Methods and systems for dual fuel injection
AssigneeFord Global Technologies, LLC
InventorsEthan D. Sanborn, Paul Hollar, Daniel Dusa, Joseph Lyle Thomas
Life of this patent
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Abstract
Methods and systems are provided for reducing fueling errors resulting from pressure pulsations in a port injection fuel rail. The pressure pulsations result from pressure pulsations generated in a high pressure fuel pump delivering fuel to both the port injection fuel rail and a direct injection fuel rail. A center of a port injection fuel pulse is repositioned on a nearest fuel rail pressure sampling point in the advanced direction to improve the accuracy of the delivered fuel pulse.
Claims19
A method for an engine, comprising:
- pressurizing fuel in a port injection fuel rail via an engine camshaft-driven high pressure fuel pump;
- intermittently sampling fuel pressure in the port injection fuel rail;
- and
- in response to a determination that a port-injection pulse of fuel delivered to the engine is smaller than a threshold, moving the port-injection pulse from an initial timing, asynchronous with the intermittent sampling, to a final timing, synchronous with the intermittent sampling.
A method for an engine, comprising:
- measuring a port injection fuel rail pressure with a frequency, the port injection fuel rail pressurized by an engine-driven high pressure piston fuel pump;
- estimating an initial timing and an initial width of a port-injection pulse of fuel injected into the engine based on a first measurement of the port injection fuel rail pressure;
- and
- selectively updating each of the initial timing and the initial width of the port-injection pulse based on a second, immediately subsequent measurement of the port injection fuel rail pressure, the initial timing asynchronous with the first and second measurements, the selectively updated timing synchronous with the second measurement.
An engine fuel system, comprising:
- an engine;
- a first fuel rail coupled to a direct injector;
- a second fuel rail coupled to a port injector;
- a high pressure mechanical fuel pump driven by the engine via a camshaft, the fuel pump delivering fuel to each of the first and second fuel rails, the first fuel rail coupled to an outlet of the high pressure mechanical fuel pump, the second fuel rail coupled to an inlet of the high pressure mechanical fuel pump;
- a pressure sensor coupled to the second fuel rail for estimating a fuel pressure;
- and
- a controller with computer readable instructions stored on non-transitory memory configured to:
- pressurize the second fuel rail via the high pressure mechanical fuel pump;
- perform a first sampling of the fuel pressure in the second fuel rail;
- calculate an initial timing and width of a port-injection pulse based on the first sampling;
- and
- if the width of the port-injection pulse is smaller than a threshold,
- advance the port-injection pulse from the initial timing to a timing corresponding to a second sampling of the fuel pressure, the second sampling immediately following the first sampling with no further sampling in-between.
Dependencies are inferred from the claim text.