Patent Publication Number: US-2023158433-A1

Title: Filter Element for an Air Filtration Device of a Motor Vehicle and Air Filtration Device

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     The invention relates to a filter element for an air filtration device of a motor vehicle, with a frame which at least partially surrounds a filter material. The frame comprises an elastically deformable front wall, which extends substantially perpendicular to an insertion direction. The filter element can be inserted into a receiving chamber of a housing of the air filtration device, in the insertion direction. At least one fastening element is arranged on the frame. A lid of the air filtration device can be fixed on the at least one fastening element, the lid being designed for the closure of the receiving chamber. Furthermore, the invention relates to an air filtration device with such a filter element. 
     DE 10 2017 007 497 A1 describes a filter element for an air filtration device of a motor vehicle, wherein a filter material is bordered by a frame. The frame has a front wall which extends perpendicular to an insertion direction, in which the filter element is inserted into a housing of the air filtration device. On both sides of the front wall, which are perpendicular to the insertion direction and opposite to one another, respective fastening elements are arranged, which are connected with the front wall by means of a connecting bar. Through-openings are formed in the fastening elements, into which latch pins are inserted. The latch pins are positioned rotationally on a lid of the air filter housing. If the filter element is inserted into the air filter housing, the latch pins can be guided through the through-openings and twisted, so that the lid is fixed on the housing and the housing is thereby sealed. The front wall can be elastically deformed or compressed in order to introduce the filter element into the housing. For the purpose of this compression of the front wall, respective actuating plates are arranged on the fastening elements, which can be moved towards one other. While the front wall is elastically deformed in this way, the filter element can be inserted into the housing. If the actuating plates are then released again, the fastening elements then engage behind webs, which are formed on the respective walls of the housing. 
     Such an embodiment of the filter element entails a pressure having to be simultaneously applied from the outside on both actuating plates during the elastic deforming of the front wall, while the filter element attached to the frame is inserted into the housing. This makes the handling of the filter element somewhat cumbersome. 
     It is therefore the object of the present invention to provide a filter element of the kind mentioned above, which can be particularly easily integrated into a housing of an air filtration device, and to specify an air filtration device with such a filter element. 
     The filter element according to the invention for an air filtration device of a motor vehicle has a frame which at least partially surrounds a filter material of the filter element. The frame comprises an elastically deformable front wall. The front wall extends perpendicular to an insertion direction, in which the filter element can be inserted into a receiving chamber of a housing of the air filtration device—also referred to in the following as “air filter housing” or “housing.” At least one fastening element is arranged on the frame. A lid of the air filtration device can be fixed on the at least one fastening element, the lid being designed for the closure of the receiving chamber. Furthermore, at least one insertion bevel is formed on the frame, by means of which the front wall can be brought into an elastically deformed state during the insertion of the filter element into the receiving chamber. In the elastically deformed state, a longitudinal dimension of the front wall is smaller than in an original state of the front wall, in which the front wall is not deformed, and due to this feature, the front wall can be held indented in the receiving chamber of the housing by a housing opening that is narrower in comparison to the front wall of the filter element. 
     The fastening element that is formed integrally with the insertion bevel is provided by an inherently rigid component, which is mounted on the frame of the filter element in the area of the front wall. Thus, on the one hand, a force applied to the insertion bevel is directly employed to elastically deform the front wall when introducing the filter element into the receiving chamber through the housing opening and, on the other hand, a good closure element can work well with the fastening element, the closure element ensuring the attachment or retention of the lid on the air filter housing. 
     The insertion bevel formed on the frame thus automatically ensures the elastic deformation of the front wall when introducing the filter element into the receiving chamber, the front wall springing back into its original shape as soon as the filter element has reached its installation position, whereby the filter element is held in the housing with an indent. No particular actuating plates or similar are needed in order to compress or elastically deform the front wall in the longitudinal direction, which runs perpendicular to the insertion direction and perpendicular to the height of the front wall. Rather, it is sufficient to introduce the filter element into the receiving chamber in the insertion direction, wherein the insertion bevel then causes the elastic deformation of the front wall. This is because the force acting on the insertion bevel during the insertion or introduction into the air filter housing inevitably ensures that the front wall is brought into an elastically deformed state. As a result, the filter element can easily be installed into the housing and secured therein. 
