FILTER DEVICE, VEHICLE, USE AND METHOD

Abstract

A filter device has a filter element with filter medium body and surrounding frame with opposed lateral faces. A filter housing has opposed wall sections with two engagement counter elements for form fit engagement of an engagement element, respectively. The engagement counter elements are grooves in the wall sections with an insertion section and a blocking section connected to the insertion section and angled thereto. The insertion section permits insertion of the engagement element along a flow direction through the filter element. When mounted, the engagement element is arranged at one of the lateral frame faces, extends away from the filter medium body, and is held in the blocking section. Hold sections are connected to the engagement elements and, when mounted, at least partially engage the filter element. A vehicle with such a filter device and a method for mounting the filter element with engagement elements are provided.

Claims

1. A filter device comprising: a filter element comprising a filter medium body and a frame surrounding the filter medium body, wherein the frame comprises opposed lateral faces; engagement elements; a filter housing comprising two opposed wall sections, wherein the two opposed wall sections each comprise two engagement counter elements; wherein the engagement counter elements each are formed as a groove in the respective wall section and comprise an insertion section and a blocking section, wherein the blocking section is connected to the insertion section and angled in relation to the insertion section, wherein the blocking section is configured to receive with form fit a respective engagement element of the engagement elements, and wherein the insertion section is configured to permit an insertion movement of the respective engagement element substantially along a flow direction through the filter element in a mounted state of the filter element in the filter housing; wherein, in the mounted state of the filter element in the filter housing, the respective engagement element is arranged at one of the opposed lateral faces of the frame, extends away from the filter medium body, and is held in the respective blocking section of the respective engagement counter element; and hold sections connected to the engagement elements and, in the mounted state of the filter element in the filter housing, at least partially engaging the filter element.

2. The filter device according to claim 1, wherein the filter element comprises an inflow side and an outflow side, wherein the hold sections engage the filter element at the inflow side; at the outflow side; or at the inflow side and the outflow side.

3. The filter device according to claim 2, wherein the frame has an inflow side rim and an outflow side rim, wherein the hold sections engage the filter element at the inflow side rim of the frame; at the outflow side rim of the frame; or at the inflow side rim of the frame and the outflow side rim of the frame.

4. The filter device according to claim 1, wherein the two engagement counter elements extend oppositely in the respective wall section.

5. The filter device according to claim 4, wherein the two engagement counter elements each comprise an L shape, wherein a first leg of the L shape is the insertion section and a second leg of the L shape is the blocking section, and wherein the L shapes of the two engagement counter elements are arranged mirror-symmetrically to each other in the respective wall section.

6. The filter device according to claim 4, wherein the blocking sections of the two engagement counter elements face away from each other in the respective wall section and the insertion sections of the two engagement counter elements are arranged parallel to each other in the respective wall section.

7. The filter device according to claim 4, wherein, in an undeformed state of the filter element, a first distance between two of the engagement elements arranged at one of the opposed lateral faces of the frame is larger than a second distance between the insertion sections of the two engagement counter elements of the respective wall section so that, at an end of the insertion movement, said two engagement elements snap into the respective blocking sections.

8. The filter device according to claim 1, wherein the engagement elements are embodied as separate parts.

9. The filter device according to claim 8, wherein the engagement elements are detachably fastenable to the filter element and to the filter housing.

10. The filter device according to claim 1, wherein the engagement elements are fastened to the filter element.

11. The filter device according to claim 1, wherein the respective blocking section comprises a pocket or a through opening in the respective wall section, wherein the respective engagement element engages with form fit the pocket or the through opening in the mounted state of the filter element in the filter housing.

12. The filter device according to claim 1, wherein the opposed lateral faces of the frame each comprise two through openings, wherein the two through openings, in the mounted state of the filter element in the filter housing, are positioned opposite the blocking sections of the engagement counter elements in the opposed wall sections, respectively, wherein, in the mounted state of the filter element in the filter housing, the respective engagement element passes through the respective through opening and engages with form fit the respective blocking section.

