Abstract:
A canister for vehicles provided with an activated carbon to absorb an evaporation gas evaporated from a fuel tank, and releasing the absorbed evaporation gas to an engine, may include a housing to receive the activated carbon; an evaporation gas supply passage formed to the housing and fluid-connected to the fuel tank; an air passage formed to the housing and selectively receiving an air from the exterior of the housing; and a purge passage formed to the housing and fluid-connected to a purge line to supply the evaporation gas to the engine according to a flow of the received air, wherein the purge passage is provided with a first purge passage formed to the housing and directly fluid-connecting the housing to the purge line and a second purge passage formed to the housing and having an end portion positioned inside the first purge passage or the purge line.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority to Korean Patent Application No. 10-2010-0094724 filed in the Korean Intellectual Property Office on Sep. 29, 2010, the entire contents of which is incorporated herein for all purposes by this reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a canister for vehicles and a fuel supply system provided with the same, and more particularly to a canister for vehicles and a fuel supply system provided with the same mounted at a hybrid vehicle and increasing purge of an evaporation gas purge. 
         [0004]    2. Description of Related Art 
         [0005]    The automotive industry has actively sought to reduce pollutants in exhaust gases. One method for reducing pollutants in exhaust gases is by using canister purge 
         [0006]    Generally, gasoline includes a mixture of hydrocarbons ranging from higher volatility butanes (C4) to lower volatility C8 to C10 hydrocarbons. Such gasoline is stored in a fuel tank. However, when the temperature of the surroundings is high or vapor pressure in the fuel tank is increased by movement of the vapor, fuel vapor leaks through crevices of the fuel tank. To prevent leakage of the fuel vapor, the fuel vapor is vented into a canister when the vapor pressure in the fuel tank is increased. 
         [0007]    The canister has absorbent material (i.e., activated carbon) for absorbing the fuel vapor from the fuel tank. If the hydrocarbons HC absorbed by the canister are vented into the atmosphere, the engine does not meet exhaust gas regulations. Therefore, an engine control unit operates a purge control solenoid valve in order to vent the hydrocarbons absorbed by the canister into the engine. 
         [0008]    Meanwhile, a hybrid vehicle is a vehicle having both an engine for generating a power by combusting a fuel and a motor for outputting a power of a battery. Recently, use of an engine becomes shortened for enhancement of fuel economy, and accordingly time for burning fuel evaporation of the canister becomes shortened. Since the fuel evaporation absorbed in the canister increases but the fuel evaporation purged from the canister decreases, overflow of the fuel evaporation may occur. 
         [0009]    The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art. 
       BRIEF SUMMARY OF THE INVENTION 
       [0010]    Various aspects of the present invention are directed to provide a canister for vehicles and a fuel supply system provided with the same having advantages of preventing overflow of fuel evaporation and improving fuel economy. 
         [0011]    In an aspect of the present invention, the canister for vehicles provided with an activated carbon therein so as to absorb an evaporation gas evaporated from a fuel tank, and releasing the absorbed evaporation gas so as to supply to an engine, may include a housing to receive the activated carbon therein, an evaporation gas supply passage formed to the housing to be fluid-connected to the fuel tank and receive the evaporation gas from the fuel tank, an air passage formed to the housing and selectively receiving an air from the exterior of the housing, and a purge passage formed to the housing to be fluid-connected to a purge line so as to supply the evaporation gas to the engine according to a flow of the received air, wherein the purge passage may be provided with a first purge passage formed to the housing and directly fluid-connecting the housing to the purge line and a second purge passage formed to the housing and having an end portion positioned inside the first purge passage or the purge line so as to be fluid-connected to the purge line. 
         [0012]    The end portion of the second purge passage extends along a flow direction of the evaporation gas passing through the first purge passage or the purge line. 
         [0013]    The end portion of the second purge passage may be formed of a venturi, a diameter of which may be smaller than that of the other parts of the second purge passage, such that a speed of the evaporation gas passing through the second purge passage may be increased. 
         [0014]    The first and second purge passage may be connected respectively to first and second purge holes formed respectively at different positions of the housing, and the end portion of the second purge passage penetrates a part of an exterior circumference of the first purge passage or the purge line and may be positioned in the first purge passage or the purge line. 
