Abstract:
An air intake apparatus used for a canister of a fuel system includes a device and system to prevent the accumulation of dust and/or foreign substances from building up in the air filter. An air intake hole, for supplying air to an air filter used for a canister, is positioned in a fuel inlet space.

Description:
CROSS REFERENCE TO RELATED PATENT APPLICATION  
       [0001]     This application claims priority to and the benefit of Korean Patent Application No. 10-2004-0063700 filed in the Korean Intellectual Property Office on Aug. 13, 2004, the entire content of which is incorporated herein by reference.  
       FIELD OF THE INVENTION  
       [0002]     Generally, the present invention relates to an air intake apparatus for an air filter of a canister. More particularly, the present invention relates to an air intake apparatus for the air filter of a canister that can minimize accumulation of dust or foreign substances in the air filter.  
       BACKGROUND OF THE INVENTION  
       [0003]     As is well known in the art, a canister is disposed to a side of a fuel tank such that an inner pressure by a fuel gas generated in the fuel tank can be controlled. In a case that the canister or the like does not exist, the inner pressure of the tank may rise because of the fuel gas, consumption of fuel increases, and air pollution can occur as a result of gas leakage.  
         [0004]     Typically, a filler pipe for supplying fuel to a fuel tank is connected to one side of the fuel tank. A filler neck for accommodating a gasoline pump nozzle to be being inserted therein is formed to an upper end of the filler pipe. One end of the filler neck protrudes into a fuel inlet space formed between a vehicle body and a fuel cap door such that the end of the filler neck is opened/closed by a fuel cap. In addition, the filler neck and the fuel tank are connected by a leveling pipe. The leveling pipe is typically for controlling an amount of fuel delivered to the fuel tank, depending on a pressure of the fuel supplied to the fuel tank during a fuel supplying process.  
         [0005]     An upper portion of the fuel tank and a canister are connected with each other by a fuel evaporation gas line. The fuel evaporation gas generated in the fuel tank flows into the canister through the fuel evaporation gas line. The fuel evaporation gas flows into the canister in a state where an engine stops is captured by activated carbon in the canister. A fuel element in the canister is purged into an intake system of the engine through the purge line by an opening operation of a purge control valve when the engine is operating.  
         [0006]     An end of an air passage is connected to the canister such that the purge operation is more easily done in the canister and another end of the air passage is connected to an air filter located to one side of the filler neck. The air filter is intended to eliminate foreign substances mixed in the air supplied to the canister.  
         [0007]     On the other hand, the air passage and the air filter are also utilized as passages such that an inner pressure of the canister is lowered during a situation where the inner pressure of the fuel tank and the canister is excessively high. However, when a vehicle, having the fuel system as described above, drives in poor road conditions, such as on an unpaved road, the air filter can become plugged because foreign substances, such as dust or dirt, can accumulate in the air filter.  
         [0008]     Also, if the fuel evaporation gas is purged when the air filter is plugged by foreign substances, a pressure developed in the intake system can excessively affect the canister and the fuel tank, thereby potentially causing deformation or cracks of the fuel tank.  
         [0009]     The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention, and therefore, unless explicitly described to the contrary, it should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art that is already known in this country to a person of ordinary skill in the art.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention provides an air intake apparatus having advantages of minimizing accumulation of dust or foreign substance in the air filter. An exemplary air intake apparatus according to an embodiment of the present invention includes an air passage communicating with an air filter for a canister used for a fuel storage device that includes a filler neck installed to a vehicle body, such that one end thereof protrudes into a fuel inlet space formed between the vehicle body and a fuel cap door.  
         [0011]     The filler neck includes an inner pipe defining an fuel supply passage and an outer pipe surrounding at least a portion of the inner pipe such that an air intake space is formed between an outer surface of the inner pipe and the outer pipe. The inner pipe and outer pipe are formed such that the fuel inlet space and the air intake space can communicate with each other. The air filter and the air intake space are in communication with each other by an air supply pipe such that air in the fuel inlet space can flow to the air filter via the air intake space.  
         [0012]     The ends of the inner pipe and the outer pipe are respectively formed to protrude into the fuel inlet space. An end of the outer pipe protrudes into the fuel inlet space a shorter distance than a length of an end of the inner pipe that protrudes into the fuel inlet space, such that the air intake space can communicate with the fuel inlet space in a state that a fuel cap is mounted to the inner pipe. An air intake hole for communicating the fuel inlet space with the air intake space is formed toward the end of the outer pipe that protrudes into the fuel inlet space. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]     The accompanying drawings illustrate exemplary embodiments of the present invention, and, taken together with the description, serve to explain the principles of the present invention, wherein:  
         [0014]      FIG. 1  is a schematic drawing showing an air intake apparatus for supplying air to an air filter of a canister according to an embodiment of the present invention;  
         [0015]      FIG. 2  is a sectional view taken along a line I-I of  FIG. 1  according to an embodiment of the present invention; and  
         [0016]      FIG. 3  is a schematic view showing an air intake apparatus according to another embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0017]     Referring to  FIG. 1 , an air intake apparatus used in a fuel storage device  100  includes a filler neck  30  installed to a vehicle body  15  such that one end thereof protrudes into a fuel inlet space  17  formed between the vehicle body  15  and a fuel cap door  16 . The fuel storage device  100  also includes an air passage  22  in communication with an air filter  23  for a canister  20 . The filler neck  30  includes an inner pipe  31  and an outer pipe  32 .  