13. The filter device according to claim 1, wherein the hold sections are arranged, in the mounted state of the filter element in the filter housing, in a recessed region of the filter medium body, respectively, wherein the recessed region of the filter medium body is accessible from a side from which mounting of the filter element in the filter housing is carried out.

14. The filter device according to claim 13, wherein the hold sections each comprise a cross shape and the engagement elements are arranged at a bottom end of the cross shape, respectively, wherein the cross shape laterally engages a rim of the frame, wherein the rim is arranged at an inflow side and/or at an outflow side of the filter element.

15. The filter device according to claim 14, wherein the cross shape engages the wall sections of the filter housing, respectively.

16. The filter device according to claim 13, wherein the hold sections each comprise a cross shape and the engagement elements are arranged at a bottom end of the cross shape, respectively, wherein the cross shape engages the wall sections of the filter housing, respectively.

17. The filter device according to claim 13, wherein an upper end of the cross shape comprises a grip section for manually mounting the engagement elements arranged thereat.

18. The filter device according to claim 13, wherein two of the hold sections are connected by a connection piece, respectively.

19. The filter device according to claim 18, wherein the connection piece extends parallel or perpendicularly to the opposed lateral faces of the frame in the mounted state of the filter element in the filter housing.

20. The filter device according to claim 1, wherein two of the engagement elements are connected by a connection piece, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0073] FIG. 1 shows a schematic illustration of a motor vehicle with a filter device.

[0074] FIG. 2 shows a perspective illustration of the filter device of FIG. 1 comprising a filter housing with an interior filter arranged therein.

[0075] FIG. 3 shows a perspective illustration of the interior filter of FIG. 2 comprising a frame and a filter medium.

[0076] FIG. 4 shows in a perspective illustration the filter medium of FIG. 3.

[0077] FIG. 5A shows in a perspective view a filter device according to a first embodiment.

[0078] FIG. 5B shows a section I-I of FIG. 5A.

[0079] FIG. 5C shows a section II-II of FIG. 5A.

[0080] FIG. 6 shows an exploded view of the filter device according to FIGS. 5A to 5C.

[0081] FIG. 7A shows in a perspective view a filter device according to a second embodiment.

[0082] FIG. 7B shows a section I-I of FIG. 7A.

[0083] FIG. 7C shows a section II-II of FIG. 7A.

[0084] FIG. 8 shows an exploded view of the filter device according to FIG. 7A to 7C.

[0085] FIG. 9A shows in a perspective view a filter device according to a third embodiment.

[0086] FIG. 9B shows a section I-I of FIG. 9A.

[0087] FIG. 9C shows a section II-II of FIG. 9A.

[0088] FIG. 10 shows in an exploded view the filter device according to FIGS. 9A to 9C.

[0089] FIG. 11, FIG. 12, FIG. 13, FIG. 14, and FIG. 15 show various embodiments of filter elements together with the correlated engagement elements.

[0090] FIG. 16 shows a method according to an embodiment.

[0091] In the Figures, same or functionally the same elements, if nothing to the contrary is mentioned, are provided with the same reference characters.

DETAILED DESCRIPTION

[0092] FIG. 1 shows a motor vehicle 1 with an air conditioning device 2 which is designed as a heating and air conditioning device. The air conditioning device 2 takes in ambient air 3 and supplies filtered air 4 to a cabin 5 of the motor vehicle 1. For this purpose, the air conditioning device 2 comprises a filter device 6 illustrated in FIG. 2.

[0093] The filter device 6 comprises a filter housing 7 with an interior filter 8 (presently also filter element) exchangeably arranged therein. The interior filter 8 is illustrated in more detail in FIG. 3. The interior filter 8 comprises a filter medium 9 (presently also filter medium body) which is connected in particular all around to a frame 10 (FIG. 3). The frame 10 can comprise, for example, lateral strips 11, 12 and head strips 13, 14.