         [0015]    In another aspect of the present invention, the fuel supply system may include a fuel tank connected to a refueling line so as to receive a fuel, exhausting an evaporation gas therein through an evaporation gas line, and supplying the fuel through a fuel supply line, an engine connected to the fuel supply line so as to receive the fuel from the fuel tank, and connected to an intake passage so as to receive an air, a purge line connected to the intake passage, and a canister provided with a housing to receive an activated carbon for absorbing the evaporation gas therein through the evaporation gas line, and may include an evaporation gas supply passage formed to the housing and fluid-connected to the evaporation gas line so as to receive the evaporation gas, an air passage connected to an air supply line so as to receive an air from the exterior of the housing, and a purge passage formed to the housing to be fluid-connected to the purge line, releasing the evaporation gas absorbed at the activated carbon according to a flow of the air received through the air passage, and supplying the evaporation gas to the intake passage, wherein the purge passage may be provided with a first purge passage formed to the housing to directly fluid-connect the housing to the purge line and a second purge passage formed to the housing and having an end portion positioned in the first purge passage or the purge line so as to be fluid-connected to the purge line. 
         [0016]    The end portion of the second purge passage extends along a flow direction of the evaporation gas passing through the first purge passage or the purge line. 
         [0017]    The end portion of the second purge passage may be formed of a venturi, a diameter of which may be smaller than that of the other parts of the second purge passage, such that a speed of the evaporation gas passing through the second purge passage may be increased. 
         [0018]    The first and second purge passage may be connected respectively to first and second purge holes formed respectively at different positions of the housing, and the end portion of the second purge passage penetrates a part of an exterior circumference of the first purge passage or the purge line and may be positioned in the first purge passage or the purge line. 
         [0019]    A purge control solenoid valve for selectively supplying the evaporation gas of the canister to the intake passage may be mounted at the purge line, and a drain cut valve for selectively supplying the air of the exterior of the housing may be mounted at the air supply line. 
         [0020]    The purge control solenoid valve and the drain cut valve may be simultaneously controlled. 
         [0021]    The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a schematic diagram of a fuel supply system according to an exemplary embodiment of the present invention. 
           [0023]      FIG. 2  is a cross-sectional view of a canister for vehicles according to an exemplary embodiment of the present invention. 
           [0024]      FIG. 3  is a partial enlarged view of  FIG. 2 . 
       
    
    
       [0025]    It should be understood that the appended drawings are not necessarily to scale, presenting a somewhat simplified representation of various features illustrative of the basic principles of the invention. The specific design features of the present invention as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes will be determined in part by the particular intended application and use environment. 
         [0026]    In the figures, reference numbers refer to the same or equivalent parts of the present invention throughout the several figures of the drawing. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0027]    Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0028]    An exemplary embodiment of the present invention will hereinafter be described in detail with reference to the accompanying drawings. 
         [0029]      FIG. 1  is a schematic diagram of a fuel supply system according to an exemplary embodiment of the present invention. 
         [0030]    As shown in  FIG. 1 , a fuel supply system according to an exemplary embodiment of the present invention includes an engine  10 , a fuel tank  20 , and a canister  30 . 
         [0031]    The engine  10  generates power for driving a vehicle by burning a fuel and an air, and includes an intake manifold for receiving the air and the fuel and an exhaust manifold for exhausting an exhaust gas generating at combustion process. The intake manifold is connected to an intake passage  12  and receives the air from the exterior. In addition, a throttle valve  14  is mounted at the intake passage  12  and controls air amount supplied to the intake manifold. 
         [0032]    The fuel tank  20  stores the fuel and is connected to the engine  10  through a fuel supply line  26  so as to supply the fuel to the engine  10 . The fuel tank  20  is connected to a refueling line  22  so as to receive the fuel. In addition, the fuel tank  20  is connected to the canister  30  through an evaporation gas line  24  so as to supply evaporation gas generated in the fuel tank  20  to the canister  30 . Herein, the evaporation gas means fuel evaporation. 
         [0033]    The canister  30  absorbs the evaporation gas of the fuel tank  20 , releases the absorbed evaporation gas according to a control of a control portion, and supplies the evaporation gas to the engine  10 . For this purpose, the canister  30  is provided with an activated carbon  38  therein. A plurality of micropores is formed at the activated carbon  38 , and the evaporation gas is absorbed in the plurality of micropores. In addition, the canister  30  further includes an evaporation gas supply passage  32 , a purge passage  34 , and an air passage  36 . 
         [0034]    The evaporation gas supply passage  32  is connected to the evaporation gas line  24  and receives the evaporation gas of the fuel tank  20 . The evaporation gas supplied in the canister  30  through the evaporation gas supply passage  32  is absorbed at the activated carbon  38 . 
         [0035]    The purge passage  34  is connected to a purge line  50 , and the purge line  50  is connected to the intake passage  12  downstream of the throttle valve  14 . The purge passage  34  selectively supplies the evaporation gas in the canister  30  to the engine  10  through the purge line  50  and the intake passage  12 . 
