Determining fuel injection pressure
AssigneeFord Global Technologies, LLC
InventorsJames Craig Smith, Darwin Allen Becker
Life of this patent
Estimating the term…
Abstract
This invention includes selecting a desired pressure for fuel injection in an internal combustion engine. The selection improves control of fuel injection by keeping the fuel in the fuel rail in a liquid state and by keeping the fuel injectors in an operating region where fuel injector fuel flow is less sensitive to changes in fuel injector pulse width.
Claims8
A method of determining a desired pressure across fuel injectors of an internal combustion engine having a fuel rail coupled to the fuel injectors which have fuel flow curves relating desired fuel mass to be metered into the engine and fuel injector pulse width, including the steps of:
- determining a first fuel injection pressure required to keep fuel in the fuel rail liquid;
- determining a second fuel injection pressure to keep the fuel injectors operating in a low-sensitivity region of their fuel flow curve;
- and
- selecting the larger of the first and second fuel injection pressures as the desired fuel injection pressure to be maintained so as to provide liquid fuel at a minimum absolute fuel injection pressure.
An apparatus for determining a desired pressure across fuel injectors of an internal combustion engine having a fuel rail coupled to the fuel injectors, said apparatus including:
- means for determining a first fuel injection pressure required to keep fuel in the fuel rail liquid;
- means for determining a second fuel injection pressure to keep the fuel injectors operating in a low-sensitivity region of their fuel flow curve;
- and
- means for selecting the larger of the first and second fuel injection pressures as the desired fuel injection pressure to be maintained so as to provide liquid fuel at a minimum absolute fuel injection pressure.
Dependencies are inferred from the claim text.