Abstract:
An air filter device for a motor vehicle, having a filter element received in a filter housing which, at least in sections, is surrounded by an encompassing frame part. A support bead is held on the filter housing which protrudes over the directly adjacent filter housing wall, wherein a sealing element on the frame is supported by the support bead on the housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of German patent application No. 10 2013 015 496.0 filed Sep. 19, 2013, the entire contents of the aforesaid German patent application being incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The invention relates to an air filter device, particularly for a motor vehicle, according to the preamble of claim  1 . 
       BACKGROUND 
       [0003]    From DE 10 2011 011 595 A1, an air filter device for a motor vehicle is known, which has a filter element insertable in a filter housing and which is connected to a frame part on its inflow front side. The frame part protrudes over the lateral surface of the filter element in lateral direction and acts as a support on the front-side edge of the filter housing. The frame part is pressed against the filter housing by a placed lid which is to be connected to the filter housing by means of tension clamps. Air is supplied through the lid which is designed as a two-part cyclone separator. 
         [0004]    From U.S. Pat. No. 6,117,202, an air filter device for clean rooms is known which has a pleated filter element with a lateral frame part which, in the region of a front side, is designed so as to be U-shaped and to receive a sealing element. A protrusion of a filter housing, into which the filter element is inserted, extends into the U-shaped receiving space with the sealing element arranged in said receiving space. 
       SUMMARY OF THE INVENTION 
       [0005]    The invention addresses the problem of providing a flow-tight and durable connection between an air filter element and a receiving filter housing with simple constructive measures. 
         [0006]    The air filter device according to the invention is used, for example, in motor vehicles for filtering the combustion air to be supplied to the internal-combustion engine. A use in trucks as well as passenger cars is conceivable. 
         [0007]    The air filter device has a filter housing and a filter element insertable in the filter housing, the filter element being to some extent or entirely surrounded by an encompassing frame part. The frame part is preferably located on a front side of the filter element, particularly on the inflow front side. 
         [0008]    On the frame part, a sealing element is arranged with a support bead associated thereto on the filter housing. The sealing element sealingly bears against the support bead on the housing, thus providing a flow-tight connection between the sealing element on the filter element and the support bead on the housing and thus preventing faulty airflows. The support bead protrudes over the directly adjacent sections of the filter housing wall, on which the support bead is arranged, and therefore the support bead presses into the material of the sealing element. This is advantageous because it reduces the risk of shearing the sealing element in case of a relative movement between filter element or frame part and filter housing. Furthermore, this also prevents a part of the sealing element to get caught between the filter housing and the frame part, which could lead to a diminished sealing effect and possible destruction of the sealing element. 
         [0009]    According to an advantageous embodiment, the support bead has, at least in the section protruding into the sealing element, a smaller width than the sealing element, and therefore, the support bead, centrally acting on the sealing element, has a lateral distance to the frame part wall sections which encompass the sealing element. Thus, there is only one sealing support between the sealing element and the support bead. 
         [0010]    According to a further advantageous embodiment, the sealing element is received in a continuous receiving space on the frame part which is outwardly open. The frame part has two limbs which are spaced apart and laterally delimiting the receiving space and preferably integral with the frame part. On the frame part, the receiving space forms a continuous groove, in which the sealing element, which is preferably designed so as to be one piece and continuous, is inserted. Advantageously, the sealing element, in its unloaded state, does not protrude over the front sides of the laterally delimiting limbs of the receiving space. Together with the protruding support bead, this results, in sealing position, in the support bead to protrude into the sealing material while the front side of the sealing element simultaneously extends, at maximum, to the front sides of the delimiting limbs of the receiving space. As a result, support and sealing is provided along the connecting line of sealing element and support bead as well as in transverse direction hereto by means of the section of the support bead protruding into the sealing element. 
         [0011]    The support bead is securely arranged on the wall of the filter housing. A one-piece design with the support bead forming a protruding section on the wall of the filter housing as well as a two-piece design with the support bead designed as separate component, which is still securely connected to the wall of the filter housing, are conceivable. 
         [0012]    For example, the support bead has a mushroom shape, wherein the mushroom cap is located on the side facing away from the sealing element, and the mushroom stalk makes contact with the sealing element. Advantageously, the support bead is designed so as to be rounded on the side facing the sealing element, for example, partially circular, thus reducing the risk of cutting into the material of the sealing element. Instead, the rounded front side supports a compressing of the sealing element. 
         [0013]    According to a further advantageous embodiment, the support bead is designed so as to be continuous on the filter housing, as well as the sealing element which is arranged on the frame part. As a result, a sealing on all sides between the filter element and the receiving filter housing is achieved. 
