초록 ▼

The present invention provides a method and system for purging a vapor canister in a Hybrid Electric Vehicle during vehicle idle conditions. The present invention first determines whether purging is necessary by measuring fuel tank pressure and the time since the last purge. If either of these eleme

The present invention provides a method and system for purging a vapor canister in a Hybrid Electric Vehicle during vehicle idle conditions. The present invention first determines whether purging is necessary by measuring fuel tank pressure and the time since the last purge. If either of these elements exceeds a calibratable threshold, the controller determines that the engine needs to be on and that purging must occur. An electronic throttle controller can also be used to command the throttle plate to low positions to increase intake manifold vacuum while purging. This allows for very rapid ingestion of the fuel vapor without risk of engine stalls, if used in an HEV where the engine speed is controlled by an electric motor. Upon completion of the purging process, the engine is shut "off" and the vehicle is returned to its normal idle conditions.

대표청구항 ▼

The present invention provides a method and system for purging a vapor canister in a Hybrid Electric Vehicle during vehicle idle conditions. The present invention first determines whether purging is necessary by measuring fuel tank pressure and the time since the last purge. If either of these eleme

The present invention provides a method and system for purging a vapor canister in a Hybrid Electric Vehicle during vehicle idle conditions. The present invention first determines whether purging is necessary by measuring fuel tank pressure and the time since the last purge. If either of these elements exceeds a calibratable threshold, the controller determines that the engine needs to be on and that purging must occur. An electronic throttle controller can also be used to command the throttle plate to low positions to increase intake manifold vacuum while purging. This allows for very rapid ingestion of the fuel vapor without risk of engine stalls, if used in an HEV where the engine speed is controlled by an electric motor. Upon completion of the purging process, the engine is shut "off" and the vehicle is returned to its normal idle conditions. d from the secondary chamber by a motion of the piston. 4. The multizone combustion chamber of claim 1, wherein the primary chamber is sealed from the secondary chamber by at leas one seal. 5. The multizone combustion chamber of claim 1, wherein: the piston has a central recess surrounded by a protruding circumferential wall; and the cylinder head has a central protruberance surrounded by a circumferential recess that matingly receives the protruding circumferential wall of the piston. 6. The multizone combustion chamber of claim 5, wherein: the primary chamber is defined between the central recess and, the central protruberance; and the secondary chamber is defined between the protruding circumferential wall and the circumferential recess. 7. The multizone combustion chamber of claim 5, wherein the piston comprises: inner piston rings located in the central recess; and outer piston rings located between the piston and the cylinder, wherein the piston rings seal and control frictional forces acting between adjacent translating surfaces. 8. The multizone combustion chamber of claim 5, wherein the central protruberance has piston rings disposed around the central protruberance to seal and to control frictional forces acting between adjacent translating surfaces. 9. The multizone combustion chamber of claim 5, wherein the central protruberance protrudes by an amount that is greater than an amount by which the protruding circumferential wall protrudes. 10. The multizone combustion chamber of claim 1, wherein a remaining fuel/gas mass within the secondary chamber is ignited by combined compression ignition and direct flame contact from a combusting gas communicating from the primary chamber after passage of the combusting gas between the primary chamber and the secondary chamber. 11. The multizone combustion chamber of claim 10, wherein a time at which the secondary chamber is ignited is controlled in accordance with a dimension of the primary chamber, a dimension of the secondary chamber and a motion of the piston. 12. The multizone combustion chamber of claim 1, wherein a compression ratio of the primary chamber and a compression ratio of the secondary chamber is based on the dimension of the primary chamber and the secondary chamber. 13. The multizone combustion chamber of claim 12, wherein the primary chamber traps a predetermined fraction of fuel/gas mass that is sufficient for compression ignition prior to initiating compression combustion in the secondary chamber thereafter. 14. The multizone combustion chamber of claim 12, wherein the compression ratio of the primary chamber and the compression ratio of the secondary chamber are different. 15. The multizone combustion chamber of claim 12, wherein a peak combustion pressure and a peak combustion temperature are a function of dimensions of the primary chamber and the secondary chamber and the compression ratio of the predetermined fraction of fuel/gas mass in the primary chamber. 16. The multizone combustion chamber of claim 1, wherein during a piston downstroke and at the predetermined position, segregation of the primary chamber and the secondary chamber is eliminated and combustion of the gas/fuel mixture in the secondary chamber occurs when a combusting gas in the primary chamber communicates as an ignition source with the gas/fuel mixture in the secondary chamber. 17. The multizone combustion chamber of claim 16, wherein a predetermined time at which the gas/fuel mixture in the secondary chamber is combusted is a function of at least one parameter of the primary chamber and the secondary chamber. 18. The multizone combustion chamber of claim 1, wherein an effective compression ratio of the primary chamber and an effective compression ratio of the secondary chamber are based on: a dimension of the primary chamber and a predetermined fraction of fuel/gas mass in the primary chamber, and a dimension of the secondary chamber and a remaining fuel/gas ma