Abstract:
An air cleaner of an internal combustion engine has a housing with a slide-in opening and receives a slide-in filter element through this opening. A cover element closes off the slide-in opening. The cover element has a snap element for fixing the cover element at the housing. The cover element has a contact face defining a first main plane. A sealing is disposed between the filter element and the housing and seals between filter element and housing. A sealing face provided at the housing interacts with the sealing and defines a second main plane. The housing has a contact face abutting the contact face of the cover element in the closing state of the cover element. An angle between the second main plane of the sealing face of the housing and the first main plane of the contact face of the cover element is different from 90°.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of international application No. PCT/EP2013/059570 having an international filing date of 8 May 2013 and designating the United States, the international application claiming a priority date of 9 Jul. 2012, based on prior filed European patent application No. 12 290 229.9, the entire contents of the aforesaid international application and the aforesaid European patent application being incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to an air cleaner in particular of an internal combustion engine in particular of a motor vehicle, comprising a housing with a slide-in opening for inserting a slide-in filter element, a cover element for closing the slide-in opening, which comprises at least one one-piece snap element for fixing the cover element at the housing. 
     DE 10 2007 063 252 A1 discloses a slide-in air filter of an air conditioner of a vehicle. The air conditioner comprises an air blower for sucking in fresh ambient air or recirculating air from the vehicle interior. The air conditioner further comprises an air duct on the inlet side for the air in front of the air blower, which has a holding fixture for the slide-in air filter. The slide-in air filter comprises a slot and an air filter. The slot with the air filter is bendable around a bending axis. The bending axis is aligned parallel to a plane of insertion and at right angles to a direction of insertion. 
     It is an object of the invention to provide an air cleaner of the above-mentioned kind, which is capable of establishing an effective seal to impede a leakage of air in the air cleaner. Further, it should be easy to open and close the cover element. 
     SUMMARY OF THE INVENTION 
     The object is achieved in that an angle between a main plane of a sealing face of the housing for a sealing between the filter element and the housing and a main plane of a contact face of the cover element, at which a corresponding contact face of the housing abuts in a closing state of the cover element, is different from 90°. 
     Favorably, the main planes of the sealing face and the contact face are not perpendicular. So, a component of a force realized by the at least one snap element for pressing the cover element against the housing also can realize a pressure of the filter element against the sealing face. In this way, the tightness of the sealing between the filter element in the housing and the tightness of the connection of the cover element and the housing both are improved. The main planes define the average orientation of the according faces each. This means that the faces themselves can have areas which extend in an angle to the according main plane. In particular, the faces can have a profiling along the main plane. The at least one snap element is realized in one piece with the cover element and so is loss-proof connected to the cover element. This simplifies an opening and closing process of the cover element. Further, separate snap elements, in particular screws or tension springs, are not necessary. Favorably, the at least one snap element can be easily realized in one production step together with the cover element. Advantageously, the cover element and the at least one snap element are made of plastic. With plastic, elastic snap elements can be realized easily. The cover element with the at least one snap element also can be made of a material different from plastic. 
     According to a favorable embodiment of the invention, a tension force of the at least one snap element can realize a first force component, which is perpendicular to the main plane of the contact face of the cover element, and a second force component, which is perpendicular to the main plane of the sealing face of the housing. Advantageously, the tension force of the at least one snap element can be perpendicular to the main plane of the sealing face so that the second force component is identical with the tension force itself. The first force component can effect the pressure of the cover element against the housing so that the tightness of the connection between the cover element and the housing can be improved. The second force component can cause the pressure of the filter element against the sealing face of the housing so that the compression of the sealing between the filter element and the housing and thus the tightness can be improved. 
     Advantageously, an angle between a direction of a tension force of the at least one snap element and the main plane of the contact face of the cover element can be different from 90°, in particular the angle can be between 20° and 70°, preferably approximately 45°. Experiments have shown that at an angle between 20° and 70°, preferably approximately 45°, the effect of the tension force can improve the gas tightness of the contact area between the filter element and the sealing face as well as the gas tightness of the contact area between the cover element and the housing. 
