DESC:FIELD OF INVENTION

The present invention relates to an evaporative emission control system for a vehicle. The inventions in more specifically aimed at an evaporative emission control system for a three-wheeled vehicle with a rear mounted engine. The invention may also be suitably adopted for small four wheel vehicles with rear mounted engine such as quadricycle.
BACKGROUND AND PRIOR ARTS

Various emission from IC engine driven vehicles including three wheeled vehicles causes environmental pollution. One of such emission taking place from an IC-engine driven vehicle is fumes of evaporated fuel leaking out of a fuel tanks. Adoption of the evaporative emission control system has become essential to meet increasing demand to control emission of fuel vapour (evaporation gas) from the fuel tank.

Typically an evaporated fuel adsorption device such as a charcoal canister, which adsorbs vapours of fuel and discharges the same into the engine intake system is used to control evaporative emission from the fuel tank. The evaporative emission control system also includes other components such as purge pipe, purge valve, roll over valve, etc.

In compact vehicle layout such as three wheeled vehicles, appropriate packaging of evaporated fuel adsorption device is critical to ensure desired performance of the device and ease of maintenance and protection of the device.

A typical three-wheeled vehicle, is generally used for transport of passengers or goods. A passenger three-wheeler has a rear compartment behind the driver compartment. The rear compartment comprises a passenger compartment and an engine compartment. A luggage compartment may also be provided behind the passenger compartment. The engine compartment is usually positioned behind the passenger compartment and below the luggage compartment. The engine and the fuel tank are mounted on the frame and/or the body panels of the vehicle. In a goods-carrier three-wheeler, there is a carrier box/compartment behind the driver compartment, and the engine compartment is behind the driver compartment, where the engine and the fuel tank are mounted on the frame and/or the body panels.

In above described three wheel vehicle configuration the evaporated fuel adsorption device is usually packaged and positioned in the engine compartment. The engine compartment also includes other vehicle components such as air cleaner, carburetor, ignition coil, fuel tank, wiring harnesses, relay unit, etc. Due to pre-existing vehicle components in the engine compartment, the evaporated fuel adsorption device is packaged distal away from the engine on right or left hand side of the engine.

The evaporated fuel adsorption device adsorbs fuel vapours from the fuel tank and discharges the same into the engine intake system under engine suction vacuum under predefined purging condition. The process of discharge of the adsorbed fuel vapours by the evaporated fuel adsorption device under the engine suction vacuum is usually referred as purging. For effective purging performance of the evaporated fuel adsorption device, it has to be at optimal temperature. Packaging of the evaporated fuel adsorption device distal away from the engine lead to the evaporated fuel adsorption device remaining in relatively lower temperature area. Due to this purging performance of the evaporated fuel adsorption device gets affected adversely.

Further, when the evaporated fuel adsorption device is packaged distal away from the engine, length of tubing connecting the evaporated fuel adsorption device and carburetor of engine intake system increases. Due to more tube length, pressure drop across the tube increases which also affects purging performance negatively. Increased tube length also increases cost and complexity of packaging.

Additionally, when the required purging performance is not met by the evaporated fuel adsorption device, higher capacity evaporated fuel adsorption device may need to be employed. This will lead to increased cost.

When the evaporated fuel adsorption device is packaged in leftward or rightward area of the engine, it remains exposed to ground from the bottom. Due to this there are higher chances of exposure of the evaporated fuel adsorption device to the dust, dirt and water. This may become especially problematic when the vehicle is traveling in waterlogged, muddy and dusty area. Such exposure to dust, dirt and water may cause malfunction and potential damage to the evaporated fuel adsorption device.

In yet another arrangement of the evaporated fuel adsorption device, it is mounted above the level of mounting of the fuel tank. However, in such arrangement if the vehicle topples, fuel may enter into the evaporated fuel adsorption device and may cause fuel leakage, leading to potentially unsafe condition. This problem especially evident in cases where roll-over valve is not provided or the provided roll-over valve is faulty or mal-functioning. This will also damage the evaporated fuel adsorption device and may potentially cause damage to other vehicle components as well. Further, when the evaporated fuel adsorption device is positioned very close to the fuel tank, it gets saturated quickly, especially during the fuel filing at the fuel station.