         [0018]     The inner pipe  31  defines a fuel supply passage  33 . The outer pipe  32  surrounds at least a portion of the inner pipe  31  such that an air intake space  35  can be formed between an outer surface  50  ( FIG. 2 ) of the inner pipe  31  and the outer pipe  32 . That is, the fuel cap  34  is disposed to an upper end  45  of the inner pipe  31 , and an upper end  46  of the outer pipe  32  is formed to be communicated with the fuel inlet space  17 .  
         [0019]     During fueling of the vehicle, a gasoline pump nozzle for supplying the fuel is inserted into the inner pipe  31 . The inner pipe  31  and outer pipe  32  are formed such that the fuel inlet space  17  and the air intake space  35  are in communication with each other. The air filter  23  and the air intake space  35  are in communication with each other by an air supply pipe  40  such that air in the fuel inlet space  17  can flow to the air filter  23  via the air intake space  35 .  
         [0020]     A lower portion of the outer pipe  32  is fixed on an outer surface  50  of the inner pipe  31 . The air intake space  35  is formed between the inner pipe  31  and the outer pipe  32  by a difference between a diameter of the inner pipe  31  and a diameter of the outer pipe  32 , and the air intake space  35  is communicated with the fuel inlet space  17 . In addition, the upper ends  45  and  46  are respectively formed to protrude into the fuel inlet space  17 .  
         [0021]     Referring to the  FIG. 2 , the diameter of the inner pipe  31  is smaller than the diameter of the outer pipe  32 , and the air intake space  35  is formed between the inner pipe  31  and the outer pipe  32 . In addition, the air supply pipe  40  is connected to the outside of the outer pipe  32 .  
         [0022]     A length of the end  46  of the outer pipe  32  protruding into the fuel inlet space  17  is shorter than a length of the end  45  of the inner pipe  31  protruding into the fuel inlet space  17 , such that the air intake space  35  can communicate with the fuel inlet space  17  when the fuel cap  34  is mounted to the inner pipe  31 . That is, in order to communicate the air intake space  35  with the fuel inlet space  17 , the end  46  of the outer pipe  32  is formed to have a lower height than the end  45  of the inner pipe  31 . Therefore, in spite of the fuel cap  34  closing the inner pipe  31 , air can flow into the air intake space  35 .  
         [0023]     As shown in  FIG. 3 , according to another embodiment of the present invention, an air intake hole  36  can be formed toward the end  46  of the outer pipe  32  that protrudes into the fuel inlet space  17 , such that the fuel inlet space  17  is communicated with the air Intake space  35 . An upper portion of the air supply pipe  40  is communicated with the air intake space  35 , and a lower portion of the air supply pipe  40  is communicated with an intake side of the air filter  23 .  
         [0024]     In consideration of a layout of the fuel inlet space  17 , the air supply pipe  40  may be located only inside of the vehicle body  15 . The fuel inlet space  17  is formed to be able to be opened or closed by a fuel cap door  16  as in a prior art. Because the fuel inlet space  17  is partially isolated from the outside of a vehicle body  15  by the vehicle body  15  and fuel cap door  16 , air that is more pure than air outside of the vehicle body  15  flows into the air intake space  35 . The air that flows into the air intake space  35  is supplied to the air filter  23  through the air supply pipe  40 , and then the air is purified in the air filter  23  and supplied to the canister  20 .  
         [0025]     On the other hand, when the fuel is supplied, the fuel supplier opens the fuel cap door  16 , removes the fuel cap  34 , and then inserts a gas pump nozzle into the inner pipe  31  and supplies the fuel. As the fuel is being supplied into the inner pipe it flows into the fuel tank  10  through a filler tube  33 . At that time, because the inner pipe  31  is separated from the outer pipe  32 , the fuel cannot flow into the air intake space  35 .  
         [0026]     As described, according to an embodiment of the present invention, because air in the fuel inlet space is partially isolated from the outside, by the vehicle body and the fuel cap door, first flows into the air intake space and then into the air filter through the air supply pipe, air that is more pure than air outside of the vehicle body flows into the canister. Thus, a case where the air filter becomes plugged by foreign substances can be reduced.  
         [0027]     While this invention has been described in connection with what is presently considered to be the best practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.