Patent ID: 9328688
Filing Date: 2016-05-03
CPC Classification: F02D,Y02T

Claim Text:
1. A method of controlling an internal combustion engine system having an internal combustion engine, a fuel injector which directly injects fuel into a combustion chamber of said internal combustion engine, and a supercharger which is operatively coupled to a compressor and a turbine and supercharges air into said combustion chamber, the method comprising: providing an engine operating load range of the internal combustion engine having a low-load HCCI range extending from zero torque to a first torque threshold, a high-load HCCI range extending from the first torque threshold to a higher second torque threshold, and a spark ignition (SI) range extending from the second torque threshold; injecting fuel into said combustion chamber multiple times so that a first part of the fuel is self ignited and a last part of the fuel being injected during a compression stroke or later in a cylinder cycle, when a desired torque of said internal combustion engine system is in the high-load HCCI range and when the air fuel ratio in said combustion chamber is leaner than the stoichiometric air fuel ratio; charging air when the desired torque is between the first torque threshold and the second torque threshold; increasing a pressure of air which said supercharger charges into said combustion chamber as an amount of fuel injected into said combustion chamber during a cylinder cycle increases when the desired torque is between the first torque threshold and the second torque threshold, such that a supercharge air amount at the second torque threshold is greater than a supercharge air amount at the first torque threshold, an air fuel ratio in said combustion chamber at the first torque threshold is substantially equal to an air fuel ratio in said combustion chamber at the second torque threshold, and the air fuel ratio decreases between zero torque and the first torque threshold in the low-load HCCI range; and igniting fuel injected in said combustion chamber with a spark made by a spark plug, when a desired torque for said internal combustion engine system is between the second torque threshold and above, wherein an effective compression ratio at the first torque threshold is configured to be greater than an effective compression ratio at the second torque threshold and decreases therebetween.