     Favorably, an angle between a direction of a tension force of the at least one snap element and the main plane of the sealing face of the housing for the sealing between the filter element and the housing can be approximately 90°. So, a pressure for compressing the sealing and improving the sealing function between the filter element and the housing can be maximized. 
     According to a further favorable embodiment of the invention, a sealing element can be arranged between the contact face of the housing and the cover element. Advantageously, the sealing element can be flexible. Preferably, the sealing element can be made of an elastomer. With the sealing element, tolerances of the shape of the according contact faces of the cover element and the housing and/or the position of the cover element relative to the housing can be compensated. Further, the sealing function can be increased. Additionally, the sealing element can effect an acoustical decoupling of the cover element and the housing. Advantageously, the sealing element and the cover element can be realized as a two-component part. So, the sealing element can be loss-proof attached to the cover element. Additionally, the opening and closing of the cover element can be further simplified. 
     Advantageously, the slide-in opening can be arranged on a raw-gas side of the filter element. So, a suction of leak air into the housing through the slide-in opening to the clean-air side of the filter element can be impeded. 
     According to a further favorable embodiment of the invention, the cover element can be part of a drawer in which the slide-in filter element can be placed and which can be slid through the slide-in opening into the housing. The filter element can be placed easily and stably in the drawer. The drawer together with the filter element can be slid into the housing and placed precisely in its end position. So, even a filter element whose internal strength is not sufficient for pushing it on its own can be placed precisely and stably in the housing. Favorably, the drawer can have a frame for holding the filter element. The drawer can be permeable to gas at least in direction of the air flow through the filter element. 
     Favorably, at least one snap face, which can act as a counterpart for the at least one snap element, can be arranged at the housing. With this snap face, the tension force of the snap element can be transferred to the housing. 
     Further, at least one counter support for connecting the housing and the cover element can be arranged on an opposite side of the at least one snap face and the at least one snap element. In this way, the cover element can be clamped between the counter support and the at least one snap element. So the cover element can be pressed against the housing on opposite sides. Thus, the pressure of the cover element against the housing can be distributed all over the contact face. So, the tightness of the sealing further can be improved. 
     Advantageously, the at least one snap element can have at least one unlocking element for unlocking the fixation of the cover element at the housing. With the at least one unlocking element, the at least one snap element easily can be unlocked so that the cover element easily can be opened in particular for removing the filter element. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention together with the above-mentioned and other objects and advantages may best be understood from the following detailed description of the embodiments, without being restricted to the embodiments. 
         FIG. 1  is a first perspective view of an air cleaner of an internal combustion engine of a motor vehicle with a housing in which a drawer with a slide-in filter element is placed. 
         FIG. 2  is a second perspective view of the air cleaner of  FIG. 1 . 
         FIG. 3  is a cross-section of the air cleaner of  FIG. 2  along the section line III-III of  FIG. 2 . 
         FIG. 4  is an enlarged view of the cross-section of the air cleaner of  FIG. 3  of an area of a snap element for fixing a cover element of the drawer at the housing. 
         FIG. 5  is a third perspective view of the air cleaner of  FIGS. 1 to 4  wherein the snap elements are shown in an unlocked state. 
         FIG. 6  is a perspective view of the air cleaner of  FIG. 5  with the unlocked snap elements, with the view angle of  FIG. 2 . 
         FIG. 7  is a cross-section of the air cleaner of  FIG. 6  along a section line VII-VII of  FIG. 6 . 
         FIG. 8  is an enlarged view of the cross-section of the air cleaner of  FIG. 7  of the area of the unlocked snap element. 
     
    
    
     In the drawings, same or similar elements are referred to by same reference numerals. The drawings are merely schematic representations, not intended to portray specific parameters of the invention. Moreover, the drawings are intended to depict only typical embodiments of the invention and therefore should not be considered as limiting the scope of the invention. 
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In  FIGS. 1 to 8 , an air cleaner  10  of an internal combustion engine of a motor vehicle is depicted. 