[0094] The filter medium 9 is illustrated in FIG. 4 in isolation. For example, the filter medium 9 is a filter nonwoven, filter fabric, laid filter material or filter felt, in particular a needled felt. In particular, the filter medium 9 can be produced in a melt blowing method. The filter medium 9 can comprise natural fibers, such as cotton, or plastic fibers, for example, of polyester, polyphenyl sulfide or polytetrafluoroethylene. During processing, the fibers can be oriented in, at a slant to, and/or transverse to the machine direction M. Also, the fibers can be stretched in a spatial direction. The filter medium 9 can be a single layer or comprise multiple layers.

[0095] The filter medium 9 can have folds 15 which extend typically transversely to the machine direction M. The folded filter medium 9 is also referred to as pleating. The folds 15 can be produced by means of folding along sharp fold edges 16 (also referred to as fold tips) or as a corrugated embodiment of the filter medium 9. A respective fold 15 can be defined by two fold sections 15a which are connected to each other by a corresponding fold edge 16. According to the embodiment, the fold edges 16 face in or opposite to the inflow direction or flow direction, which is indicated in FIG. 2 by the arrow L. Folding can be embodied in particular as a zigzag folding.

[0096] Folding in which the folds 15 have a variable height H is possible also. Furthermore, the fold distance between the folds 15 can vary so that the distance A1 is different from the distance A2. The filter medium 9 can be designed to be self-supporting, i.e., the folds are shape-stable for an intended flow therethrough in the filtering operation.

[0097] The filter medium 9 is limited in machine direction M by end folds 17, 18. Transverse thereto, the filter medium 9 is delimited by fold end face edges 19, 20 (also referred to as fold profiles). Fold end face edge means the end face fold surface which extends between neighboring fold edges 16 of a respective fold 15.

[0098] The filter medium 9 can have a rectangular shape in the plan view, i.e., in the plane E of its areal extension. However, also a triangular, pentagonal or polygonal, round or oval shape are conceivable.

[0099] The lateral strips 11, 12 illustrated in FIG. 3 are connected to the fold end face edges 19, 20, the head strips 13, 14 to the end folds 17, 18, in particular by melting, welding or gluing. The lateral strips 11, 12 as well as the head strips 13, 14 can form the frame 10 as one piece or as multiple pieces. The lateral strips 11, 12 as well as the head strips 13, 14 can be manufactured, for example, of an in particular flexible fiber material or as, in particular stiff, injection molded plastic parts. In particular, the frame 10 can be produced by molding onto the filter medium 9.

[0100] The filter medium 9 can function as particle filter and filter out particles, in particular dust, suspended solids, or liquid droplets from the intake air 3. In addition, the filter medium 9 can function as an odor filter. For this purpose, it can comprise, for example, a layer of active carbon. The filter medium 9 in general can be designed to absorb or adsorb certain solid, liquid and/or gaseous substances.

[0101] In filtering operation, the filter medium 9, as illustrated in FIG. 2, is flowed through perpendicularly to its areal extension by air (flow direction L). The air (flow direction L) flows in this context from a raw side RO of the interior filter 8 to a clean side RE thereof.

[0102] In order to ensure a satisfactory sealing action between the raw and clean side RO, RE, a seal can be provided between the interior filter 8 and the filter housing 7. The seal can be integrated into the frame 10, for example. In this case, the frame 10 is formed at least partially of a sealing material. Alternatively, the seal can be provided as an additional part, for example, attached to the frame 10, in particular molded thereto. Such a seal 21 is illustrated in an exemplary fashion and partially in FIG. 3.

[0103] FIG. 5A shows in a perspective view a filter device 6 according to a first embodiment. FIG. 5B shows a section I-I, FIG. 5C a section II-II of FIG. 5A. FIG. 6 shows an exploded view of the first embodiment. In the following, reference is being had jointly to FIGS. 5A to 6.

