Gasoline Particulate Reduction Using Optimized Port And Direct Injection
AssigneeEthanol Boosting Systems, LLC
InventorsDaniel R. Cohn, Leslie Bromberg
Life of this patent
Estimating the term…
Abstract
Additional approaches for the reduction of particulate emissions in gasoline engines using optimized port+direct injection are described. These embodiments include control of the amount of directly injected fuel so as to avoid a threshold increase in particulates due to piston wetting and reduction of cold start emissions by use of air preheating using variable valve timing.
Claims18
A fuel management system for a spark ignition engine where fuel is directly injected and where there is a threshold BMEP at which particulate emissions start to increase at a higher rate with increasing BMEP;
- and where port fuel injection is used to increase the threshold BMEP while knock is also prevented;
- and where for at least at part of the torque range the fraction of total fueling that is provided by direct injection is matched to that needed to prevent knock as torque is changed;
- and where the matching increases the threshold BMEP relative to what it would be if knock were prevented without matching.
A spark ignition gasoline engine where fuel is directly injected and where there is a threshold BMEP at which particulate emissions start to increase at a higher rate with increasing BMEP;
- and where the threshold BMEP is increased by use of higher fuel pressure fuel injection;
- and where the higher pressure fuel injection is used to prevent the time period of direct injection from exceeding a maximum value;
- and where the maximum time period is such that all of the direct injection fueling can occur between the first crank angle that occurs during the intake stroke and a second crank angle that occurs during the compression stroke;
- and where the maximum time period decreases with increasing engine speed and increasing engine torque;
- and where particulate emissions from the directly injected fuel are greater when direct injection fueling occurs before the first crank angle or after the second crank angle.
A fuel management system for a gasoline engine that is fueled by direct injection and is also fueled by port fuel injection and where port fuel injection is used so as to prevent the time period of direct injection from exceeding a maximum value;
- and where the maximum time period decreases with increasing engine speed and increasing engine torque;
- and where the maximum time period is such that all of the direct injection fueling can occur between the first crank angle that occurs during the intake stroke and a second crank angle that occurs during the compression stroke;
- and where particulate emissions from the directly injected fuel are greater when direct injection fueling occurs before the first crank angle or after the second crank angle;
- and where during at least part of the torque range, the fraction of fuel that is provided by direct injection is matched to that needed to prevent knock as BMEP increases;
- and where the matching reduces particulate emissions relative to preventing knock without matching;
- and where drive cycle engine efficiency is greater than would be the case if only direct injection were used.
Dependencies are inferred from the claim text.