Patent Publication Number: US-2011056383-A1

Title: Filter

Description:
The invention relates to a filter with the features of the introductory part of Claim  1 . The object of the invention is to devise a filter that can be located on vehicles and that, especially while the vehicle is moving, is able to effectively filter dust, especially fine dust, from the air. 
     This object is achieved according to the invention with a filter that has the features of Claim 
     Preferred and advantageous configurations of the filter according to the invention are the subject matter of the dependent claims. 
     Since the filter according to the invention ensures not only several filter layers, but also effective protection against the entry of water into the filter, it is easily possible, and especially without adversely affecting the efficiency and operation of the filter, to mount it on vehicles. 
     All vehicles can be considered, regardless of whether they are ground vehicles, such as road vehicles and rail cars, aircraft or watercraft. 
     It is preferable if the filter according to the invention is located on the front surface or in the region of the front surface of a vehicle. 
     Within the framework of the invention, it is also possible to supply the air flow that is used to cool the drive motor to the input side of the filter according to the invention before or after passage through the radiator of the drive motor. 
     The arrangement of the filter according to the invention above the front window or windshield of vehicles is quite especially preferred. In this arrangement, the entry-side boundary wall of the filter that therefore points forward can be arranged slanted in the manner of a spoiler. 
     Installation of the filter on the bottom of a vehicle, e.g., with the entry opening lying in the region of the bumper, is also considered. 
     Since, in the filter according to the invention, there are boundary walls on its front and its rear (the end surface of the filter pointing forward relative to the direction of travel and the end surface of the filter pointing backward relative to the direction of travel), which walls are made and set up to allow the entry or exit of air, but also to prevent the entry of water into the filter as far as the filter layers, the effective result is that the filter layers of the filter do not become wet and their filter action, especially when fine dust is being filtered out, is not adversely affected. 
     In one preferred embodiment of the filter according to the invention, between the filter layers of the internals, there are free spaces that make it possible for dust that has passed through the filter layers anyway to collect and settle there, optionally with the formation of a fine dust cake, and if the dust was moist, it is dried there so that filtering is enhanced. 
     The perforated walls on the end surfaces of the filter that prevent the entry of water are, for example, rib meshes with parts that are aligned obliquely to their surface extension and/or perforated sheets with guide surfaces that are attached to them, especially pointing to the inside, and that are tilted to the surface extension of the wall. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the entry-side boundary wall, e.g., a perforated plate or rib mesh, bears slanted guide surfaces on its side facing the interior of the filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that there are guide surfaces with different lengths, specifically shorter guide surfaces and longer guide surfaces. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the guide surfaces are aligned rising obliquely upward relative to the direction of air flow through the filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that there is a wall with holes and guide surfaces, e.g., a perforated plate, following the preliminary filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the guide surfaces are aligned pointing obliquely downward relative to the direction of air flow through the filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that upstream from the first filter layer, there is a carrier with flaps that are pivotally mounted on it. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that between the carrier and the wall, downstream from the preliminary filter there is a channel for draining the water that has entered the filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that a moisture sensor is assigned to the channel. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the flaps on the carrier are controlled in their action by the moisture filter such that the flaps are closed when the moisture sensor detects moisture in the channel. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the preliminary filter is a washable organic or mineral fiber. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the filter layer that is located preferably following the flaps is a coarse dust filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that there are two fine dust filters in succession. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that there is a free space between the first fine dust filter and the coarse dust filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that there is a free space between the fine dust filters. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that there are guide surfaces projecting to the outside from the outflow-side boundary wall. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the guide surfaces of the outflow-side boundary wall, e.g., of the perforated sheet, are aligned descending obliquely downward relative to the flow direction of the air through the filter. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the free ends of the guide surfaces are angled downward on the outflow-side perforated sheet. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the individual components of the filter are self-supporting components that are inserted and can be removed individually in a housing. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the first fine dust filter is a filter of class F5. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that the second fine dust filter is a filter of class F6. 
     In one possible embodiment that is considered within the framework of the invention, the filter according to the invention is characterized in that there is a free space between the fine dust filter and the boundary wall that is located on the exit side. 
     The invention also relates to a vehicle with the features of Claim  15 , the entry-side boundary wall of the filter being located in the region of an air flow that forms when the vehicle is moving. 
     In one possible embodiment that is considered within the framework of the invention, the vehicle according to the invention is characterized in that the entry-side boundary wall of the filter is aligned essentially perpendicular to the lengthwise extension of the vehicle. 
     In one possible embodiment that is considered within the framework of the invention, the vehicle according to the invention is characterized in that the filter with its entry-side boundary wall is located above the passenger compartment of a vehicle, especially in the region above the windshield. Arrangements of the filter laterally next to or under the passenger compartment are likewise considered within the framework of the invention. 
     In one possible embodiment that is considered within the framework of the invention, the vehicle according to the invention is characterized in that in trucks, the filter is located aligned rising obliquely upward from the top edge of the windshield. 
     In one possible embodiment that is considered within the framework of the invention, the vehicle according to the invention is characterized in that the entry-side boundary wall is aligned obliquely to the lengthwise extension of the vehicle. 
     Other details, features and advantages of the filter according to the invention and its use on vehicles will become apparent using the following description of one preferred embodiment. 
    