     For the filter element having the at least one insertion bevel, it is in particular advantageous that the air filtration device of the motor vehicle can only then be operated if the filter element is installed or integrated into the receiving chamber. This is because the at least one fastening element, which is part of the filter element, is necessary for fixing the lid of the air filtration device to the air filter housing. In other words, the attachment of the lid to the housing is not possible if the filter element is not integrated into the receiving chamber of the housing. Incorrect operation of the air filtration device can thereby be prevented. 
     Because the at least one fastening element is formed integrally with the insertion bevel, it is simultaneously ensured that the at least one fastening element is aligned in the correct position for the mounting or attachment of the lid on the air filter housing, as long as the filter element is brought into its installation position, which is indented relative to the housing. 
     For a secure attachment of the lid to the air filter housing, it is sufficient if simply one or precisely one fastening element is arranged on the frame of the filter element, the fastening element serving for the affixing or attachment of the lid. This also simplifies the attachment of the lid to the housing, as only one closure element needs to work with the fastening element in order to close the receiving chamber, by means of the lid. The filter element can thereby be so inserted, that it is first introduced through the housing opening into the receiving chamber diagonal to the side opposite to the side wall of the frame, which has the insertion bevel and the component that supports the fastening element, and the filter element is secured behind a housing projection, and the corner with the insertion bevel is subsequently introduced into the receiving chamber. 
     It may in particular be provided that the fastening element protrudes from the front wall counter to the insertion direction. This guarantees a good accessibility of the fastening element for a closure element of the lid. In particular, the fastening element can be encompassed by the closure element of the lid. 
     Preferably, the insertion bevel is wedge-shaped, due to which the insertion bevel has a greater width in the direction of the longitudinal dimension of the front wall in an end region near the front wall than in an end region of the insertion bevel that is far away from the front wall, which is formed by at least one guide slope that is aligned diagonally to a side wall of the frame. By using a wedge-shaped insertion bevel of this kind, the elastic deforming of the front wall when inserting the filter element into the receiving chamber can be effectively achieved. This is because the wedge-shaped insertion bevel is inherently rigidly formed, which ensures that a force which acts on roughly at least one diagonally aligned guide slope of the insertion bevel consistently leads to a deformation—or a yielding—of the elastic front wall. 
     Preferably, the insertion bevel and the component that comprises the fastening element have a locating flange, which lies on the front wall, as well as a base part, which lies on the side wall of the frame. A stable connection with the filter element, or with the frame of the filter element, is ensured by the flat connection of the component to the front wall and side wall. In this way, the assembly is durable against being acted on by forces, on one side by the insertion bevel, on the other side by the fastening element. 
     Preferably, the insertion bevel comprises a stiffening element, which is arranged between the base part and the at least one guide slope of the insertion bevel. The insertion bevel thereby obtains the necessary stiffness in a material-saving way, with a filigree construction. 
     Preferably, the insertion bevel has an end face, by which an abutment is provided. The abutment is designed to engage behind a supporting element of the air filter housing for the filter element integrated into the receiving chamber. It can thereby be ensured that then, if the supporting element of the housing lies on the abutment, the filter element cannot be unintentionally removed from the receiving chamber. 
     This is then in particular advantageous if the filter element should be installed upside down, so needs to be inserted into the receiving chamber against gravity. This is because the abutment that is provided through the end face of the insertion bevel ensures that the filter element that is arranged in the receiving chamber does not move back out of the receiving chamber as a result of gravity. The filter element therefore does not need to be fixed manually or by means of another aid before the lid is attached to the housing. Instead, the indented arrangement of the abutment on the supporting element already secures the filter element in its position in the receiving chamber, while the lid is then secured or fixed to the fastening element in order to close the receiving chamber. 
     A particularly compact embodiment of the filter element can be achieved if the end face of the insertion bevel is aligned with the front wall. Additionally, the insertion bevel then very directly introduces the force into the front wall, which causes the elastic deformation of the front wall. 
     It has been shown that it is furthermore advantageous if the at least one fastening element has at least one supporting part, which, when the lid is fixed to the air filter housing, is engaged from behind by a corresponding supporting part of the lid. A very secure fixing of the lid to the housing by means of the at least one fastening element can thereby be achieved. 
     The at least one supporting part can in particular be formed in the manner of a bar or wing that protrudes from a basic body of the fastening element parallel to the front wall, which can be engaged from behind by the corresponding supporting part of the lid. This is because a wing of this kind is very easily accessible for the corresponding supporting part. 
