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US 8,569,903 B2Granted
Methods and systems for improved engine speed control during engine starting
AssigneeFord Global Technologies, LLC
InventorsAlex O'Connor Gibson, John Anthony DeMarco, Allan Roy Gale, Robert Michael Grant
Life of this patent
Estimating the term…
Abstract
A system for improving engine starting is disclosed. In one example, an engine starting is improved by providing a variable load to the engine during engine starting. The variable load may be provided by controlling alternator field current during the engine start.
Claims20
A system for controlling engine speed during an engine start, comprising:
- an engine;
- a first battery in electrical communication with an engine starter during an engine start;
- an alternator mechanically coupled to the engine, the alternator having a field coil excitation circuit that is electrically buffered from the first battery during the engine start, the field coil excitation circuit in electrical communication with a power source other than the first battery during the engine start;
- and
- a controller to vary a strength of a magnetic field produced by a field coil via adjusting a voltage or current supplied to the field coil excitation circuit responsive to inputs received from the engine.
2 more elements
A method of controlling engine speed, comprising:
- during an engine start,
- electrically buffering a field coil of an alternator from a battery supplying power to an engine starter;
- and
- varying an electrical property supplied to the field coil to control engine speed during the engine start responsive to inputs received at a controller from an engine, the electrical property supplied to the field coil supplied via a substantially constant voltage source.
1 more element
A method of operating an engine, comprising:
- during an engine start,
- adjusting an electrical property supplied to an alternator field coil in response to a selected engine start speed profile, wherein the alternator field coil is electrically coupled to an output of a DC/DC converter during the engine start, the DC/DC converter powered at least in part via a battery, the alternator field coil electrically buffered from the battery via the DC/DC converter.
Dependencies are inferred from the claim text.