[0104] The filter device 6 comprises a filter housing 7 (FIG. 5A) with filter element 8 received therein. The filter element 8 is held in the illustrated mounted position by means of a plurality of engagement elements 22a to 22d (FIG. 6).

[0105] A filter medium or filter medium body is identified in the Figures by 9. It is surrounded by a surrounding frame 10. The latter is comprised of lateral strips 11, 12 (presently also lateral faces) and head strips 13, 14.

[0106] The filter housing 7 comprises, for example, also a frame 23 which is comprised, for example, of opposed wall sections 24, 25 (FIG. 6) as well as 26, 27, respectively. In this context, the wall sections 24, 25 are positioned opposite the lateral strips 11, 12, the wall sections 26, 27 opposite the head strips 13, 14. The filter housing 7 could also have a different shape.

[0107] According to the embodiment, the wall sections 24, 25 are embodied each with two engagement counter elements 28a to 28d (FIG. 6). In them, one of the engagement elements 22a to 22d can be received with form fit, respectively. The engagement counter elements 28a to 28d each are embodied as a groove, for example. The engagement counter elements 28a, 28b are formed in this context in the wall section 24, the engagement counter elements 28c, 28d in the wall section 25.

[0108] The filter housing 7 together with the engagement counter elements 28a to 28d can be manufactured, for example, of plastic material, in particular in an injection molding process.

[0109] The engagement elements 22a to 22d are embodied as studs, for example. In particular, they can be provided, as illustrated in FIGS. 5A to 6, at an end of a hold section 29a to 29d or can be formed as one piece therewith. The hold sections 29a to 29d can be manufactured in the form of tabs. These tabs can provide a grip section for gripping the engagement elements 22a to 22d during assembly of the filter device 6 and can be easily gripped by hand. In the mounted state, the hold sections 29a to 29d can be arranged, for example, at least partially (or completely) in recessed regions 30. As can be seen in FIG. 5C, such recessed regions 30 can be formed in that a fold 15 of the filter medium body 9 is configured with a reduced height H= compared to the folds 15 adjoining the fold 15 at both sides and each provided with a height H.

[0110] The counter engagement elements 28a to 28d can be designed in detail as follows. As explained in the following in an exemplary fashion for the engagement counter element 28a (FIG. 6), each of the engagement counter elements 28a to 28d comprises an insertion section 31 and a blocking section 32. The sections 31, 32 are preferably part of the same continuous groove. The insertion section 31 extends preferably in the flow direction L (see FIG. 5C). It extends from an inflow-side rim 33 of the wall section 24, for example, toward a center thereof. Here, the insertion section 31 adjoins the blocking section 32 at an angle of, for example, 90?. In this way, an L shape results. At the end of the blocking section 32, a through hole 34 can be provided. The latter penetrates the material of the wall section 24 completely. Instead, only a pocket can be provided also which is configured so as to be inwardly open (accessible). The inflow side corresponds to the raw side RO of FIG. 2.

[0111] As can be seen in FIG. 6, the engagement counter elements 28a, 28b are designed to extend oppositely. For example, the blocking sections 32 extend in opposite directions. In contrast thereto, the insertion sections 31 are arranged parallel to each other. In particular, the engagement counter elements 28a, 28b can be configured to be mirror-symmetrical in relation to a symmetry axis 35. The symmetry axis 35 is oriented in the flow direction L and divides the wall section 24 into surfaces F1, F2 of approximately same size.

[0112] The engagement elements 22a to 22d, together with their hold sections 29a to 29d, are presently designed as separate parts, i.e., in the unmounted state (FIG. 6) they are neither connected to the filter housing 7 nor to the filter element 8. Instead, they are connectable detachably to the filter element 8 and the filter housing 7 in order to secure in this way the filter element 8 in its mounted position in the filter housing 7, to be explained in more detail in the following.