     In particular, if a wing of this kind has a ramp-like shape in an end region, on which the corresponding supporting part is moved along during the fixing of the lid, a very tight-fitting arrangement of the lid on the housing can be achieved. 
     The air filtration device according to the invention for a motor vehicle has a filter element according to the invention, wherein the filter element is integrated into a receiving chamber which is formed in a housing of the air filtration device. 
     The air filtration device can in particular be formed as an air filtration device of an air conditioner or ventilation device of the motor vehicle. Moreover, the air filtration device can be provided for an intake of an internal combustion engine of the motor vehicle, i.e., as a filter for the air drawn in by an internal combustion engine. 
     Preferably, the receiving chamber can be closed by means of a lid of the air filtration device, wherein the lid can be fixed to the at least one fastening element of the filter element. In this way it is ensured that the receiving chamber can only be closed by means of the lid when the filter element is correctly installed in the air filter housing. 
     Preferably, an intake is formed on at least one housing wall of the housing, in which the at least one fastening element is accommodated. The intake thereby comprises a supporting element, which lies on an end face of the insertion bevel of the filter element. Thus, when the filter element is introduced or integrated into the receiving chamber of the housing, the end face, more precisely the part of the end face that forms the abutment of the insertion bevel, is engaged from behind by the supporting element of the intake, and a prefixing of the filter element in the receiving chamber of the housing is achieved. The filter element can therefore not unintentionally come out of the receiving chamber. 
     This is then in particular important if the filter element is integrated into the receiving chamber against gravity during its insertion into the housing, the receiving chamber being formed in the air filtration housing. An upside-down installation of the filter element is thereby enabled, namely in a particularly simple manner. 
     The lid preferably has a closure element, which is rotatable relative to a basic body of the lid. In a closed position of the closure element, at least one supporting part of the closure element thereby engages behind a corresponding supporting part of the fastening element. In this way, a particularly secure fixing of the lid to the housing can be achieved, due to the interaction of the closure element with the fastening element. In particular, the closure element can be formed in the manner of a rotary closure. 
     The advantages described for the filter element according to the invention and preferred embodiments also apply for the air filtration device according to the invention, and vice versa. 
     Further advantages, features and details of the invention arise from the following description of preferred exemplary embodiments as well as from the drawings. The preceding features and combinations of features referred to in the description as well as the features and combinations of features referred to in the figure description and/or only illustrated in the figures hereinafter can be used not only in the respective combinations indicated, but also in other combinations or alone, without leaving the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a filter element for an air filtration device of a motor vehicle, in a schematic perspective view; 
         FIG.  2    shows a section of a region of a frame of the filter element in a magnified detail view, in which a component is arranged on the frame, by which an insertion bevel and a fastening element are provided; 
         FIG.  3    shows the component shown in  FIG.  2   , in a magnified perspective view; 
         FIG.  4    shows the elastic deformation of a front wall of the frame of the filter element due to an application of force to the component from the side; 
         FIG.  5    shows an air filter housing into which the filter element can be introduced according to  FIG.  1   , in a sectional and a perspective view; 
         FIG.  6    shows a section of the housing according to  FIG.  5   , in a partially cut view; 
         FIG.  7    shows a lid of the air filtration device, by means of which a receiving chamber for the filter element according to  FIG.  1   , which is formed in the housing according to  FIG.  5   , can be sealed, in a sectional view; 
         FIG.  8    shows a magnified view of an underside of the lid according to  FIG.  7   ; 
         FIG.  9    shows a first step during an insertion of the filter element according to  FIG.  1    into the housing according to  FIG.  5   , in a partially cut perspective view; 
         FIG.  10    shows a second step during inserting the filter element according to  FIG.  1    into the housing according to  FIG.  5   , in a partially cut perspective view; 
         FIG.  11    shows the elastic deformation of the front wall of the filter element according to  FIG.  1   , due to the application of a force to the insertion bevel of the component shown in  FIG.  3   ; 
         FIG.  12    shows the bouncing back of the front wall to its non-deformed original state, in which a supporting element formed on the side of the housing is engaged from behind by the component; 
         FIG.  13    shows a first step in the attachment of the lid according to  FIG.  7    to the housing according to  FIG.  5   , wherein the filter element according to  FIG.  1    is arranged in the receiving chamber of the housing; 
         FIG.  14    shows the fitting of the lid onto the housing and the rotation of a closure element of the lid that is formed as a rotary closure; 
         FIG.  15    shows the housing with in-built filter element and lid that is fixed to the housing, in a partially cut and sectional view; 
         FIG.  16    shows the state of the air filtration device according to  FIG.  14   , in a partially cut top view; and 
         FIG.  17    shows the state of the air filtration device according to  FIG.  15   , i.e., with a rotary closure that is moved into a closed position, in a partially cut top view. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     In the figures, identical or functionally identical elements are provided with the same reference numerals. 
