Fuel Leakage Prevention Mechanism

Field of the Invention:

The present invention relates to "Fuel Leakage Prevention Mechanism" and more particularly to fuel leakage prevention mechanism for a two wheeler.

Background of the Invention:

Generally two wheelers with an internal combustion engine have a fuel tank mounted on the chassis for storing the fuel required for generating mechanical power. The vehicle is refuelled by opening a fuel tank cap. Conventional low cost fuel tank cap is fastened to the fuel tank and an anti clockwise rotation of the fuel tank cap with respect to the fuel tank opens the fuel tank. Such fuel tank caps are common with plastic fuel tank assembly.

Incomplete closure of the fuel tank cap leads to fuel leakage through the fuel tank cap during vehicle dynamic conditions like driving on bad roads and high gradient roads. Loose fuel tank cap also leads to evaporation of the fuel stored in the fuel tank. Due to vehicle vibrations, loose fuel tank cap will further detach from the fuel tank after driving for around 50-100 kilometres. Fuel leakage will lead to poor fuel mileage and paint peel off from painted parts coming in contact with the fuel. Fuel leakage can be even dangerous and might lead to fire accidents by electric short circuit in vehicle.

Therefore it is an object of the present invention to overcome the above problems associated with the conventional fuel tank cap by providing a fuel leakage prevention mechanism which overcomes the above problems.

Summary of the Invention:

The present invention has been devised in view of the above limitation and it is therefore an object of the present invention to provide a fuel leakage prevention mechanism which will ensure good fuel efficiency.

Another object of the present invention is to provide a fuel leakage prevention mechanism which will reduce the paint peeling off from the fuel tank.

Another object of the present invention is to provide a fuel leakage prevention mechanism which will improve the safety levels of the vehicle.

Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Brief Description of the Drawings:

The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein

Figure 1 is a side view of a conventional two wheeler according to this invention.

Figure 2 showing the fuel tank according to one embodiment of the present invention.

Figure 3 shows the circuit diagram when the fuel tank is not properly secured in its position according to one embodiment of the present invention.

Figure 4 shows the circuit diagram when the fuel tank is properly secured to its position according to one embodiment of the present invention.

Detailed Description of the Drawings:

It is further to be noted that the present invention is not limited to the described embodiment and many other changes and modifications may be made without departing from the scope of the appended claims.

For the purpose of illustration, it will be described with the help of a motorcycle. Referring to figure. 1, a motorcycle comprises of a frame (101), front fork (102) attached to a pivot tube (103) of the vehicle frame, a front wheel (104) attached to these front forks (102), a handle bar (105) connected to the front forks (102), a fuel tank (106) attached so as to straddle an upper part of the vehicle frame, a seat (107) attached to the upper rear portion of the vehicle frame, an engine unit (108) attached to the lower front section of the vehicle frame, a swing arm (109) attached to a lower rear section of the vehicle frame, suspended by a rear shock absorber (not shown in the drawing) from the vehicle frame and a rear wheel (110) attached to a rear end of swing arm (109). The intake system of the engine comprises of a carburettor, intake duct and an air cleaner. The exhaust system of the engine comprises of exhaust pipe and a muffler. The motorcycle is also provided with a side cover (111) for covering a side section of the vehicle frame, a seat cover for covering a rear section of the vehicle frame below the seat, a front fender (112) for covering an upper part of the front wheel (104), and a rear fender (113) for covering an upper part of the rear wheel (110). The drive from the engine (108) is transmitted from the engine to the driven wheel sprocket mounted on the rear wheel hub mounted on the rear wheel assembly.

According to one embodiment of the present invention and referring to figure 2, a fuel tank (201) is provided in a vehicle chassis for storing fuel required for generating mechanical power by combustion. The said fuel tank (201) has a removably connected fuel tank cap (202) for refuelling. The said fuel tank cap (202) is fastened to the fuel tank (201) and can be removed by rotating it in anticlockwise direction.

Referring to figure 3, the said fuel tank cap (202) is provided with at least one magnet (301), located on its outer surface. A non contact type reed switch (203) is located close to the fuel tank cap (202) by attaching it to the chassis. The said magnet (301) is placed in the outer surface of the fuel tank cap (202) by any adhesive means such that there is a change of state in the said reed switch (203) when the fuel tank cap (202) is in the securely closed position. The size of the magnet (301) and the magnetic parameters like residual flux density, coercivity is chosen such that, that there will be a change of state in the reed switch (203) only when the fuel tank cap (202) is in securely closed condition.

The output of the said reed switch (203) is connected to an electric circuit that will produce a warning signal, recognizable by the user, when the said fuel tank is not in a securely closed position.

For example, a reed switch (203) with normally closed contacts is connected to an electric lamp (302) located in the instrument cluster of the vehicle and a battery (303). When the fuel tank cap (202) is not in a securely closed position, the reed switch contact (203) gets closed and the lamp (302) in the instrument cluster will glow, warning the user about the improper closure of the said fuel tank cap (202).

Drawing reference to figure4, when the fuel tank cap (202) is in a securely closed position, the magnet will be close to the reed switch (203) and the reed switch contact gets open. As a result, the lamp (302) does not glow, indicating a safe fuel tank cap position.

In the place of a reed switch, other magnetic field sensors like Hall Effect sensor could also be used.

Other warning signals like buzzers can also be used to produce audible warning signals so that the user will securely close the fuel tank cap and then drive the vehicle.

The electric circuit can also be designed such that vehicle starting is inhibited if the fuel tank cap is not securely closed. In such a case, the ignition control unit is connected to the magnetic field sensor and the change in state of the sensor is detected by the ignition control unit and ignition is inhibited.

In another preferred embodiment of the present invention, the said fuel tank is preferably a plastic fuel tank and the magnet is moulded within the fuel tank cap.

By ensuring that the user is warned about the improper closure of the fuel tank cap, fuel leakage can be prevented and conditions like low fuel mileage, paint peel off and fire can be eliminated.

The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the claims.

We claim:

1. A fuel tank having a threaded fuel tank cap comprising:

at least one magnet attached to the fuel tank cap for providing a signal indicative of the fuel tank cap position;

a magnetic field sensor responsive to the magnet position on the fuel tank cap; and

an electric circuit for generating a warning indication.

2. A fuel tank having a threaded fuel tank cap as claimed in claim 1, wherein the said magnetic field sensor is non contact type reed switch.

3. A fuel tank having a threaded fuel tank cap as claimed in claim 1, wherein the said magnetic field sensor is any Hall Effect sensor.

4. A fuel tank having a threaded fuel tank cap as claimed in claim 1, wherein the said electric circuit comprises of a battery and a warning indication device.

5. A fuel tank having a threaded fuel tank cap as claimed in claim 2, wherein the said magnet when close to the reed switch, opens the contacts of the reed switch and thereby no warning indication.

6. A fuel tank having a threaded fuel tank cap as claimed in claim 2, wherein the said magnet when away from the reed switch, closes the contacts of the reed switch.

7. A fuel tank for a two wheeler having a threaded fuel tank cap comprising:

at least one magnet attached to the fuel tank cap for providing a signal indicative of the fuel tank cap position;

a magnetic field sensor responsive to the magnet position on the fuel tank cap; and

an electric circuit for generating a warning indication.