[0113] For example, two through holes 36 are formed in the lateral strips 11, 12, respectively. After insertion of the filter element 8 into the filter housing 7, the through holes 36 are positioned opposite the through holes 34 in the engagement counter elements 28a, 28b (step S1 of the method illustrated in FIG. 16).

[0114] In a further step, the engagement elements 22a to 22d are moved into the recessed regions 30 and from there, from the interior, pushed through the through holes 36 into the through holes 34. Correspondingly, a respective engagement element 22a to 22d is arranged at a respective lateral face 11, 12 and extends away from the filter medium body 9. Since the engagement elements 22a to 22d pass through the through hole 36 as well as the through hole 34, respectively, a form fit connection results between them and the filter housing 7 and the filter element 8 (method step S2 in FIG. 16).

[0115] Alternatively, the engagement elements 22a to 22d can be already positioned in the respective through holes 36 prior to the insertion of the filter element 8 into the filter housing 7. Then, the filter element 8, for example, by hand, is bent about an axis 37. The axis 37 extends, for example, perpendicularly to the lateral faces 11, 12. Due to this deformation (not illustrated), the through holes 36, which, in the undeformed state, have a larger distance d relative to each other than the insertion sections 31, move closer together (not illustrated). The distance between them is identified by D in FIG. 6. Correspondingly, due to the deformation, the engagement elements 22a to 22d can then be inserted into the insertion sections 31 opening up into the rim 33. Then, the engagement elements 22a to 22d are pushed along the respective insertion section 31 in the flow direction L, in FIG. 6 downwardly, until they reach the respective blocking section 32 connected to the insertion sections 31. This corresponds to method step S3 of FIG. 16.

[0116] Then, the filter element 8 is released so that it can return into its initial state. In doing so, the engagement elements 22a to 22d each move outwardly along the blocking sections 32 and engage finally with form fit the through holes 34, for which purpose pressure is applied onto the engagement elements 22a to 22d from the interior, for example, by hand.

[0117] Advantageously, the hold sections 29a to 29d are accessible from the mounting side, from which the filter element 8 is inserted into the filter housing 7 and which presently corresponds to the raw side RO, and can be moved for demounting the filter element 8 simply by hand inwardly so that the engagement elements 22a to 22d become disengaged from the through holes 34, 36.

[0118] FIG. 7A shows a filter device 6 according to a second embodiment in perspective view. FIG. 7B shows a section I-I, FIG. 7C a section II-II of FIG. 7A. FIG. 8 shows an exploded view of the second embodiment. The following explanations relate to FIGS. 7A to 8 together, wherein primarily differences in regard to the first embodiment according to FIGS. 5A to 6 will be explained.

[0119] In the second embodiment, in contrast to the first embodiment, the hold sections 29a, 29b or 29c, 29d of respective two engagement elements 22a, 22b or 22c, 22d arranged at the same lateral face 11 or 12 are connected by a respective connection piece 38. The connection piece 38 in the mounted state, as shown in FIG. 7A, is arranged parallel to the lateral face 11. In addition, it extends above fold tips or fold edges 16.

[0120] The connection piece 38 can be designed to be elastic. This applies primarily to the mounting variant in which the engagement elements 22a, 22b or 22c, 22d are guided along the insertion sections 31 of the engagement counter elements 28a to 28d because the distance between the neighboring engagement elements 22a, 22b or 22c, 22d is reduced in this case (compare the above explanations in regard to the distances d and D in connection with FIG. 6). As soon as the engagement elements 22a to 22d reach their respective blocking section 32 at the end of the respective insertion section 31, they snap elastically outwardly into the end of a respective blocking section 32. The thus provided form fit connection is secured by the respective connection piece 38 due to its elasticity or stiffness.

[0121] FIG. 9A shows in a perspective view a third embodiment of a filter device 6. FIG. 9B shows a section I-I, FIG. 9C a section II-II of FIG. 9A. FIG. 10 illustrates an exploded view of the third embodiment. In the following, reference is being had to FIGS. 9A to 10 together, wherein primarily the differences in relation to the afore described embodiments will be explained.

