Method and apparatus to control transition between HCCI and SI combustion in a direct-injection gasoline engine
A method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between HCCI and SI modes includes providing a low-lift intake valve, un-throttled stoichiometric SI operation intermediate a low-lift exhaust and intake valve HCCI mode and a high-lift exhaust and intake valve, un-throttled SI mode.
1. Method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition mode and spark ignition modes, comprising:
providing a low-lift intake valve, un-throttled stoichiometric spark ignition operation intermediate a low-lift exhaust and intake valve homogeneous charge compression ignition mode and a high-lift exhaust and intake valve, un-throttled spark ignition mode.
2. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 1 , wherein said intermediate low-lift intake valve, un-throttled stoichiometric spark ignition operation further comprises low-lift exhaust valve, un-throttled stoichiometric spark ignition operation.
3. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 2 , wherein said engine comprises a single intake port per cylinder.
4. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 2 , wherein said engine comprises multiple intake ports per cylinder.
5. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 4 , wherein at least one intake port includes an intake port throttle.
6. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 1 , wherein said intermediate low-lift intake valve, un-throttled stoichiometric spark ignition operation further comprises high-lift exhaust valve, un-throttled stoichiometric spark ignition operation.
7. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 6 , wherein said engine comprises a single intake port per cylinder.
8. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 6 , wherein said engine comprises multiple intake ports per cylinder.
9. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 8 , wherein at least one intake port includes an intake port throttle.
10. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 1 , wherein said engine comprises a fast cam phasing/valve timing mechanism in order to facilitate said intermediate operation in transient engine operation.
11. Method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes, wherein a gap exists between a highest load reachable with said homogeneous charge compression ignition mode and a lowest load reachable with said spark ignition mode above a threshold engine speed, comprising:
when said engine is operating above said threshold engine speed, providing a low-lift intake valve, low-lift exhaust valve, un-throttled stoichiometric spark ignition operation intermediate a low-lift exhaust and intake valve homogeneous charge compression ignition mode and a high-lift exhaust and intake valve, un-throttled spark ignition mode.
12. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 11 , wherein said engine comprises multiple intake ports per cylinder.
13. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 12 , wherein at least one intake port includes an intake port throttle.
14. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 12 , wherein at least one intake port includes an intake port throttle.
15. The method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes as claimed in claim 11 , wherein said engine comprises multiple intake ports per cylinder.
16. Method for transitioning operation of a spark-ignition, direct-injection internal combustion engine having a two-step, variable phase valvetrain between homogeneous charge compression ignition and spark ignition modes, wherein a gap exists between a highest load reachable with said homogeneous charge compression ignition mode and a lowest load reachable with said spark ignition mode above a threshold engine speed, comprising:
when said engine is operating above said threshold engine speed, providing a low-lift intake valve, high-lift exhaust valve, un-throttled stoichiometric spark ignition operation intermediate a low-lift exhaust and intake valve homogeneous charge compression ignition mode and a high-lift exhaust and intake valve, un-throttled spark ignition mode.