    
     
       Here: 
         FIG. 1  schematically shows the fundamental structure of a filter in one example, 
         FIG. 2  shows a modified embodiment, 
         FIG. 3  schematically shows a first installation example of a filter according to the invention, 
         FIG. 4  schematically shows another installation example of the filter according to the invention, and 
         FIG. 5  schematically shows another embodiment of a filter according to the invention. 
     
    
    
     In the embodiment shown in  FIG. 1 , the filter according to the invention has the structure described below. The individual parts of the filter are mentioned and described in the sequence, which corresponds to the direction of flow of the air to be filtered through the filter: 
     On the entry side, the wall that forms the end surface is a perforated sheet  1  or a rib mesh, consisting of a material that is resistant to corrosive rain, salt water, etc. On the inside of the perforated sheet  1  in the flow direction of the air (arrow  3 ), there are guide surfaces  5 ,  7  that point obliquely upward. There are longer guide surfaces  5  and shorter guide surfaces  7  here. When the filter is located above the windshield of a vehicle, the front boundary wall can be tilted in the manner of a “spoiler,” as is shown in  FIG. 2 . 
     The guide surfaces  5 ,  7  route the air flow into a first preliminary filter  9 . The preliminary filter  9  consists of a washable filter material, especially a filter material that consists of plastic or mineral substance in fiber form. Here, water entering through the entry-side perforated sheet  1  can be used to clean the preliminary filter  9  by washing it out. 
     The guide surfaces  5 ,  7  on the inside of the perforated sheet  1  improve drying of the preliminary filter  9  after it has been washed out. 
     Following the preliminary filter  9 , on its inside, there is another perforated sheet  11  with guide surfaces  13  or a rib mesh, the guide surfaces  13  viewed in the flow direction (arrow  9 ) being aligned running obliquely downward, therefore opposite the slanted position of the guide surfaces  5  and  7 . In this way, water that is passing through the preliminary filter  9  is diverted downward and emerges again through an angled lower channel  15  along the bottom of the filter housing on the bottom end  17  out of the filter arrangement forward ( FIG. 1 ) or preferably to the rear ( FIG. 2 ). Thus, it is ensured that water cannot travel into the components of the filter according to the invention that are formed following the arrangement consisting of the perforated sheet  1 , preliminary filter  9  and perforated sheet  11 . In the region of the channel  15 , there is a rain sensor  19  (moisture sensor) that controls flaps  21  that are arranged downstream from the second perforated sheet  11  and that closes them when an especially large amount of water passes through the preliminary filter  9 , e.g., when driving through a car wash. These flaps  21  are closed by a motor in the case of starting so that water cannot penetrate further into the interior of the filter. 
     There is a coarse dust filter  23  downstream from the arrangement with the flaps  21 . The coarse dust filter  23  consists of the same material as the first preliminary filter  9 , but is preferably made denser (smaller free passage cross-sectional area) than the preliminary filter  9 . 
     Following the coarse dust filter  23 , there is a free space  25  in which dust, especially fine dust, can settle. 
     Following the free space  25 , there is a first fine dust filter  27 . This fine dust filter  27  filters fine dust with an order of magnitude of roughly 10 μm from the air that is flowing through the filter. The fine dust filter  27  can be a filter (F5, DIN 779) that contains a filter pack of folded (pleated) microfiber paper with plastic spacer filaments (fold pack). For example, a filter from Euro Filter GmbH (Dortmund, FRG) of filter class EN 1822 and of design/type H13 or H14 is suitable. 
     Following the fine dust filter  27 , there is another free space  29 . In the free spaces  25  and  29 , not only is settling of (fine) dust particles possible, but the (fine) dust particles are dried. 
     Following the second free space  29 , there is another fine dust filter  31  for filtering fine dust particles with a size of less than, for example, 1 μm. This fine dust filter  31  can be a filter of filter class F6 from Euro Filter GmbH (Dortmund, FRG). 
     The filter layers of the fine dust filter can be located between support gratings. 
     There is another free space  32  downstream from the fine dust filter  31 . 
     Following the free space  32  downstream from the second fine dust filter  31 , there is a wall that forms the back end surface and that, for example, is a perforated sheet  33  similar to the perforated sheet  11  downstream from the first preliminary filter  9  with guide surfaces  35  that are slanted downward to the rear. This prevents entry of rain water from the back of the filter. 
