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US 9,346,451 B2Granted
Method and system for engine control
AssigneeFord Global Technologies, LLC
InventorsJoseph Norman Ulrey, Jianwen James Yi, Michael Howard Shelby, John Eric Rollinger
Life of this patent
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Abstract
Methods and systems are provided for slowly rotating an engine, unfueled, via a motor prior to an imminent engine restart to heat the engine. By rotating the engine so that heat generated in the compression stroke of a cylinder can be transferred to cylinder walls, thereby expediting engine warm-up. By warming the engine before a restart, particulate emissions generated during an engine cold-start due to direct injection of fuel can be reduced.
Claims19
A method, comprising:
- while propelling a hybrid vehicle via only motor torque, rotating an engine unfueled at slower than a threshold speed until a piston temperature is higher than a threshold, the threshold speed being an engine cranking speed when the engine is rotated unfueled via a starter motor.
A method for an engine, comprising:
- while propelling a hybrid vehicle via only motor torque, and in anticipation of an imminent engine restart, rotating an engine unfueled at lower than an engine cranking speed until piston temperature is higher than a threshold;
- and
- after the piston temperature is higher than the threshold,
- restarting the engine by resuming cylinder fueling.
1 more element
A method for an engine, comprising:
- delaying an engine restart until a piston temperature is brought above a threshold via engine rotation, the engine rotated unfueled at lower than an engine cranking speed.
Dependencies are inferred from the claim text.