Thus, it can be observed that there is need of an improved evaporative emission control system which packages the evaporated fuel adsorption device effectively to ensure good purging performance, avoid undesired pressure drop, optimize piping length and does not affect packaging of pre-existing components. Additionally, the system should also address issues and overcome the limitations of conventional systems stated above.

OBJECTIVES OF THE INVENTION
Accordingly objective of the invention is to provide an evaporative emission control system in which an evaporated fuel adsorption device is packaged effectively to ensure good purging performance.

Another objective of the invention is to provide an evaporative emission control system in which the pressure drop between an evaporated fuel adsorption device and engine intake system is not high.

Yet another objective of the invention is to provide an evaporative emission control system in which an evaporated fuel adsorption device remain protected from dust, dirt and water.

Yet another objective of the invention is to provide to provide an evaporative emission control system in which fuel leakage does not happen through an evaporated fuel adsorption device in case of vehicle toppling.

Yet another objective of the invention is to provide an evaporative emission control system that does not adversely affect or compromise layouts and positioning of the other vehicle components and systems.

Another objective of the invention is to provide an evaporative emission control system in which the tubing length is optimal.

SUMMARY OF INVENTION
With the aforementioned problems and objectives in mind, an aspect of the present invention provides an evaporative emission control system comprising an evaporated fuel adsorption device, for a vehicle;
the vehicle including a front driver compartment and a rear compartment mounted over a frame comprising plurality of long members connected together by plurality of cross members;
the rear compartment comprising an engine and a fuel tank positioned within an engine compartment;
wherein the evaporated fuel adsorption device is positioned substantially within the transmission width or the evaporated fuel adsorption device is positioned at least partially within engine width when viewed from rear side of the vehicle.

Preferably the evaporated fuel adsorption device of the evaporative emission control system is positioned such that it lies above a cylinder head of the engine.

The conventional three wheeled vehicles includes a frame having a pair of lateral frame members connected by plurality of cross members. A front driver compartment and the rear compartment including the passenger seating portion or the carrier box/compartment are mounted over the frame. The rear compartment also includes the engine compartment which is positioned lower than the passenger seating portion or the carrier box/compartment. In passenger three wheeled vehicles, additionally a luggage compartment may also be provided behind the passenger seating portion. In such vehicles, the engine compartment lies under the passenger seating portion and the luggage compartment.

The engine is mounted within the engine compartment over the frame using suitable fastening means. The engine is connected to a transmission system to transmit the power to wheels of the vehicle. The fuel tank is also provided within the engine compartment and preferably positioned above the level of the engine and packaged towards left or right side of the engine.

In such vehicle configuration, the evaporated fuel adsorption device of the evaporative emission control system is positioned at least partially above the lowest point of fuel tank but below the top level of fuel tank. Further, the evaporated fuel adsorption device is preferably positioned inline or at least partially ahead of fuel tank when viewed from side. Such positioning of the evaporated fuel adsorption device ensure that the fuel will not enter into the evaporated fuel adsorption device in case vehicle topples and avoids fuel leakage in absence of roll-over valve or faulty roll-over valve. Thus, avoiding potentially unsafe condition.

In yet another aspect of the invention, the evaporated fuel adsorption device is positioned distal away from the cross members and the long members of the frame. The evaporated fuel adsorption device may also be disposed at least partially within the engine width and specifically substantially above the engine and between the air filter and the fuel tank which are mounted on left and right side of the engine. Thus ensuring compact arrangement. The evaporated fuel adsorption device is packaged substantially within transmission width when viewed from rear side of vehicle.

For positioning the evaporated fuel adsorption device in various embodiments described above, the evaporated fuel adsorption device may be mounted on body panel or on frame members or on engine or on fuel tank. To ensure the desired positioning of the evaporated fuel adsorption device in the rear compartment, the evaporated fuel adsorption device can be mounted directly on body panel or on frame members or on engine or on fuel tank. Alternately, a suitable bracket arrangement may be employed to get the desired positioning of the evaporated fuel adsorption device.

In yet another aspect of the invention, while mounting of the evaporated fuel adsorption device can be oriented vertically or horizontally or at an angle with the horizontal plane as per the design requirement and packaging space available. Further, the evaporated fuel adsorption device of any shape for e.g. rectangular box type, cylinder type, etc. can be employed as per design requirements.