     In the perforated sheet  33  with guide surfaces  35 , the guide surfaces  35  are made larger and are optionally angled downward in order to ensure that water cannot enter the filter from the rear. 
     The indicated components (perforated sheet  1 , preliminary filter  9 , perforated sheet  11 , carrier  20  for the flaps  21 , (coarse dust) filter  23 , (fine dust) filter  27 , (fine dust) filter  31  and perforated sheet  33  are preferably self-supporting components (“cassettes”) that can be inserted into a housing that surrounds the filter. Thus, it is possible to replace individual parts of the filter. 
     The filter according to the invention is especially designed to be mounted on vehicles on their front, especially in the region above the windshield. The filter according to the invention can be integrated above the passenger compartment of a vehicle, especially a truck, for example into a spoiler provided there. In this case, above the entry opening into the filter, headlights or blinkers can be additionally mounted. 
     It is possible to arrange the entry opening of the filter in the region above the front bumper of a vehicle. 
     All locations on vehicles in which a relative wind is acting are conceivable here. One installation example is shown by  FIG. 3 . In this example, a filter  50  of the invention that, for example, has the structure described using  FIG. 1  or  FIG. 2  is mounted above the passenger compartment  52 , therefore above the windshield  54 , so that the relative wind (arrow  56 ) enters the filter  50  via the perforated sheet  1  and emerges again from the filter  50  with the dust removed through the perforated sheet  33  (arrow  58 ). 
     The installation example from  FIG. 4  shows how a filter according to the invention can also be arranged in the region of the bottom of a vehicle such that the entry-side front wall (perforated sheet  1 ) is located in the region of the front bumper. 
     The embodiment of a filter according to the invention that is shown in  FIG. 5  has the structure described below. 
     On the entry side, the wall that forms an end surface is a perforated sheet  1  or a rib mesh that consists of a material that is resistant to corrosive rain, salt water, etc. On the inside of the perforated sheet  1  in the flow direction of the air (arrow  3 ), there are guide surfaces  7  that point obliquely upward. 
     When the filter is located above the windshield of a vehicle, the front boundary wall can be slanted in the manner of a spoiler, as is shown in, for example,  FIG. 2 . 
     The guide surfaces  7  route the air flow to a layer of metal nonwoven floss, especially steel nonwoven floss  8 , water that collects in the space between the perforated sheet  1  and the layer  8  of steel nonwoven floss flowing downward to a channel  18  that is provided in the lower boundary wall of the filter. Water entering the channel  18  flows to the filter end that is the back end relative to the direction of travel (to the right in  FIG. 5 ). 
     Following the layer  8  of steel nonwoven floss, there is a layer  10  that is used as a coarse dust filter and that is formed from a waterproof filter material. Water arising in the coarse dust filter  10  also flows downward into the channel  18 . 
     There is again a rib mesh  11  similar to the rib mesh  1  on the side (back side) of the layer  10  that is used as the coarse dust filter, which side is facing away relative to the flow direction (arrow  3 ). Following the rib mesh  11 , there is a free space  25  that adjoins, always relative to the flow direction, a first fine dust filter  27  that is located between the support gratings  28  and likewise consists of waterproof filter material. Downstream from the fine dust filter  27 , there is another free space  29  followed by a second fine dust filter  31  that is inserted in a frame. 
     At a distance from the fine dust filter  31 , there is another free space  34  and then a back wall  33  in the form of a perforated sheet, for example similar to the perforated sheet  11 , or in the form of a support grating as the wall that forms the back end surface of the filter. In the space  34 , in one embodiment there can be at least one motorized fan  36  that also produces the air flow necessary for the effectiveness of the filter, when the vehicle in which the filter is installed is stopped or only driving slowly. 
     In summary, one embodiment of the invention can be described as follows: A filter  50  that can be located on vehicles in the region of the relative wind has an inlet-side perforated sheet with slanted guide surfaces  5 ,  7 , a preliminary filter  9 , a coarse dust filter  23 , a first fine dust filter  27  with a free space  25  between the coarse dust filter  23  and the fine dust filter  27 , a second fine dust filter  31  with a free space  29  between the fine dust filters  27 ,  31 , and, on the air exit side, another perforated sheet  33  with slanted guide surfaces  35 . With this filter, when vehicles, especially motor vehicles, are traveling on roads, there is effective filtering of dust, especially also fine dust, from the air that is flowing under the action of the relative wind through the filter  50 .