Canister for vehicles and fuel supply system provided with the same

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.

CROSS-REFERENCE TO RELATED APPLICATION

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

1. Field of the Invention

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.

2. Description of Related Art

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

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.

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.

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.

BRIEF SUMMARY OF THE INVENTION

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

The purge control solenoid valve and the drain cut valve may be simultaneously controlled.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1is a schematic diagram of a fuel supply system according to an exemplary embodiment of the present invention.

As shown inFIG. 1, a fuel supply system according to an exemplary embodiment of the present invention includes an engine10, a fuel tank20, and a canister30.

The engine10generates 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 passage12and receives the air from the exterior. In addition, a throttle valve14is mounted at the intake passage12and controls air amount supplied to the intake manifold.

The fuel tank20stores the fuel and is connected to the engine10through a fuel supply line26so as to supply the fuel to the engine10. The fuel tank20is connected to a refueling line22so as to receive the fuel. In addition, the fuel tank20is connected to the canister30through an evaporation gas line24so as to supply evaporation gas generated in the fuel tank20to the canister30. Herein, the evaporation gas means fuel evaporation.

The canister30absorbs the evaporation gas of the fuel tank20, releases the absorbed evaporation gas according to a control of a control portion, and supplies the evaporation gas to the engine10. For this purpose, the canister30is provided with an activated carbon38therein. A plurality of micropores is formed at the activated carbon38, and the evaporation gas is absorbed in the plurality of micropores. In addition, the canister30further includes an evaporation gas supply passage32, a purge passage34, and an air passage36.

The evaporation gas supply passage32is connected to the evaporation gas line24and receives the evaporation gas of the fuel tank20. The evaporation gas supplied in the canister30through the evaporation gas supply passage32is absorbed at the activated carbon38.

The purge passage34is connected to a purge line50, and the purge line50is connected to the intake passage12downstream of the throttle valve14. The purge passage34selectively supplies the evaporation gas in the canister30to the engine10through the purge line50and the intake passage12.

The air passage36is connected to an air supply line60and selectively receives the air of the exterior. If the air of the exterior is supplied in the canister30through the air passage36, the evaporation gas absorbed at the activated carbon38is released by difference between negative pressure generated at the intake passage12downstream of the throttle valve14and atmospheric pressure, and the released evaporation gas is supplied to the intake passage12together with the air supplied to the canister30. That is, the evaporation gas of the canister30is supplied to the engine10according to a flow of the air supplied through the air passage36.

Meanwhile, the fuel supply system according to the exemplary embodiment of the present invention further includes a drain cut valve40mounted at the air supply line60and a purge control solenoid valve52mounted at the purge line50.

The drain cut valve40controls the air supplied to the canister30through the air supply line60, and the purge control solenoid valve52controls the evaporation gas supplied from the canister30to the intake passage12through the purge line50. Such drain cut valve40and purge control solenoid valve52may be simultaneously controlled by the control portion. That is, the purge control solenoid valve52is open if the drain cut valve40is open, and the purge control solenoid valve52is close if the drain cut valve40is close.

Hereinafter, the canister30according to an exemplary embodiment of the present invention will be described in further detail with reference toFIG. 2andFIG. 3. Particularly, the canister30according to an exemplary embodiment of the present invention is similar to a conventional canister except the purge passage34. Therefore, the purge passage34will be described in detail.

FIG. 2is a cross-sectional view of a canister for vehicles according to an exemplary embodiment of the present invention, andFIG. 3is a partial enlarged view ofFIG. 2.

As shown inFIG. 2andFIG. 3, the canister30has a housing45provided with a first purge hole101and a second purge hole103formed respectively at different positions of the housing45. Therefore, the evaporation gas of the canister30flows out through the first purge hole101and the second purge hole103. In addition, the purge passage34of the canister30includes a first purge passage100and a second purge passage102. The first purge passage100is connected to the first purge hole101and the second purge passage102is connected to the second purge hole103. The first purge passage100and the second purge passage102are connected to each other at the purge line50. Concretely, the first purge passage100is directly connected to the purge line50(i.e., an end of the first purge passage100is connected to an end of the purge line50). The second purge passage102penetrates a part of an exterior circumference of the first purge passage100or the purge line50and an end of the second purge passage102is positioned in the first purge passage100or the purge line50.

In addition, the end portion104of the second purge passage102extends along a flow of the evaporation gas passing through the first purge passage100or the purge line50. That is, the end portion104of the second purge passage102is formed to the same direction of the first purge passage100or the purge line50. Further, the second purge passage102is formed of a venturi. That is, a diameter of the end portion104of the second purge passage102is smaller than that of the other parts of the second purge passage102. Accordingly, a speed of the evaporation gas passing through the second purge passage102and flowing out to the first purge passage100or the purge line50increases. In addition, since the speed of the evaporation gas passing through the second purge passage102increases, a pressure near the second purge passage102in the first purge passage100or the purge line50is lowered (Beroulli's theorem). Therefore, a flow rate of the evaporation gas passing through the first purge passage100increases.

Since a purge amount of the canister30is increased under the same purge condition, overflow of the evaporation gas may be prevented.

In addition, since the activated carbon is not heated but the purge passage is added, manufacturing cost may increase a little.

Meanwhile, it is exemplified in an exemplary embodiment of the present invention that the first and second purge holes101and103are formed at the different positions, but the scope of the present invention is not limited to this. That is, the second purge hole103having smaller diameter may be formed in the first purge hole101(by attaching a part of an exterior circumference of the first purge hole101with a part of an exterior circumference of the second purge hole103). In this case, the second purge passage102is disposed in the first purge passage100and the second purge passage102is formed of the venturi.

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.

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.

Further, since additional devices for preventing the overflow of the evaporation gas, manufacturing cost may not be increased.