     A filter element  10  is shown in a schematic perspective view in  FIG.  1   , which is intended for installation in a housing  12  (see  FIG.  5   ) of an air filtration device of a motor vehicle. A receiving chamber  14  (see  FIG.  5   ) is formed in the housing  12  of the air filtration device, in which receiving chamber the filter element  10  shown in  FIG.  1    can be integrated or installed. 
     The filter element  10  comprises a frame  16 , which surrounds or borders a filter material  18  of the filter element  10 . When the filter element  10  is formed as a pleated filter, the filter material  18  can have a plurality of pleats, as is exemplarily shown herein. However, other embodiments of the filter material  18 , through which air can flow during the operation of the filter element  10 , are also possible. 
     The frame  16 , which, in the present case, completely surrounds or encloses the filter material  18  on its periphery, comprises a front wall  20  and, in the present case, a back wall  22  that lies opposite to the front wall  20 . The front wall  20  and the back wall  22  are connected to one another by two side walls  24 ,  26  of the frame  16 . 
     The filter element  10  can be inserted into the receiving chamber  14  (see  FIG.  5   ) in an insertion direction  28 , which is illustrated in  FIG.  1    by an arrow. The side walls  24 ,  26  consequently extend from the front wall  20 , going outwards in the insertion direction  28  towards the back wall  22 . The frame  16  is therefore essentially formed as a rectangle in the present case, wherein, depending on the shape of the receiving chamber  14 , other shapes of the frame  16  are also possible. 
     In the region of the front wall  20 , a component  30  is arranged on the frame  16 , which is shown in  FIG.  2    in a magnified detail view of the frame  16  and in  FIG.  3   , again in perspective view and separate from the frame  16 . 
     A fastening element  32  is firstly provided by the component  30 , the fastening element serving to fix a lid  34  (see  FIG.  7   ) to the housing  12 . Furthermore, an insertion bevel  36  is provided by the component  30 , the function of which insertion bevel is explained in more detail using  FIG.  4   . 
     The present fastening element  32 , which is formed in the manner of a pin  38  with supporting parts in the shape of a first wing  40  and of a second wing  42 , protrudes from a front side  44  of the front wall  20 . The lid  34  can be fixed to the wings  40 ,  42  of the fastening element  32  that are distanced from the front wall  20  by means of a closure element formed as a rotary closure  46  (see  FIG.  7   ). The fastening element  32  therefore ensures that the lid  34  can only be attached to the housing  12  if the filter element  10  is installed in the housing  12 , and namely in that the lid  34  is fixed to the fastening element  32  of the filter element  10 . 
     Furthermore, a pre-fixing of the filter element  10  in the receiving chamber  14  of the housing  12  is achieved by means of the component  30  that has the insertion bevel  36 , as long as the lid  34  is not yet fixed to the housing  12  (see  FIG.  12    and  FIG.  13   ). 
     The insertion bevel  36  of the component  30  initially ensures an elastic deformation of the front wall  20  during the introduction or insertion of the filter element  10  into the receiving chamber  14  formed in the housing  12  (see  FIG.  5   ) in the insertion direction  28 , since the insertion bevel  36  extends the filter element  10  towards a specified entrance width of the fixed receiving chamber  14 , so that during insertion, a force or a pressure is exerted on the insertion bevel  36 , which acts on the front wall  20  of the filter element. The corresponding compression of the front wall  20  is shown in  FIG.  4   . The compression or the elastic deformation of the front wall  20  is thereby effected by a force exerted on the insertion bevel  36 , which is illustrated by an arrow  48  in  FIG.  4   . 
     In the elastically deformed or compressed state of the front wall  20 , a longitudinal dimension  50  that is occupied by the front wall  20 , perpendicular to the insertion direction  28  (see  FIG.  1   ) is smaller than in an original state of the front wall  20 , in which the front wall  20  is not deformed. The shortened longitudinal dimension  50  of the frame  16  perpendicular to the insertion direction  28  in the region of the front wall  20  is, as is schematically shown in  FIG.  4   , in particular caused by the front wall  20  being bent or deformed towards the filter material  18  and/or away from the filter material  18 . This respective elastic deformation of the front wall  20  in this way is herein caused by the insertion bevel  36 , which is provided by the component  30 . The insertion bevel  36  is, together with the filter element  10 , forced through a narrow opening of the housing  12  into the receiving chamber  14 , in which sufficient space is once again available so that the filter element  10  can expand back into its original shape. 