     The air cleaner  10  has a housing  12  which comprises of an upper housing part  14 , a lower housing part  16 , and an inlet housing part  18 . The upper housing part  14  is fixed at the lower housing part  16 , for example, by welding. On the opposite side of the upper housing part  14 , the inlet housing part  18  is fixed at the lower housing part  16 , for example, by welding. 
     The inlet housing part  18  has an inlet  20  for ambient air which has to be cleaned. The upper housing part  14  has an outlet  22  for the cleaned air. The lower housing part  16  has an air duct  24 , which is shown in  FIGS. 3 and 7 , with a holding fixture  26  for a drawer  28 . In the drawer  28 , a slide-in filter element  30  is placed. The lower housing part  16  has a slide-in opening  32  for inserting the drawer  28  with the filter element  30  into the holding fixture  26 . 
     An inlet chamber  34  of the lower housing part  16  is connected by an opening  38  with an outlet chamber  36  of the upper housing part  14 . The filter element  30  is covering the opening  38  and so separates the inlet chamber  34  from the outlet chamber  36 . The inlet  20  leads into the inlet chamber  34 . The outlet  22  comes from the outlet chamber  36 . The inlet chamber  34  and the slide-in opening  32  are on a raw-gas side  40  of the filter element  30 . The outlet chamber  36  and the opening  38  are on a clean-gas side  42  of the filter element  30 . 
     The filter element  30  has a pleated filter medium  44  which has an approximately cuboid shape. A circumferential elastic sealing  48  is fixed tight at an edge of the filter medium  44 . The sealing  48  is faced toward a sealing face  46  of the housing part  14 . In a locked state of the drawer  28 , which is shown in  FIGS. 1 to 4 , the sealing  48  abuts gas-tightly against the sealing face  46 . The sealing face  46  is surrounding the opening  38 . The sealing  48  preferably can be made of polyurethane foam. The sealing face  46  has a main plane depicted in  FIGS. 3 and 5  in broken line  50 . The main plane  50  defines a main orientation of the sealing face  46 . Preferably, the sealing face  46  is flat. 
     The slide-in opening  32  is surrounded by a contact face  52 . The contact face  52  has a main plane is depicted in broken line  54  in  FIGS. 3 and 4 . The main plane  54  defines a main orientation of the contact face  52 . Preferably, the contact face  52  is flat. 
     The drawer  28  is made of plastic. It has a frame  56  for holding the filter element  30 . In flow direction of the air, the frame  56  is permeable to gas. The flow direction of the air is indicated in  FIG. 3  with an arrow  57 . Further the drawer  28  has a cover element  58 , which is arranged in one piece with the frame  56 . The cover element  58  has approximately the shape of a hollow cuboid, which is halved along one of its space diagonals. At its open edge, it has an elastomeric sealing element  60 , which is realized as a two component part with the cover element  58 . The face of the sealing element  60  realizes a contact face  62  of the cover element  58 . 
     In a locked state of the drawer  28 , the cover element  58  closes tightly the slide-in opening  32  of the lower housing part  16 . The contact face  62  of the sealing element  60  abuts tightly on the contact face  52 , which surrounds the slide-in opening  32 . In the locked state, a main plane of the contact face  62  extends more or less along the main plane  54  of the contact face  52 . For reason of clarity, in  FIGS. 3 and 4  the main plane of the contact face  62  is indicated by the same broken line and has the same reference number as the main plane  54 . 
     An angle  64  between the main plane  50  of the sealing face  46  and the main plane  54  of the contact face  62  of the cover element  58  is different from 90°. For example, the angle  64  is between 20° and 70°, preferably about 45°. 
     The cover element  58  comprises two snap elements  66  for fixing the cover element  58  at the housing  12 . The snap elements  66  are realized in one piece each with a common plate  68 . The common plate  68  is realized in one piece with the outer surface of the cover element  58 . The common plate  68  with the snap elements  66  is flexibly pivoted at the cover element  68 . Each snap element  66  has a snap tab  70  which extend in the locked state of the drawer  28  parallel to the main plane  50  of the sealing face  46 . 
     A snap face  72  which acts as a counterpart for the snap elements  66  is connected to the upper housing part  14 . The snap face  72  extends parallel to the main plane  50  of the sealing face  46 . In the locked state of the drawer  28 , the snap face  72  passes through a gap  74  between the snap elements  66  and an upper edge of the cover element  58 . 