Other associated components of the evaporative emission control system such as purge valve, tubing associated with the evaporated fuel adsorption device, etc. is also positioned in the rear compartment of the vehicle. These associated components are connected and packaged in conventional manner with reference to the evaporated fuel adsorption device.

Since the evaporated fuel adsorption device is mounted at least partially within engine width, it remain in the proximity of the intake system of the engine. This ensures that purge path connecting the engine intake system / the carburetor and the evaporated fuel adsorption device can be kept short so as to efficiently send evaporated fuel to the intake system. The optimal tubing length of the purge path also eliminates the undesired pressure drop across the purge path and thus ensuring good purging performance. Further, as the evaporated fuel adsorption device is in proximity of engine, it remains in optimal temperature zone and the desired purging performance is easily achieved. This eliminates need using higher capacity evaporated fuel adsorption device. The entire arrangement helps to optimize the cost and keep the system compact.

It is to be noted that though above description is in reference with conventional three wheeled vehicle with rear mounted engine, the invention can be suitably adopted for compact four wheeled vehicles with rear mounted engine such as quadricycles.

In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF DRAWINGS
In the drawings:

Figure 1 is an orthogonal view of rear side of the three wheeled vehicle with an evaporative emission control system according to one of the embodiments of the invention.
Figure 2 is a rear view of the three wheeled vehicle shown in figure 1.
Figure 3 is a top view of the three wheeled vehicle shown in figure 1.
Figure 4 is an orthogonal view of rear side of the three wheeled vehicle with an evaporative emission control system according another embodiments of the invention.
Figure 5 is a rear view of the three wheeled vehicle shown in figure 4.
Figure 6 is a top view of the three wheeled vehicle shown in figure 4.

The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
Description of preferred but non-limiting embodiments of the present invention will now follow with reference to the above drawings. The fuel cylinder arrangement in reference to a passenger vehicle is explained though the figures and following detailed description however one skilled in the art will readily recognize from the following description that the arrangement can be adopted for cargo/goods carrier three wheel vehicles as well.

Referring to figure 1 to 6, a three wheeled vehicle 100 is shown. The three wheeled vehicle comprises a chassis frame having long members 25 connected together by multiple cross members 30. An operator/ driver cabin (not shown) is provided at one end of the chassis frame and a rear compartment 5 is provided behind the operator/ driver cabin supported over long members 25 and cross members 30. The rear compartment 5 includes an engine compartment 15. The rear compartment 5 may also include the passenger seating portion 35 in case of passenger vehicle or the carrier box/compartment (not shown) in case of cargo vehicle. The engine compartment 15 provided in the rear compartment 5, is positioned lower than the passenger seating portion 35 or the carrier box/compartment.

The three wheeled vehicle 100 is provided with other vehicle components (not shown) such steering handle, dashboard, operator seat, front wheel, suspension arrangement, mudguard, rear wheels, etc. in conventional manner.

In case of a passenger three wheeled vehicles, additionally a luggage compartment 85 may also be provided behind the passenger seating portion. In such vehicles, the engine compartment 15 lies under the passenger seating portion 35 and the luggage compartment 85.

In one of the embodiments of the invention as shown in figure 1 to 3, the engine 10 is mounted within the engine compartment 15 over the frame using suitable fastening means. Transmission system 95 is connected to the engine 10 for transmitting the power of engine 10 to the wheels of vehicle 100. The transmission system 95 is provided downward of the engine 10.The fuel tank 20 is also provided within the engine compartment 15 and preferably positioned above the level of the engine 10 and packaged towards right of the engine 10. An air cleaner 40 is provided on the left side of the engine 10 and preferably positioned above the level of the engine 10.

To capture fuel vapors leaking out of the fuel tank 20, an evaporative emission control system 48 is provided in the engine compartment 15. The evaporative emission control system 48 comprises an evaporated fuel adsorption device 50 connected with the fuel tank 20 on one side through first tubing 55 and to carburetor 80 through second tubing 65 on other side. A roll over valve 60 may be provided on first tubing 55 between the evaporated fuel adsorption device 50 and the fuel tank 20. The roll over valve 60 assist in preventing the fuel leakage from the fuel tank 20 in case vehicle topples. A purge control valve 70 is provided on second tubing 65 between the evaporated fuel adsorption device 50 and the carburetor 80. The purge control valve 70 controls the purging of fuel vapors from the evaporated fuel adsorption device 50 back into the engine 10 through the carburetor 80.