         [0014]    According to a further expedient embodiment, the continuous frame part forms a receiving space for an air channel which is part of the air flow path through the air filter device. The frame part receives the air channel and connects it with the filter element. The air channel is preferably used to supply raw air to the raw or inflow side of the filter element; however, it is also possible to arrange the air channel on the clean or outflow side of the filter element, thus being designed as clean air channel. 
         [0015]    According to a further advantageous embodiment, the frame part, in its mounted state, is at least to some extent arranged on the outer side of the filter housing. This allows for a direct connection of the air channel with the frame part. Furthermore, the external section of the frame part can be used for connecting with the filter housing. Therefore, the frame part has two functions: Connecting the filter element with the filter housing and connecting the air channel with the filter element. An additional fastening device for fastening the air channel to the filter housing is not required. 
         [0016]    The frame part can be adhesively bonded to the filter element. For the adhesive bonding, a liquid adhesive is used, which, in its uncured state, is filled into an adhesive receiving space located between the frame part and the filter element. In order to prevent the liquid adhesive from flowing along the outer side of the filter element before it is cured, a sealing lip is advantageously located between the frame part and the filter element which delimits the adhesive receiving space between frame part and filter element. The sealing lip prevents an uncontrolled flow of the liquid adhesive during the bonding process between frame part and filter element. The sealing lip can also remain on the filter element and/or frame part even after completion of the bond and be inserted into the filter housing together with those components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    Further advantages and expedient embodiments can be found in the further claims, the description of the figures, and the drawings. 
           [0018]      FIG. 1  shows a perspective view of an air filter device for a motor vehicle, having a filter housing and a filter element inserted on the front side, which is surrounded by a continuous frame part, by means of which the filter element is held on the filter housing; 
           [0019]      FIG. 2  shows a cube-shaped filter element with front-side frame part; 
           [0020]      FIG. 3  shows a depiction corresponding to  FIG. 1  but with an air channel inserted into the frame part of the filter element; 
           [0021]      FIG. 4  shows a longitudinal cross-section through the air filter device according to  FIG. 3 ; 
           [0022]      FIG. 5  shows a front-side view of the air filter device in the region of the inflow side of the filter element; 
           [0023]      FIG. 6  shows a perpendicular cross-section through the air filter device; 
           [0024]      FIG. 7  shows detail VII from  FIG. 4  in magnified depiction with a sealing element on the frame part, with a support bead on the housing associated with said frame part, and a sealing lip which delimits an adhesive receiving space between frame part and filter element; 
           [0025]      FIG. 8  shows detail VIII from  FIG. 6  in magnified depiction with the sealing element on the frame and the support bead on the housing; 
           [0026]      FIG. 9  shows detail IX from  FIG. 3  with a tension clamp for securing the frame part on the filter housing; 
           [0027]      FIG. 10  shows detail X from  FIG. 3  with a depiction of the air channel interlockingly connected to the frame part. 
       
    
    
       [0028]    In the drawings, the same components are denoted with the same reference signs. 
       DETAILED DESCRIPTION 
       [0029]    The drawings show an air filter device  1  for a motor vehicle, for example, a truck, which is used for filtering the combustion air to be supplied to the internal-combustion engine. In a filter housing  2 , the air filter device  1  has a filter element  3  which is surrounded in the region of its front-side inflow side by a continuous frame part  4 . By way of example, the filter element  3  is designed as pleated filter bellow. 
         [0030]    The frame part  4  is located directly adjacent to the inflow or raw side  5  of the filter element  3  which, according to arrow  6 , is supplied with air to be cleaned. After filtration, the cleaned air exits through the clean or outflow side of the filter element and leaves the filter housing  2  through an outflow nozzle  9  according to arrow  7 . The filter element  3  is secured on the filter housing  2  by means of tension clamps  8  which connect the frame part  4  with the filter housing  2 . In the mounted state, the frame part  4  overlaps the front edge of the filter housing and extends to the outer lateral surface of the filter housing in the region adjacent to the insert opening for the filter element. 
         [0031]    As can be seen in the individual depiction according to  FIG. 2 , the filter element  3  is designed so as to be cube-shaped and has a rectangular profile. Correspondingly, the inflow side  5  of the filter element  3  and the frame part  4  are designed so as to be rectangular. The frame part  4  protrudes over the outer sides of the filter element  3 , wherein the front side of the frame part forms a support surface on the protruding section on the side facing away from the inflow side  5  which, in the mounted state, rests on the open front side of the filter housing. This support surface on the frame part  4  is denoted with reference sign  10 . 
