folded filter medium (15) and at least one layer (2B) features an aerosol-separating filter medium, wherein the particle filter element (2) comprises a first layer (2A) on the upstream side and a second layer (2B) on the downstream side, which are folded together to form the pleated pack, and wherein the adsorption filter element (3) features at least one molded part (3A-3E) formed as a honeycomb structure and adsorbing at least hydrocarbons, and wherein the sealing flange (5) is arranged such that it surrounds the adsorption filter element (3) laterally on a circumferential outer wall (14) thereof.

2. Interior air filter module according to claim 1, wherein the sealing flange (5) defines a sealing plane (DE), and the sealing flange (5) is arranged such that the sealing plane (DE) runs through the interior of the molded part (3A-3E) designed as a honeycomb structure.

3. Interior air filter module according to claim 1 or 2, wherein the sealing flange (5) defines a sealing plane (DE) which separates the interior air filter module (1) into a first and second half (OM, UM), wherein the sealing flange (5) is arranged such that a ratio between a mass of the first half (OM) of the interior air filter module (1) and a mass of the second half (UM) of the interior air filter module (1) is between 0.6 and 1.4, preferably between 0.8 and 1.2.

4. Interior air filter module according to one of the claims 1 to 3, further comprising a subframe (7) which at least partially encloses the particle filter element (2) and the adsorption filter element (3) laterally and connects them to each other, wherein the subframe (7) is connected to the frame (4), in particular glued to the frame (4).

5. Interior air filter module according to one of the claims 1 to 4, further comprising an intermediate filter layer (8) arranged on the downstream side of the adsorption filter element (3).

6. Interior air filter module according to one of the claims 1 to 5, wherein the particle filter element (2) comprises a frame enclosing the pleated pack, the frame comprising sidebands (12B) attached to folding profiles of the pleated filter medium (15) and headbands (12A) attached to end folds of the pleated pack.

7. Interior air filter module according to one of the claims 1 to 6, wherein one of the plurality of layers (2A, 2B) of the particle filter element (2) comprises an aerosol-separating particle filter medium (2A) of filtration class H13 or H14 according to DIN EN 1822-1.

8. Interior air filter module according to one of the claims 1 to 7, wherein the adsorption filter element (3) comprises a plurality of molded parts (3A-3E) connected to one another, in particular by means of a curable casting compound.

9. Interior air filter module according to one of the claims 1 to 8, wherein the at least one molded part (3A-3E) designed as a honeycomb structure is at least partially made of a ceramic material, activated carbon material, ion exchanger material, molecular sieve material, zeolite material, metalorganic framework material, and / or metal material.

10. Interior air filter module according to one of the claims 1 to 9, wherein the particle filter element (2), the adsorption filter element (3), the molded part (3A-3E) designed as a honeycomb structure, and / or the interior air filter module are each designed to be cuboid-shaped.

11. Interior air filter module according to one of the claims 1 to 10, further comprising a seal (6) attached to the sealing flange (5).

12. Interior air filter module according to one of the claims 1 to 11, wherein the particle filter element (2) and the adsorption filter element (3) are arranged in the filter module (1) according to the invention in such a way that they can be flowed through in series, wherein in particular the particle filter element (2) is arranged upstream of the adsorption filter element (3).