[0122] In contrast to the second embodiment according to FIGS. 7A to 8, in the third embodiment according to FIGS. 9A to 10, the engagement elements 22a, 22c or 22b, 22d, which are arranged at different lateral faces 11, 12 of the frame 10, are connected by a respective connection piece 38. The connection piece 38 is advantageously elastic and, as needed, additionally curved so that it secures the engagement elements 22a to 22d in their respective engagement position with the through holes 34. For this purpose, the connection piece 38 pretensions the engagement elements 22a, 22c or 22b, 22d provided at its ends in outward direction, i.e., in a direction away from the filter element 8, in the mounted state. The connection pieces 38 in this case are arranged in a direction perpendicularly to the lateral faces 11, 12. In addition, the connection pieces 38 can extend partially or completely in the recessed regions 30 (see FIG. 9C).

[0123] At the left side, FIG. 11 shows a filter element 8 with engagement elements 22a to 22d in a mounted position. The filter housing 7 is not illustrated for reasons of clarity. At the right side, the engagement elements 22a to 22d are illustrated in isolation together with connection pieces 38. In an enlarged illustration, a hold section 29a for the engagement element 22a is illustrated in an exemplary fashion in more detail.

[0124] According to the embodiment, the engagement elements 22a to 22d are embodied in the form of hooks. They are configured to engage with form fit the blocking sections 32 of the engagement counter elements 28a to 28d which are illustrated, for example, in FIG. 6. This is done in that the engagement elements 22a to 22d are pushed substantially along the flow direction L into a gap (not illustrated) between the filter element 8 and the wall section 24 or 25 (see FIG. 6). In doing so, the lateral faces 11, 12 are pushed elastically inwardly and provide then a contact pressure which holds the engagement elements 22a to 22d in engagement with the blocking sections 32.

[0125] The hold section 29a (see the enlarged view in FIG. 11) is presently embodied in an exemplary fashion in a cross shape and comprises four stays 41a to 41d. In FIG. 11, the stay 41a faces downwardly in this context. The engagement element 22a is integrally formed as one piece at its bottom end. The stay 41b faces vertically upwardly. It is embodied shorter than the stay 41a and serves, for example, as grip section for manually gripping the engagement elements 22a to 22d upon insertion or upon removal thereof in the context of mounting or demounting of the filter element 8. The stay 41c extends laterally and, for example, is also embodied shorter than the stay 41a. In relation to the engagement element 22a, the stay 41c engages an upper rim 42 of the lateral face (or of the lateral strip) 11. In this way, it is prevented that the filter element 8 can move along the flow direction L in relation to the filter housing 7. The stay 41d is also shorter than the stay 41a and engages from behind the rim 33 (see FIG. 6) of the filter housing 7. In this way, the fixation of the engagement elements 22a to 22d in the blocking sections 32 is further improved.

[0126] In the embodiment according to FIG. 11, the stays 41a to 41d form a one-piece component of the connection pieces 38. In addition, the connection pieces 38 comprise, for example, a further grip section in the form of a tab 43.

[0127] In the embodiment according to FIG. 11, a respective connection piece 38 connects two hold sections 29a, 29b or 29c, 29d or two engagement elements 22a, 22b or 22c, 22d which are arranged on the same side of a respective lateral face 11, 12. Correspondingly, the connection pieces 38 extend parallel to the lateral faces 11, 12. Two respective engagement elements 22a, 22b or 22c, 22d form together with two respective hold sections 29a, 29b or 29c, 29d and a connection piece 38 a separate part.