     The snap elements  66  each have an unlocking element  76  for unlocking the fixation of the cover element  58  at the housing  12 . 
     A counter support  78  for connecting the lower housing part  16  and the cover element  58  is arranged on an opposite side of the snap face  72  and the snap elements  66 . The counter support  78  comprises a support element on the side of the lower housing part  16  and a corresponding support element on the side of the cover element  58 . 
     In the locked state of the drawer  28 , a tension force  80  of the snap elements  66  each cause a first force component  82  which is perpendicular to the main plane  54  of the contact face  62  of the cover element  58 . The tension forces  80  of the snap elements  66  themselves are perpendicular to the main plane  50  of the sealing face  46  of the housing  12  and so realize a second force component each. The angles between the tension forces  80  and the main plane  50  are indicated with the reference numeral  86 . 
     An angle  84  between the direction of the tension force  80  of the snap elements  66  each and the main plane  54  of the contact face  52  of the cover element  58  are different from 90°. The angles  84  favorably are between 20° and 70°, preferably approximately 45°. 
     For replacing the filter element  30 , the unlocking elements  76  are pulled away from the upper housing part  14 . So, the snap tabs  70  are separated from the snap faces  72  each. The snap faces  72  get out of the gaps  74 . This situation is shown in  FIGS. 5 to 8 . The drawer  28  with the filter element  30  is pivoting away from the sealing face  46  so that the sealing  48  can relax. A bar  88  for positioning, which is fixed at the opposite side of the snap face  72 , gets out of an according groove  90  which is arranged in the upper edge of the cover element  68 . The corresponding support elements of the counter support  78  on the side of the housing part  16  and the cover element  58  are separated. The drawer  28  is pulled out of the holding fixture  26  of the lower housing part  16  against a direction  92  of insertion. The filter element  30  is being replaced. 
     For closing, the drawer  28  is pushed in the direction  92  of insertion until the snap tabs  70  reach the snap faces  72 . Then, the drawer  28  is pivoted towards the sealing face  46 . Thereby, a front face  94  of the snap tabs  70 , which are sloped like ramps, each are gliding along the according front faces  96  of the snap faces  72 . The front faces  96  of the snap faces  72  are sloped accordingly. The snap tabs  70  engage the snap faces  72 , the bar  88  for positioning engages the groove  90 , and the support elements of the counter support  78  are combined. The sealing  48  and the sealing element  60  are compressed so that the opening  38  and the slide-in opening  32  are sealed tightly. 
     The invention is not limited to an air cleaner  10  of an internal combustion engine of a motor vehicle. The invention can also be applied to other kinds of air cleaners in particularly for vehicles. The invention can further be applied to other kinds of internal combustion engines, in particular for industrial engines. 
     The angle  86  between the direction of the tension forces  80  of the snap elements  66  each and the main plane  50  also can be different from 90°. 
     Instead of being pleated with an approximately cuboid shape, the filter medium  44  also can be shaped in a different kind. The filter medium  44  can also be flat without pleats. 
     The housing  12  can also have more or fewer than three housing parts  14 ,  16 ,  18 . 
     Instead of welding, the housing parts  14 ,  16 ,  18  can be fixed together in another way, for example by gluing or by use of mechanical fixing parts, for example, screws or springs. 
     Instead of ambient air, also another gas, for example, recirculating air or recirculating exhaust gas can be cleaned by the air cleaner  10 . 
     The sealing  48  can be made of a material different from polyurethane foam. 
     Instead of being flat, the sealing face  46  also can have a profiling or can be sloped relative to the main plane  50 . 
     Instead of being flat, the contact face  52  also can have a profiling or can be sloped relative to the main plane  54 . 
     More or fewer than two snap elements  66  can be used. 
     The cover element  58  can be realized without the sealing element  64 . 
     The slide-in opening  32  also can be arranged on the clean-gas side  42  of the filter element  30 . 
     The drawer  28  also can be made of a material different from plastic. 
     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.