     For example, the insertion bevel  36  can comprise two guide slopes  52 ,  54  (see  FIG.  3   ), which are aligned diagonally to the side wall  24  (see  FIG.  4   ), in the end region of which the component  30  is attached to the front wall  20 . The force (see arrow  48 ) is herein applied to these guide slopes  52 ,  54 , which causes the compression or elastic deformation of the front wall  20 . 
     The insertion bevel  36  in the present case furthermore comprises a plate-shaped base part  56 , which lies on the side wall  24  of the frame  16  (see  FIG.  2    and  FIG.  4   ). A stiffening element  58  of the insertion bevel  36  is arranged between the base part  56  and the guide slopes  52 ,  54  (see  FIG.  3   ). This means that the insertion bevel  36  is given an overall high stiffness or rigidity. In other words, the guide slopes  52 ,  54  cannot be moved towards the plate-shaped base part  56  if the front wall  20  has the force applied to it in the region of the component  30 , perpendicular to the insertion direction  28  or in the direction of the longitudinal dimension  50 , which is illustrated in  FIG.  4    by the arrow  48 . 
     The insertion bevel  36  and respectively the component  30  additionally has a locating flange  60 , which extends along the front wall  20  and abuts the front side  44  of the front wall  20 , or rests on the front side  44  of the front wall  20 . 
     An upper side  62  of the locating flange  60  and of the stiffening element  58  are associated with an end face of the insertion bevel  36 , which is flush with the front wall  20 . Abutments  64  are provided in the region of the guide slopes  52 ,  54  by this end face of the insertion bevel  36 . The abutments  64  engage behind a respective supporting element  66 , which is provided or formed on the side of the air filter housing  12  (see  FIG.  5    and  FIG.  6   ), when the filter element  10  is integrated into the receiving chamber  14 . 
     In this regard it is in particular apparent from  FIG.  6    that the respective supporting element  66  is associated with an intake that is formed as a holding recess  68 , into which the shaft or pin  38  of the fastening element  32  can be introduced, together with the wings  40 ,  42 . In this context, the supporting elements  66  are formed in the manner of arms, which partially delimit a receiving chamber of the holding recess  68  in the peripheral direction, in which the fastening element  32  can be arranged. 
     The holding recess  68 , which serves as the intake for the fastening element  32 , is formed on a side housing wall  82  of the housing  12  in the present case. The holding recess  68  can in particular be formed integrally with the housing wall  82  (see  FIG.  5    and  FIG.  6   ), which delimits the receiving chamber  14  on one side. 
     In  FIG.  7   , the lid  34  of the air filtration device is shown, in an external view. Therefore, the lid  34  comprises a basic body  70  and the rotary closure  46  that is rotatable relative to the basic body  70 . 
     In  FIG.  8   , the rotary closure  46  is shown in a view of its underside, which is facing the receiving chamber  14 . Likewise, in  FIG.  8   , that side of the basic body  70  of the lid  34  can be seen, which is facing the receiving chamber  14  when the lid  34  is fixed to the housing  12 . Therefore, the lid  34  can have a sealing element  72  on this underside. 
     Moreover, it is apparent in  FIG.  8    that recesses  74  are formed in the rotary closure  46 , the contours of which correspond to a respective contour of the wings  40 ,  42  that are formed on the fastening element  32  (see  FIG.  3   ). 
     The installation of the filter element  10  in the air filtration device, or the integration of the filter element  10  into the receiving chamber  14  of the air filter housing  12 , in such a way that the fastening element  32  enters the holding recess  68  and the abutments  64  thereby engage behind the respective supporting elements  66  of the holding recess  68 , is explained in the following, referencing  FIG.  9    to  FIG.  12   . 
     According to  FIG.  9   , the filter element  10  is introduced into the housing  12  in the insertion direction  28 . In this way, each one of the guide slopes  52 ,  54  enters into contact with a respective supporting element  66  of the holding recess  68  (see  FIG.  10   ). The force that is applied to the insertion bevel  36  during the further insertion in the insertion direction  28  causes the elastic deformation of the front wall  20 . This is exaggeratedly shown in  FIG.  11   , wherein the force acting on the insertion bevel  36  is illustrated in  FIG.  11    as well as in  FIG.  4    by the arrow  48 . 
