Patent Publication Number: US-2006005817-A1

Title: Fuel fume gas trap device and air intake system including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      This application claims priority of Korean Application No. 10-2004-0052424, filed on Jul. 6, 2004, the disclosure of which is incorporated herein by reference.  
     FIELD OF THE INVENTION  
      Generally, the present invention relates to a fuel fume trap device and an air intake system including the same. More particularly, the present invention relates to a fuel fume trap device and an air intake system including the same for preventing emission of fuel fumes (evaporation fuel in gaseous form).  
     BACKGROUND OF THE INVENTION  
      Generally, fuel fumes are mainly composed of hydrocarbon (HC) and may be a factor contributing to pollution if the fumes are emitted to the atmosphere. Therefore, for preventing the emission of fuel fumes, a conventional canister and a purge control solenoid valve for controlling the canister are mounted between a fuel tank and an air intake system. According to such a scheme, the emission of the fuel fumes is effectively prevented during an engine operation.  
      However, while the engine is stopped, the fuel fumes in the engine flow reversely through an air intake system and a fuel system and are emitted to the atmosphere. Therefore, for minimizing the emission of fuel fumes through the air intake system and the fuel system while the engine is stopped, a trap including a carbon material for filtering the fuel evaporation gas may be mounted in an intake air passage.  
      In the case that the trap is mounted in an intake air passage, although the emission of the fuel fumes may be effectively prevented while the engine is stopped, the engine performance may still be reduced because flow of the intake air experiences resistance while passing through the intake air passage during engine operation. In addition, in the case that carbon material breaks off, the engine may be damaged by the broken carbon materials flowing into the engine.  
      The information disclosed in this Background of the Invention section is only for enhancement of understanding of the background of the invention and 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  
      The motivation for the present invention is to provide a fuel fume trap device and an air intake system including the same having non-limiting advantages of preventing emission of fuel fumes. An exemplary fuel fume trap device and an air intake system including the same according to an embodiment of the present invention includes: an air duct; an air cleaner connected to a downstream side of the air duct for purifying intake air; and a fuel fume trap device for blocking reverse flowing of fuel fumes through an intake air passage connected to a downstream side of the air cleaner, wherein the fuel fume trap device comprises a fuel fume trap mounted in the intake air passage so as to selectively open and close the intake air passage and an actuator for actuating the fuel fume trap.  
      In a further embodiment, the actuator actuates the fuel fume trap so as to open the intake air passage during engine operation, and actuates the fuel fume trap so as to close the intake air passage when the engine is stopped.  
      In another further embodiment, the actuator actuates the fuel fume trap on the basis of signals transmitted from an engine control unit or an ignition switch.  
      In a further embodiment, a fuel fume trap device for blocking reverse flowing of fuel fume through an intake air passage of an engine comprises a fuel fume trap mounted in the intake air passage so as to selectively open and close the intake air passage and an actuator for actuating the fuel fume trap.  
      In another further embodiment, the actuator actuates the fuel fume trap so as to open during engine operation, and actuates the fuel fume trap so as to close the intake air passage when the engine is stopped.  
      In another further embodiment, the actuator actuates the fuel fume trap on the basis of signals transmitted from an engine control unit or an ignition switch.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The accompanying drawings illustrate exemplary embodiments of the present invention, and, together with the description, serve to explain the principles of the present invention, wherein:  
       FIG. 1  shows an intake system according to an embodiment of the present invention; and  
       FIG. 2  shows a fuel evaporation gas trap device according to an embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
      An embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings.  
       FIG. 1  is a drawing showing an intake system according to an embodiment of the present invention. As shown in  FIG. 1 , an intake system according to an embodiment of the present invention includes: an air duct  117 ; an air cleaner  115 ; and a fuel fumes gas trap device  113 . The air cleaner  115  is connected to a downstream side of the air duct  117  and purifies intake air.  
      An intake air passage  107  is connected to a downstream side of the air cleaner  115  and the fuel evaporation gas trap device  113  is mounted between the air cleaner  115  and the intake air passage  107 . Therefore, the fuel evaporation trap device  113  prevents reverse flow of the fuel evaporation gas through the intake air passage  107 . As shown in  FIG. 1 , the air that has been introduced into an intake hole  111  passes the air duct  117 , is then purified at the air cleaner  115  that is connected to a downstream side of the air duct  117 .  