For optimal performance of the evaporative emission control system 48, the evaporated fuel adsorption device 50 is packaged at least partially within the engine width when viewed from the rear side of the vehicle 100. Preferably the evaporated fuel adsorption device 50 of the evaporative emission control system 48 is positioned such that it lies above a cylinder head 12 of the engine 10. The evaporated fuel adsorption device 50 is positioned distal away from the cross members 30 and the long members 25 of the frame. Further, the evaporated fuel adsorption device 50 is disposed within between the air filter 40 and the fuel tank 20 which are mounted on left and right side of the engine 10 respectively and thus ensuring compact arrangement. The evaporator fuel adsorption device 50 is substantially packaged within the transmission width (95) when viewed from the rear side of the vehicle 100.

Such positioning of the evaporated fuel adsorption device 50, ensures that the evaporated fuel adsorption device 50 remains in optimal temperature zone and desired purging performance is easily achieved. Further, as the evaporated fuel adsorption device 50 is mounted at least partially within engine width, it remain in the proximity of the intake system & carburetor purge port of the engine 10. This ensures that the second tubing 65 connecting the carburetor 80 and the evaporated fuel adsorption device 50 can be kept short so as to efficiently send evaporated fuel to the intake system. The optimal length of second tubing 65 eliminates the undesired pressure drop across the purge path and ensures good purging performance.

The evaporated fuel adsorption device 50 of the evaporative emission control system 48 is positioned at least partially above the lowest point of fuel tank 20 but below the top level of the fuel tank 20. Further, the evaporated fuel adsorption device 50 is preferably positioned inline or at least partially ahead of fuel tank 20 when viewed from side or top of vehicle. Such positioning of the evaporated fuel adsorption device 50 ensure that the fuel will not enter into the evaporated fuel adsorption device 50 in case vehicle 100 topples and avoids fuel leakage in case if roll-over valve malfunctions.

In present embodiment, the evaporated fuel adsorption device 50 is mounted on body panel 18. Alternately, the evaporated fuel adsorption device 50 can be mounted on frame members 25, 30 or on engine 10 or on fuel tank 20. For mounting of the evaporated fuel adsorption device 50, a suitable bracket arrangement 75 may be employed to ensure desired positioning. Alternately, the evaporated fuel adsorption device 50 may be fixed using other suitable means such as strapping, snap/guide fitting, etc.

Other associated components of the evaporative emission control system 48 such as purge control valve 70, first and second tubing associated with the evaporated fuel adsorption device 55, 65 are also positioned in the rear compartment 5 of the vehicle 100 such that it does not disturb the positioning of other pre-packaged vehicle components and thus avoiding possible design changes.

Referring to figure 4 to 6, in yet another embodiment of the invention the evaporated fuel adsorption device 50 can be oriented horizontally. However, remaining packaging plan for the evaporated fuel adsorption device 50 and associated components such as purge control valve 70, first and second tubing associated with the evaporated fuel adsorption device 55, 65 is maintained same as described above.

Alternately, the evaporated fuel adsorption device 50 can be oriented at an angle with the horizontal plane as per the design requirement and packaging space available. Further, the evaporated fuel adsorption device of any shape for e.g. rectangular box type, cylinder type, etc. can be employed as per design requirements.

Proposed the evaporative emission control system ensures the evaporated fuel adsorption device positioned in optimal temperature zone and purge path connecting the engine intake system / the carburetor and the evaporated fuel adsorption device is kept short. This ensures that the undesired pressure drop across the purge path is avoided and good purging performance is achieved. By optimizing the performance of the evaporative emission control system, need of using higher capacity evaporated fuel adsorption device is also avoided. The system thus helps in ensuring good purging performance, optimizing the cost and maintaining the system compact.

Even though above description is in reference with conventional three wheeled vehicle with rear mounted engine, it can be very well understood by the person skilled in the art that invention can be suitably adopted for compact four wheeled vehicles with rear mounted engine such as quadricycles and such adoptions of the present invention are within the scope of the invention.
,CLAIMS:1. An evaporative emission control system (48) comprising an evaporated fuel adsorption device (50), for a vehicle (100) wherein;
the vehicle (100) include a front driver compartment and a rear compartment (5) mounted over a frame comprising plurality of long members (25) connected together by plurality of cross members (30);
the rear compartment comprising an engine compartment (15) provided with an engine (10) and a transmission system (95) and a fuel tank (20);
wherein the evaporated fuel adsorption device (50) is positioned substantially within transmission system (95) width when viewed from rear side of the vehicle (100).