         [0036]    The air passage  36  is connected to an air supply line  60  and selectively receives the air of the exterior. If the air of the exterior is supplied in the canister  30  through the air passage  36 , the evaporation gas absorbed at the activated carbon  38  is released by difference between negative pressure generated at the intake passage  12  downstream of the throttle valve  14  and atmospheric pressure, and the released evaporation gas is supplied to the intake passage  12  together with the air supplied to the canister  30 . That is, the evaporation gas of the canister  30  is supplied to the engine  10  according to a flow of the air supplied through the air passage  36 . 
         [0037]    Meanwhile, the fuel supply system according to the exemplary embodiment of the present invention further includes a drain cut valve  40  mounted at the air supply line  60  and a purge control solenoid valve  52  mounted at the purge line  50 . 
         [0038]    The drain cut valve  40  controls the air supplied to the canister  30  through the air supply line  60 , and the purge control solenoid valve  52  controls the evaporation gas supplied from the canister  30  to the intake passage  12  through the purge line  50 . Such drain cut valve  40  and purge control solenoid valve  52  may be simultaneously controlled by the control portion. That is, the purge control solenoid valve  52  is open if the drain cut valve  40  is open, and the purge control solenoid valve  52  is close if the drain cut valve  40  is close. 
         [0039]    Hereinafter, the canister  30  according to an exemplary embodiment of the present invention will be described in further detail with reference to  FIG. 2  and  FIG. 3 . Particularly, the canister  30  according to an exemplary embodiment of the present invention is similar to a conventional canister except the purge passage  34 . Therefore, the purge passage  34  will be described in detail. 
         [0040]      FIG. 2  is a cross-sectional view of a canister for vehicles according to an exemplary embodiment of the present invention, and  FIG. 3  is a partial enlarged view of  FIG. 2 . 
         [0041]    As shown in  FIG. 2  and  FIG. 3 , the canister  30  has a housing  45  provided with a first purge hole  101  and a second purge hole  103  formed respectively at different positions of the housing  45 . Therefore, the evaporation gas of the canister  30  flows out through the first purge hole  101  and the second purge hole  103 . In addition, the purge passage  34  of the canister  30  includes a first purge passage  100  and a second purge passage  102 . The first purge passage  100  is connected to the first purge hole  101  and the second purge passage  102  is connected to the second purge hole  103 . The first purge passage  100  and the second purge passage  102  are connected to each other at the purge line  50 . Concretely, the first purge passage  100  is directly connected to the purge line  50  (i.e., an end of the first purge passage  100  is connected to an end of the purge line  50 ). The second purge passage  102  penetrates a part of an exterior circumference of the first purge passage  100  or the purge line  50  and an end of the second purge passage  102  is positioned in the first purge passage  100  or the purge line  50 . 
         [0042]    In addition, the end portion  104  of the second purge passage  102  extends along a flow of the evaporation gas passing through the first purge passage  100  or the purge line  50 . That is, the end portion  104  of the second purge passage  102  is formed to the same direction of the first purge passage  100  or the purge line  50 . Further, the second purge passage  102  is formed of a venturi. That is, a diameter of the end portion  104  of the second purge passage  102  is smaller than that of the other parts of the second purge passage  102 . Accordingly, a speed of the evaporation gas passing through the second purge passage  102  and flowing out to the first purge passage  100  or the purge line  50  increases. In addition, since the speed of the evaporation gas passing through the second purge passage  102  increases, a pressure near the second purge passage  102  in the first purge passage  100  or the purge line  50  is lowered (Beroulli&#39;s theorem). Therefore, a flow rate of the evaporation gas passing through the first purge passage  100  increases. 
         [0043]    Since a purge amount of the canister  30  is increased under the same purge condition, overflow of the evaporation gas may be prevented. 
         [0044]    In addition, since the activated carbon is not heated but the purge passage is added, manufacturing cost may increase a little. 
         [0045]    Meanwhile, it is exemplified in an exemplary embodiment of the present invention that the first and second purge holes  101  and  103  are formed at the different positions, but the scope of the present invention is not limited to this. That is, the second purge hole  103  having smaller diameter may be formed in the first purge hole  101  (by attaching a part of an exterior circumference of the first purge hole  101  with a part of an exterior circumference of the second purge hole  103 ). In this case, the second purge passage  102  is disposed in the first purge passage  100  and the second purge passage  102  is formed of the venturi. 
         [0046]    As described above, since the second purge passage formed of the venture is disposed in the first purge passage and the purge amount of the canister increases according to an exemplary embodiment of the present invention, the overflow of the evaporation gas may be prevented. 
         [0047]    In addition, since the engine is not operated or the activated carbon is not heated for preventing the overflow of the evaporation gas, fuel economy may improve. 
         [0048]    Further, since additional devices for preventing the overflow of the evaporation gas, manufacturing cost may not be increased. 
         [0049]    For convenience in explanation and accurate definition in the appended claims, the terms “upper”, “lower”, “inner” and “outer” are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures. 
         [0050]    The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.