초록 ▼

A fuel system for use in an internal combustion engine includes a plurality of fuel injectors, each injector including at least one capillary flow passage, the at least one capillary flow passage having an inlet end and an outlet end, a heat source arranged along the at least one capillary flow pass

A fuel system for use in an internal combustion engine includes a plurality of fuel injectors, each injector including at least one capillary flow passage, the at least one capillary flow passage having an inlet end and an outlet end, a heat source arranged along the at least one capillary flow passage, the heat source operable to heat a liquid fuel in the at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state, and a valve for metering fuel to the internal combustion engine, a controller to control the power supplied to the heat source of each of the plurality of fuel injectors to achieve a predetermined target temperature, a sensor for use in determining engine air flow and a sensor for measuring a value indicative of degree of engine warm-up of the internal combustion engine. According to a further aspect of the present invention, an initial liquid fuel pulse is purged from the fuel injector while the intake valve is in a substantially closed position so as to further minimize hydrocarbon emissions at startup.

대표청구항 ▼

1. A method for controlling a fuel system and delivering fuel to an internal combustion engine, the fuel system including at least one fuel injector having at least one capillary flow passage, a heat source arranged along the at least one capillary flow passage, the heat source capable of heating th

1. A method for controlling a fuel system and delivering fuel to an internal combustion engine, the fuel system including at least one fuel injector having at least one capillary flow passage, a heat source arranged along the at least one capillary flow passage, the heat source capable of heating the liquid fuel in the at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state and at least one intake valve for selectively opening and closing a passageway from said at least one fuel injector to a combustion chamber within said internal combustion engine, the method comprising the steps of:(a) measuring a value indicative of degree of engine warm-up; (b) controlling power supplied to the heat source of the at least one fuel injector to achieve a predetermined target temperature, the predetermined target temperature operable to convert the portion of liquid fuel to the vapor state; and (c) simultaneously with step (b), injecting an initial fuel pulse from said at least one fuel injector while said at least one intake valve is in a substantially closed position. 2. The method of claim 1 wherein the said at least one intake valve is in a completely closed position at the time said initial fuel pulse is injected.3. The method of claim 1 further comprising the step of returning to normal fuel injection timing after said initial fuel pulse and upon obtaining said predetermined temperature for said heat source.4. The method of claim 1 wherein said initial fuel pulse is injected against the backside of said at least one intake valve.5. The method of claim 1 wherein said fuel system comprises a plurality of fuel injectors each having at least one capillary flow passage.6. The method of claim 1 wherein said fuel system further comprises at least one fuel injector not having at least one capillary flow passage.7. A method for controlling a fuel system and delivering fuel to an internal combustion engine, the fuel system including at least one fuel injector having at least one capillary flow passage, a heat source arranged along the at least one capillary flow passage, the heat source capable of heating the liquid fuel in the at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state and at least one intake valve for selectively opening and closing a passageway from said at least one fuel injector to a combustion chamber within said internal combustion engine, the method comprising the steps of:(a) determining engine air flow; (b) measuring a value indicative of degree of engine warm-up; (c) determining a portion of liquid fuel to be converted to the vapor state by the at least one capillary flow passage, said determining step employing the values measured in steps (a)-(b); (d) controlling power supplied to the heat source of the at least one fuel injector to achieve a predetermined target temperature, the predetermined target temperature operable to convert the portion of liquid fuel to the vapor state determined in step (c); (e) simultaneously with step (d), injecting an initial fuel pulse from said at least one fuel injector while said at least one intake valve is in a substantially closed position. (f) upon said heat source achieving said predetermined target temperature, delivering the fuel to a combustion chamber of the internal combustion engine; wherein the portion of liquid fuel to be converted to the vapor state is determined to achieve minimal exhaust emissions. 8. The method of claim 7, wherein said step of determining engine air flow further comprises (i) measuring engine speed and (ii) measuring intake manifold pressure of the internal combustion engine.9. The method of claim 7, wherein said step of controlling power supplied to the heat source of the at least one fuel injector includes the step of setting a resistance value, the resistance value relatable to the predetermined target temperature.10. The method of claim 9, wherein said step of controlling power supplied to the heat source of the at least one fuel injector employs a binary power source.11. The method of claim 7, wherein the delivery of vaporized fuel to the combustion chamber of the internal combustion engine is limited to a start-up and warm-up period of operation of the internal combustion engine.12. The method of claim 9, further comprising delivering liquid fuel to the combustion chamber of the internal combustion engine when the internal combustion engine is at a fully warmed condition.13. A fuel system for use in an internal combustion engine, comprising:(a) a plurality of fuel injectors, each injector including (i) at least one capillary flow passage said at least one capillary flow passage having an inlet end and an outlet end; (ii) a heat source arranged along the at least one capillary flow passage, said heat source operable to heat the liquid fuel in said at least one capillary flow passage to a level sufficient to convert at least a portion thereof from the liquid state to a vapor state, and (iii) a valve for metering fuel to the internal combustion engine, the valve located proximate to said outlet end of said at least one capillary flow passage; (b) a controller to control the power supplied to said heat source of each of said plurality of fuel injectors to achieve a predetermined target temperature, the predetermined target temperature operable to convert the portion of liquid fuel to the vapor state; (c) said controller being operable to inject an initial fuel pulse from said at least one fuel injector while said intake valve is in a substantially closed position prior to the said predetermined target temperature being reached. 14. The fuel system of claim 13 wherein the said intake valve is in a completely closed position at the time said initial fuel pulse is injected.15. The fuel system of claim 13 wherein said controller is operable to return to normal fuel injection timing after said initial fuel pulse and upon obtaining said predetermined temperature for said heat source.16. The fuel system of claim 13 wherein said initial fuel pulse is injected against the backside of said at least one intake valve.