Patent ID: 9441570
Filing Date: 2016-09-13
CPC Classification: F02D,F02M,F02P,Y02T

Claim Text:
1. A fuel management system for a spark ignition engine where fuel is directly injected into at least one engine cylinder and where during the warmed up portion of the drive cycle, above a threshold level for the amount of directly injected fuel that is introduced into the at least one engine cylinder, particulate emissions undergo a threshold increase due to piston wetting where the threshold increase occurs when the amount of directly injected fuel exceeds the threshold level; and where the fuel management system also uses port fuel injection to introduce fuel into the at least one cylinder; and where, by using port injected fuel to substitute for directly injected fuel so as to limit the amount of directly injected fuel relative to the threshold level, the port fuel injection is used so as to enable operation at higher torque without the threshold increase in particulate emissions than would be the case if port fuel injection were not employed; and where over at least part of the torque range over which both direct injection and port injection fueling are employed, the fuel management system matches the fraction of fuel that is directly injected to that needed to prevent knock as torque is varied and wherein above the threshold level, there is a relationship between particulate emissions and an amount of fuel that is direct injected that results in a high percentage increase in the amount of particulate emissions relative to the amount below the threshold level.