     The front wall  20  that is compressed or elastically deformed according to  FIG.  11    then reassumes its original state according to  FIG.  12   , in which the front wall  20  is not deformed, rather it is aligned straight again. Due to the front wall  20  snapping back into its original state, the abutments  64  go behind the supporting elements  66  that are formed in the area of the holding recess  68 . The insertion bevel  36  thereby undercuts the holding recess  68  in a tight fit. The filter element  10  has then attained the predetermined final position in the receiving chamber  14  of the housing  12 . 
     With the attainment of the final position of the filter element, the abutments  64  therefore latch behind the supporting elements  66  with an undercut, the supporting elements being formed on the holding recess  68 . In this way, the wings  40 ,  42  are also aligned in the correct position, whereby a clamping geometry and a holding geometry of the fastening element  32  are provided, and the lid  34  can be mounted. 
     This fastening of the lid  34  to the housing  12  is illustrated with reference to  FIG.  13    to  FIG.  15   . According to the sectional view in  FIG.  13   , the lid  34  is first attached to the housing  12 , wherein the recesses  74  of the rotary closure  46  that correspond with the wings  40 ,  42  interlock. Then, the rotary closure  46  can be gripped and rotated (see  FIG.  14   ) on a bar or similar handle part  76  (see  FIG.  7   ). 
     The two supporting parts  78  (see  FIG.  8   ) of the rotary closure  46  are, then, thereby also turned with it, so that that they engage behind the wings  40 ,  42  on the pin  38  on the component  30  of the filter element  10 . This turning of the rotary closure  46  is represented in  FIG.  14   , wherein a direction of rotation of the rotary closure  46  is illustrated by a curved arrow  80 . In  FIG.  15   , the rotary closure  46  is then shown in its closed position. 
     By the supporting parts  78  of the rotary closure  46  engaging behind the wings  40 ,  42  of the fastening element  32 , the lid  34  is herein brought into a tightly fitting position on the housing  12 . This is because the abutments  64 , which are provided on the end face of the insertion bevel  36  (see  FIG.  3   ), lie on the supporting elements  66  of the holding recess  68 . 
     The supporting parts  78  of the rotary closure  46  correspond to the wings  40 ,  42 , which form the clamping geometry and the holding geometry of the fastening element  32 . In this regard it is in particular apparent in  FIG.  3    that the wings  40 ,  42  can be formed in a tapering, ramp shape going against the direction of rotation of the rotary closure  46 , which is illustrated in  FIG.  14    by the arrow  80 . Therefore, the supporting parts  78  of the rotary closure  46  run aground on the respective ramps of the wings  40 ,  42  if the supporting parts  78  engage behind the wings  40 ,  42  and the rotary closure  46  is turned further in the direction of rotation that is illustrated by the arrow  80 . A particularly high tightness between lid  34  and housing  12  is thereby attained, as the fastening element  32  that is held on the supporting element  66  of the housing  12  with an undercut and the ramp-shaped wings  40 ,  42  cause the lid  34  to be pulled towards the housing  12  during the tightening of the supporting parts  78 . 
     In  FIG.  16   , the lid  34  is shown intersected in the region of the rotary closure  46 . In this way, the alignment of the rotary closure  46  that the rotary closure  46  has in  FIG.  14    is illustrated in  FIG.  16   . This means the supporting parts  78  still do not engage behind the wings  40 ,  42 . 
     In  FIG.  17   , the rotary closure  46  is, by contrast, shown in its closed position, in which the supporting parts  78  engage behind the wings  40 ,  42 . The undercut that is thereby achieved ensures a tightly fitting fixation of the lid  34  to the housing  12 , due to the interaction of the rotary closure  46  with the fastening element  32 . 
     During disassembly, the rotary closure  46  is brought back into its open position, that is shown in  FIG.  14   . The lid  34  can then be taken off the housing  12 . Finally, the filter element  10  can be taken out of the receiving chamber  14 , wherein the front wall  20 , as is schematically shown in  FIG.  4   , is elastically deformed again, which can, for example, happen due to a manual intervention in the filter material  18 , by means of the filter material  18  being contracted, together with the front wall  20  that is adhered to it.