Claims:We Claim:
1. A method of re-distributing fuel in an engine (14) of a vehicle, said method comprising :
- calculating speed of rotation of a trigger wheel (18) connected to a crankshaft (16) of said engine (14), when said engine (14) is in an operating mode;
characterized in that:
- detecting a predefined speed range stored in a control unit (12) corresponding to a current gear of a vehicle;
- determining a deviation in a signal from said trigger wheel (18) based said calculated rotational speed of said trigger wheel (18) and said detected predefined speed range;
- re-distributing said fuel in said engine by said control unit (12) based on said determined error, such that equal torque is obtained from all cylinders of said engine (14).
2. The method as claimed in claim 1, further comprising a step of receiving a signal from a sensor (22) mounted on said trigger wheel (18), when at least one tooth (20) of said trigger wheel (18) adapted to pass said sensor (22).
3. The method as claimed in claim 1, wherein said deviation in said signal corresponding to at least one tooth (20) of said trigger wheel (18) is determined based on said signal received from said sensor (22).
4. The method as claimed in claim 1, wherein said sensor (22) adapted to transmit said signal to said control unit (12) based on a width of said at least one tooth (20) of said trigger wheel (18).
5. A control unit (12) adapted to re-distribute fuel in an engine (14) of a vehicle (10), said control unit (12) adapted to :
- calculate speed of rotation of a trigger wheel (18) connected to a crankshaft (16) of said engine (14), when said engine (14) is in an operating mode;
- detect a predefined speed range stored in said control unit (12) corresponding to a current gear of said vehicle (10);
- determine a deviation in a signal from said trigger wheel (18) based on said calculated rotational speed of said trigger wheel (16) and said detected predefined speed range;
- re-distribute said fuel in said engine (14) based on said determined error, such that equal torque is obtained from all cylinders of said engine (14).
6. The control unit (12) as claimed in claim 1, is connected to a sensor (22) mounted on said trigger wheel (18), said control unit (12) adapted to receive said signal from said sensor (22), when at least one tooth (20) of said trigger wheel (18) is adapted to pass said sensor (22).
7. The control unit (12) as claimed in claim 1, wherein said sensor (22) adapted to transmit said signal based on a width of at least one tooth (20) of said trigger wheel (18).
8. The control unit (12) as claimed in claim 1, wherein said deviation in said signal is determined based on said received signal from said sensor (22).
, Description:Complete Specification:
The following specification describes and ascertains the nature of this invention and the manner in which it is to be performed.
Field of the invention
[0001] This invention relates to a method of re-distributing fuel in an engine of a vehicle.

Background of the invention
[0002] The effects of imperfect fuel distribution on engine performance were well known to automotive industry. Fuel distribution in engines has significant influence on the cyclic stability of charge ignition and combustion, and hence on engine performance parameters related to the variation of combustion and heat release. There are numerous ways to influence in-cylinder fuel distribution by means of mixture preparation systems, engine aspiration or by combustion chamber geometry itself. However, methods to observe in-cylinder fuel distribution are scarce, and very often charge distribution—homogeneous or highly stratified—is just heuristically assessed, based on engine performance data. During engine operation, the fuel is supplied by gravity from fuel tank to the primary filter where coarse impurities are removed. The fuel injection pump supplies fuel under high pressure to the injectors through high-pressure pipes.

[0003] Prior art patent application discloses US5412949 A fuel distribution system for a gas-turbine engine is disclosed which ensures homogenous fuel supply to all fuel injectors in order to avoid local fuel oversupplies that might cause local overheating of the turbine blades. The fuel system compensates for the deleterious load factors experienced by the aircraft and the gas turbine engine that affect the fuel distribution to the fuel injectors. The system supplies fuel to a plurality of fuel injectors arranged in an annular array so as to inject fuel into an annular combustion chamber of the gas turbine engine. The system has a closed loop, generally annular fuel connector line and a plurality of fuel distributors connected in parallel to the fuel connector line so that fuel passes into a central chamber of each of the distributors.

Brief description of the accompanying drawing
[0004] Different modes of the invention are disclosed in detail in the description and illustrated in the accompanying drawing:

[0005] FIG. 1 illustrates a control unit in a vehicle in accordance with one embodiment of the invention;
[0006] FIG. 2 illustrates a method of re-distributing fuel in an engine of a vehicle.

