Cylinder charge trapping strategies based on predictive number of skips and staggered implementation of valvetrain dependent operational strategies for internal combustion engines
AssigneeTula Technology, Inc.
InventorsShikui Kevin CHEN, Louis J. SERRANO, Vijay SRINIVASAN, Elliott A. ORTIZ-SOTO, Matthew A. YOUNKINS
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Abstract
A system and method for controlling an internal combustion engine involving (1) cylinder trapping strategies where one of several pneumatic spring types are dynamically selected for cylinders based at least partially on a predicted number of upcoming skips for each of the cylinders respectively and/or (2) staggering various valvetrain dependent operational engine strategies as operating conditions permit as the internal combustion engine warms up following a cold start.
Claims37
A method of operating an internal combustion engine of a vehicle, the method comprising:
- operating the internal combustion engine such that some working cycles of cylinders of the internal combustion engine are fired while other working cycles of the cylinders are skipped;
- (a) predicting a number of upcoming successive skips for a selected cylinder;
- (b) ascertaining a type of pneumatic spring, among a multiplicity of different types of pneumatic springs, for a next skip for the select cylinder at least partially dependent on the predicted number of upcoming successive skips;
- and
- (c) commanding the selected cylinder to implement the ascertained type of pneumatic spring for the next skip of the select cylinder.
A method of operating an internal combustion engine, the method comprising:
- cold starting the internal combustion engine;
- operating the internal combustion engine following the cold start such that some firing opportunities of cylinders are fired while other firing opportunities of the cylinders are skipped;
- and
- staggering the enablement of firing fractions following the cold start such that one or more first firing fractions having relaxed valvetrain timing requirement are enabled prior to second firing fractions having more stringent valvetrain timing requirements.
A method of operating an internal combustion engine having at least some deactivatable intake and exhaust valves whose deactivation mechanism uses engine oil, the method comprising:
- cold starting the internal combustion engine;
- using a variable flow/pressure oil pump to temporarily increase an engine oil pressure until an engine oil temperature reaches a threshold temperature;
- and
- deactivating at least one of the engine's intake or exhaust valves prior to the engine oil reaching the threshold temperature.
Dependencies are inferred from the claim text.