         [0032]    In the mounted state, the frame part  4  is located at least substantially outside of the filter housing  2  ( FIGS. 1 ,  3 , and  4 ) and is connected to the filter housing  2  by means of the tension clamps  8 . In the region of the inflow side of the filter element  3 , the frame part  4  forms a receiving space for an air channel  11  ( FIGS. 3 ,  4 ) for supplying raw air to the air filter device  1  according to arrow  6 . The air channel  11  is inserted in the receiving space in the frame part  4  and interlockingly connected to the frame part  4  using an interlocking connection  12 . The interlocking connection  12 , shown in detail in  FIG. 10 , comprises recesses  13  in the frame part  4  and elastic snap-in noses  14  on the outer side of the air channel  11  facing the front side. The snap-in noses  14  can be pressed elastically inward in radial direction, thereby allowing for the air channel  11  to be inserted until the snap-in noses  14  interlockingly engage in the recesses  13 . The interlocking connection  12  can also be released by radially pressing the snap-in noses  14  outward from the recesses  13  in the same manner. The air channel  11  and the frame part  4  are solely connected by means of the interlocking connection  12  and between these two components. However, a connection between the air channel  11  and the filter housing  2  is not provided. The interlocking connection  12  is located directly outside of the front-side opening in the filter housing  2 . 
         [0033]      FIGS. 7 and 8  show a sealing arrangement between the frame part  4  and the filter housing  2 . The sealing arrangement comprises a sealing element  15  which is placed in a continuous receiving space  16  on the frame part  4 . The receiving space  16  is designed so as to be open on the front side facing the filter housing  2  and is delimited by two limbs  17  and  18  which are spaced apart and designed so as to be integral with the frame part  16 . 
         [0034]    A support bead  19 , which acts together with the sealing element  15 , is located on the filter housing  2 . The support bead  19  can be designed so as to be integral with the filter housing  2  or a separate component which can be made of a different material than the filter housing but is securely connected to the filter housing  2 . The profile of the support bead  19  is mushroom-shaped, wherein a narrower stalk of the support bead  19  is facing the sealing element  15  and is in contact with said sealing element  15 . The limb of the support bead  19  has a smaller width than the sealing element  15  and acts centrally on the sealing element  15 . This design is sufficiently flow-tight and the risk of shearing in the region of the sealing element  15  is significantly reduced. Advantageously, the sealing element  15  lines up with the front side of the limbs  17 ,  18 , and so no shearing is possible in the region of the front side of the sealing element  15  even in case of a relative movement between the frame part  4  and the filter housing  2 . 
         [0035]    The support bead  19  protrudes over the directly adjacent walls of the filter housing  2  and presses into the pliable material of the sealing element  15 . The front side of the stalk of the support bead  19 , which protrudes into the sealing element  15 , is designed so as to be rounded. 
         [0036]    Furthermore,  FIGS. 7 and 8  in conjunction with  FIGS. 5 and 6  show that the frame part  4  is adhesively bonded with the filter element  3 . Adhesive bonding is effected by means of continuously arranged adhesive application  20  which is filled into an adhesive receiving space  21  between the frame part  4  and the filter element  3 . The adhesive is filled in its liquid state during the manufacturing process and subsequently cures. In order to prevent the adhesive  20  to flow downward from the adhesive receiving space  21  during the curing process, a sealing lip  22  is arranged on the adhesive receiving space  21  with its approximately triangular profile ( FIGS. 5 ,  7 ). The sealing lip  22  is securely connected to the frame part  4  and remains arranged on the frame part  4  even in the cured state of the adhesive  20 . 
         [0037]    The adhesive receiving space  21  is, relative to the receiving space  16  for receiving the sealing element  15 , arranged so as to be offset radially inward and, relative to the receiving space  16  for the sealing element  15 , separated from the limb  18  which simultaneously laterally delimits the adhesive receiving space  21 . The sealing lip  22  is arranged at the foot of the limb  18  and extends obliquely inward, delimiting the tapering side of the adhesive receiving space; the free front side of the sealing lip  22  bears against the outer lateral surface of the filter element  3 . 
         [0038]    The sealing lip  22  is arranged on the two opposite longitudinal sides of the rectangular frame part  4  ( FIG. 5 ). One side band  23  each is located on the narrow faces of the filter element  3  which is securely connected to the filter element  3  and, in the region of the narrow faces, delimits the adhesive receiving space  21  toward its tapering side ( FIGS. 5 ,  6 , and  8 ). 
         [0039]      FIG. 9  shows the support of the frame part  4  on a counter contact surface on the filter housing  2  and the connection by means of the tension clamp  8 . The part of the frame part  4  which radially protrudes over the filter element has the support surface  10  (see also  FIG. 2 ) which is facing away from the inflow side and in the connected state bears against the counter contact surface  24  on the filter housing. The tension clamp  8  is held pivotably movable on the outer surface of the filter housing  2 , and, in the tensioned state, overlaps the section on the housing with the counter contact surface  24  and the section of the frame part  4  with the support surface  10 . The tension clamp  8  is designed so as to be elastic; in the tensioned state, a tension section  8   a  overlaps the recess on the frame part  4 , on which the support surface  10  is arranged and thus presses the frame part  4  with the support surface  10  against the counter contact surface  24  on the filter housing  2 .