      The air purified at the air cleaner  115  is supplied to an engine  101  by sequentially passing through the fuel fume gas trap device  1   13 , the intake air passage  107 , a throttle valve  105 , and a plenum  103  (refer to the solid line arrows in  FIG. 1 ).  
      In addition, the intake air is mixed with fuel injected from a fuel injector (not shown) mounted in the intake air passage  107  and then the intake air is supplied to the engine  101 . The fuel fumes may be formed by fuel remaining in a combustion chamber or a crankcase evaporating.  
      While the engine is stopped, the fuel fumes tend to be emitted to the atmosphere by flowing reversely from the engine  101  or a positive crankcase ventilation (PCV) hose and passing through the intake air passage  107  in a direction reverse with the direction through which the intake air passes (refer to the dotted line arrows in  FIG. 1 ). At that time, the fuel fume gas trap device  113  blocks an emission of the fuel evaporation gas to the atmosphere by a reverse flow through the intake air passage  107 .  
       FIG. 2  shows a fuel evaporation gas trap device according to an embodiment of the present invention. As shown in  FIG. 2 , the fuel fume trap device  113  includes an actuator  121  and a fuel fume trap  123 . For example, the actuator  121  can be realized as a motor.  
      The fuel evaporation trap  123  is mounted to the intake air passage  107  such that the fuel evaporation trap  123  can selectively open or close the intake air passage  107  and the actuator  121  actuates the fuel evaporation trap  123 . The actuator  121  includes a drive gear  125 . The fuel evaporation gas trap  123  is connected to a driven gear  127  geared with the drive gear  125 . Therefore, the drive gear  125  and the driven gear  127  are actuated by an actuation of the actuator  121  and the fuel fume trap  123  can rotate along the direction of the arrows in  FIG. 2 .  
      A solid line of the fuel fume trap  123  illustrates a state that the fuel evaporation gas trap  123  closes the intake air passage  107  and a dotted line of the fuel fume trap  123  illustrates another state in which the fuel fume trap  123  opens the intake air passage  107 . That is, the intake air passage  107  is selectively opened or closed by the rotation of the fuel fume trap  123  by the actuator  121 .  
      The fuel fume trap  123  is exemplarily mounted in the intake air passage  107 , however, it may be mounted in another place of the air intake system e.g., the air duct. The actuator  121  can actuate the fuel fume trap  123  on the basis of signals transmitted from any control unit of a vehicle.  
      According to an embodiment of the present invention, the actuator  121  actuates the fuel fume trap  123  on the basis of signals transmitted from an engine control unit (ECU)  200 . On the other hand, the actuator  121  may also actuate the fuel fume trap  123  on the basis of signals transmitted from an ignition switch  200 . That is, in the case of the engine operation, the actuator  121  actuates the fuel fume trap  123  so as to open the intake air passage  107 , on the basis of signals transmitted from the ECU  200 .  
      In addition, when the engine stops, the actuator  121  actuates the fuel fume trap  123  so as to close the intake air passage  107 .  
      When the engine  101  stops, if the fuel fume trap  123  closes the intake air passage  107 , the emission of the fuel fume to the atmosphere can be prevented.  
      On the other hand, at the time when the engine  101  starts, if the fuel fume trap  123  opens the intake air passage  107 , the engine effectively operates because the fuel fume trap  123  does not produce resistance to an air flow.  
      The engine control unit (ECU)  200  may include one or more processors activated by a predetermined program, and the predetermined program can be programmed to include a set of instructions for enabling the actuator  121  to perform the above described operations according to an embodiment of this invention.  
      According to an embodiment of the present invention the fuel fume trap can prevent the fuel fumes from flowing in reverse from the engine without causing resistance to the intake air introduced into the engine. In addition, damage caused by a breakdown of a carbon material in the fuel fume trap can be prevented.  
      In addition, manufacturing costs can be reduced because the fuel fume trap can be manufactured for less than prior devices. Furthermore, air pollution can be prevented because the fuel fumes are more effectively prevented from escaping into the atmosphere.  
      While this invention has been described in connection with what is presently considered to be the most 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.