Detailed description of the embodiments
[0007] FIG. 1 illustrates a control unit 12 adapted to re-distribute fuel in an engine 14 of a vehicle 10 according to one embodiment of the invention. The control unit 12 calculates the speed of rotation of a trigger wheel 18 connected to a crankshaft 16 of the engine 14, when the engine 14 is in an operating mode. The control unit 12 detects a predefined speed range stored in the control unit 12 corresponding to a current gear of the vehicle 10. The control unit 12 determines a deviation in a signal from the trigger wheel 18 based on the calculated rotational speed of the trigger wheel 16 and the detected predefined speed range. The control unit 12 re-distributes the fuel in the engine 14 based on the determined deviation in the signal, such that equal torque is obtained from all cylinders of the engine14.

[0008] Further construction of the control unit 12 and the components of the control unit 12 in the vehicle is explained further. The engine 14 of the vehicle 10 comprises multiple cylinders. Due to the errors while manufacturing the cylinder, the cylinders present in the engine 14 will not be identical. The trigger wheel 18 is connected to the crankshaft 16 of the vehicle 10 and a sensor 22 is mounted on the trigger wheel 18. The trigger wheel 18 comprises multiple tooth 20 of different size and shape. The sensor 22 is chosen from the group of sensors like an EPM (engine position module) sensor, a proximity sensor, a hall-effect sensor or the like. The sensor 22 detects the tooth 20 of the trigger wheel 18 and transmits the signal to the control unit 12 based on the width of the tooth 20 of the trigger wheel 18. According to one embodiment of the invention, the control unit 12 is an engine control unit. The control unit 12 is not restricted to above mentioned one, but can be any control unit 12 in the vehicle as known to a person skilled in the art. The control unit 12 is chosen from a group of control units comprising a microprocessor, a microcontroller, an integrated digital circuit or the like. The vehicle 10 further comprises a gear box 24 connected to the control unit 2 and the engine 14. The control unit 12 receives the information of the current gear in which the vehicle 10 is operating from the gear box 24.

[0009] FIG.2 illustrates a method of re-distributing fuel in an engine 14 of a vehicle. In step S1, speed of rotation of a trigger wheel 18 connected to a crankshaft 16 of the engine 14 is calculated, when the engine 14 is in an operating mode. In step S2, a predefined speed range stored in a control unit 12 corresponding to a current gear of a vehicle 10 is determined. In step S3, a deviation in a signal from the trigger wheel 18 is determined based on the calculated rotational speed of the trigger wheel 18 and the detected predefined speed range. In step S4, the fuel in the engine 14 is re-distributed by the control unit 12 based on the determined deviation in the signal, such that equal torque is obtained from all cylinders of the engine 14.

[0010] the method is explained in details as follows. The control unit 12 comprises a database having multiple predefined speed range mapped for corresponding gears of the vehicle 10. For instance, a predefined speed range of 2800 rpm – 1500rpm is mapped for the second gear of the vehicle 10. The trigger wheel 18 comprising multiple tooth 20 rotates and moves a piston of the engine 14 in an engine cylinder, when the vehicle is in operating condition. The trigger wheel 18 that is connected to the crankshaft 16 rotates with the movement of the crankshaft 16. At least one tooth 20 of the trigger wheel 18 passes the sensor during this rotation, and the signal from each passing of the tooth 20 of the trigger wheel 18 is transmitted to the control unit 12. The control unit 12 further determines the rotational speed of the trigger wheel 18 based on the current gear of the vehicle and the predefined speed range (that are stored in the control unit) corresponding for the current gear in which the vehicle 10 is operating. The control unit 12 determines the deviation in the signal from the sensor 22 corresponding to at least one tooth of the trigger wheel 18 based on the rotational speed of the trigger wheel 18, signal from the sensor 22 and the detected predefined speed range. From the determined deviation of the signal corresponding to at least one tooth 20 of the trigger wheel 18, the control unit 12 re-distributes the fuel in each of the cylinder , during the operating mode.

[0012] With the above-disclosed method, an effective re-distribution of the fuel into the cylinders of the engine 14 can be achieved. The re-distribution of the fuel leads to equal torque output from all the cylinders of the engine 14, thus increasing the overall efficiency of the engine 14. Since, the method uses the existing components in the vehicle 10, the above method makes it a low-cost solution.

[0011] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The scope of the invention is only limited by the scope of the claims.