Methods and systems for assisted direct start control
AssigneeFord Global Technologies, LLC
InventorsJoseph Norman Ulrey, Ross Dykstra Pursifull, John D. Russell
Life of this patent
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Abstract
Methods and systems are provided for expediting engine spin-down in an engine that is shutdown during engine idle-stop conditions and restarted during restart conditions. In one example, the method comprises, during an automatic engine idle-stop, turning off spark, operating a first cylinder with a rich ratio of air to injected fuel richer than a rich flammability limit, operating a second cylinder with a lean ratio of air to injected fuel leaner than a lean flammability limit, and mixing un-combusted exhaust from the first and second cylinders with exhaust, the exhaust mixture being substantially stoichiometric.
Claims20
A method, comprising:
- during an automatic engine idle-stop,
- turning off spark;
- operating a first cylinder with a rich ratio of air to injected fuel richer than a rich flammability limit;
- operating a second cylinder with a lean ratio of air to injected fuel leaner than a lean flammability limit;
- and
- mixing un-combusted exhaust from the first and second cylinders with exhaust, the exhaust mixture being substantially stoichiometric.
A method of expediting engine spin-down in an engine that is shutdown during engine idle-stop conditions and restarted during restart conditions, the method comprising:
- during an idle-stop,
- engaging a starter without applying starter current, to apply an anti-reversal torque on the engine, turning off spark, and injecting fuel into one or more engine cylinders outside flammability limits of each cylinder.
A vehicle system, comprising,
- an engine with a plurality of cylinders;
- a starter;
- and
- a control system having computer readable storage medium with code therein,
- the code carrying instructions for,
- during engine idle-stop conditions,
- engaging a starter without applying starter current to apply an anti-reversal torque on the engine;
- turning off spark;
- adjusting a throttle to bring MAP toward BP;
- operating a first cylinder with an air to injected fuel ratio richer than a rich flammability limit;
- operating a second cylinder with an air to injected fuel ratio leaner than a lean flammability limit, wherein the ratio of a total air in the first and second cylinders, to a total injected fuel in the first and second cylinders, is substantially stoichiometric.
Dependencies are inferred from the claim text.