[0128] In contrast thereto, FIG. 12 shows an embodiment in which the connection pieces 38 connect hold sections 29a, 29c or 29b, 29d or engagement elements 22a, 22c or 22b, 22d at opposed lateral faces 11, 12 to each other. Correspondingly, the connection pieces 38 extend transversely to the lateral faces 11, 12. In addition, the connection pieces 38 extend above the fold edges 16. Two respective engagement elements 22a, 22c or 22b, 22d form with two respective hold sections 29a, 29c or 29b, 29d and a connection piece 38 a separate part. In the embodiment according to FIG. 12, the filter element 8 is completely engaged across by the hold sections 29a to 29d together with the connection pieces 38.

[0129] In the embodiment according to FIG. 13, the engagement elements 22a to 22d together with respective correlated hold sections 29a to 29d are formed as a separate part and are not connected to each other by means of connection pieces 38. Two engagement elements 22a to 22d together with correlated hold sections 29a to 29d are arranged at a lateral strip 11 or 12, respectively.

[0130] In the embodiment according to FIG. 14, the engagement elements 22a to 22d are fastened at the filter element 8, namely already prior to the first mounting step (see step S1 according to FIG. 16). In particular, the engagement elements 22a, 22b or 22c, 22d are glued to the lateral strips 11 or 12, welded thereto or formed as one piece therewith. According to the embodiment, the engagement elements are in the form of projections which project outwardly away from a respective lateral strip 11, 12, i.e., from the filter element 8. The engagement elements 22a to 22d according to FIG. 14 are, for example, embodied to engage the through holes 34 or corresponding pockets (see FIG. 6) with form fit.

[0131] In the embodiment according to FIG. 15, two respective engagement elements 22a, 22b or 22c and 22d are connected to each other by a connection piece 38, wherein the connection piece 38 is fastened, in particular glued, to a correlated lateral wall 11 or 12. The connection piece 38 in this case can also be configured to be elastic in order to permit a change of the distance d (see FIG. 6).

[0132] In this context, FIGS. 11 to 15 show a set 40, respectively, comprising a filter element 8 and engagement elements 22a to 22d. The set 40 is suitable for use with a filter housing 7, for example, as illustrated in FIG. 6. A filter element already present thereat can be exchanged by means of the set 40 in a simple manner, wherein preferably at least the steps S1 and S2 according to the method of FIG. 16, optionally also the step S3, are carried out.

[0133] Even though the present invention has been explained with the aid of some embodiments, it is not limited thereto but can be modified in many ways. Presently, a does not preclude a plurality.

REFERENCE CHARACTERS

[0134] 1 motor vehicle [0135] 2 air conditioning device [0136] 3 ambient air [0137] 4 air [0138] 5 cabin [0139] 6 filter device [0140] 7 filter housing [0141] 8 interior filter/filter element [0142] 9 filter medium/filter medium body [0143] 10 frame [0144] 11 lateral strip/lateral face [0145] 12 lateral strip/lateral face [0146] 13 head strip [0147] 14 head strip [0148] 15 fold [0149] 15a fold section [0150] 16 fold edge [0151] 17 end fold [0152] 18 end fold [0153] 19 fold end face edge [0154] 20 fold end face edge [0155] 21 seal [0156] 22a to 22d engagement elements [0157] 23 frame [0158] 24 wall section [0159] 25 wall section [0160] 26 wall section [0161] 27 wall section [0162] 28a to 28d engagement counter elements [0163] 29a to 29d hold sections [0164] 30 recessed region [0165] 31 insertion section [0166] 32 blocking section [0167] 33 rim [0168] 34 through hole [0169] 35 symmetry axis [0170] 36 through hole [0171] 37 bending axis [0172] 38 connection piece [0173] 40 set [0174] 41a to 41d stays [0175] 42 rim [0176] 43 tab [0177] A1, A2 distances [0178] D distance [0179] d distance [0180] E plane [0181] F1, F2 surfaces [0182] H, H=height [0183] L flow direction [0184] M machine direction [0185] RO raw side/inflow side [0186] RE clean side/outflow side [0187] S1, S2, S3 method steps