2. An evaporative emission control system (48) comprising an evaporated fuel adsorption device (50), for a vehicle (100) wherein;
the vehicle (100) include a front driver compartment and a rear compartment (5) mounted over a frame comprising plurality of long members (25) connected together by plurality of cross members (30);
the rear compartment comprising an engine compartment (15) provided with an engine (10) and a transmission system (95) and a fuel tank (20);
wherein the evaporated fuel adsorption device (50) is positioned at least partially within engine width when viewed from rear side of the vehicle (100).

3. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the evaporated fuel adsorption device (50) is located above cylinder head (12) of the engine (10).

4. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the fuel tank (20) is provided within the engine compartment (15) and positioned above the level of the engine (10) and towards left or right side of the evaporated fuel adsorption device (50).

5. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the evaporated fuel adsorption device (50) is positioned at least partially above the lowest point of fuel tank but below the top level of fuel tank.

6. An evaporative emission control system (48) as claimed in claim 5 wherein; the evaporated fuel adsorption device (50) is positioned inline or at least partially ahead of fuel tank (20) when viewed from side or top of the vehicle (100).

7. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the evaporated fuel adsorption device (50) is positioned distal away from the cross members (30) and the long members (25) of the frame.

8. An evaporative emission control system (48) as claimed in claim 4 wherein; the evaporated fuel adsorption device (50) is positioned substantially above the engine (10) and between an air filter (40) and the fuel tank (20) which are mounted on left and right side of the engine (10) respectively.

9. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the evaporated fuel adsorption device (50) is mounted on a body panel (18) or on the frame members (25, 30).

10. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the evaporated fuel adsorption device (50) is mounted on engine (10).

11. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the evaporated fuel adsorption device (50) is mounted on fuel tank (20).

12. An evaporative emission control system (48) as claimed in claim 1 or 2 wherein; the evaporated fuel adsorption device (50) is mounted using a bracket arrangement (75).

13. An evaporative emission control system (48) as claimed in claim 1 wherein; the evaporated fuel adsorption device (50) is oriented vertically or horizontally or at an angle with the horizontal plane.

14. An evaporative emission control system (48) as claimed in claim 1 wherein; the evaporated fuel adsorption device (50) is of rectangular box type or cylinder type shape.

15. An evaporative emission control system (48) as claimed in claim 1 wherein; the evaporated fuel adsorption device (50) is connected to the fuel tank (20) on one side through a first tubing (55) and to a carburetor (80) through second tubing (65) on other side; a roll over valve (60) is provided on first tubing (55) between the evaporated fuel adsorption device (50) and the fuel tank (20); and a purge control valve (70) is provided on the second tubing (65) between the evaporated fuel adsorption device (50) and the carburetor (80).

16. An evaporative emission control system (48) as claimed in claim 12 wherein; the evaporated fuel adsorption device (50) along with carburetor (80), roll over valve (60), purge valve (70), first and second tubing (55, 65) associated with the evaporated fuel adsorption device (50) is positioned in the rear compartment of the vehicle 100.

17. An evaporative emission control system (48) as claimed in claim 1 wherein; the evaporated fuel adsorption device (50) is mounted within engine width, in proximity of an intake system of the engine (10) with optimal tubing length of the purge path.

18. An evaporative emission control system as claimed in claim 1 wherein; the vehicle (100) is a conventional three wheeled vehicle and the rear compartment include the passenger seating portion and the luggage compartment (85) provided behind the passenger seating portion and the engine compartment (15) is positioned under the passenger seating portion and the luggage compartment (85).

19. An evaporative emission control system as claimed in claim 1 wherein; the vehicle (100) is a conventional three wheeled vehicle and the rear compartment include a carrier box/compartment and the engine compartment (15) is positioned lower than the carrier box/compartment.

20. An evaporative emission control system as claimed in claim 1 wherein; the vehicle (100) is a compact four wheeled vehicles with rear mounted engine.