Patent ID: 8055435
Filing Date: 2011-11-08
Classification: F02B,F02D,Y02T

Abstract:
1. A control device for an internal combustion engine comprising: an internal combustion engine having a lean burn capability and/or an external EGR capability; an intake variable valve train capable of switching between a dual valve variable control state, in which the operating angles of a first intake valve and a second intake valve provided for each cylinder of the internal combustion engine are both variable, and a single valve small operating angle state, in which the operating angle of the second intake valve is smaller than the operating angle of the first intake valve; operating region setup means for setting up at least a high load region, a low load region in which the load is lower than in the high load region, and an extremely low load region in which the load is lower than in the low load region, as a operating region for the internal combustion engine; and operating mode control means for using, in the high load region and the extremely low load region, a stoichiometric dual valve variable control mode to provide combustion at a theoretical air-fuel ratio in the dual valve variable control state, and using, in the low load region, a lean single valve small operating angle mode to provide a lean burn in the single valve small operating angle state or an EGR single valve small operating angle mode to provide external EGR in the single valve small operating angle state, wherein the low load region is a region in which the lean single valve small operating angle mode or the EGR single valve small operating angle mode exhibits a lower specific fuel consumption than the stoichiometric dual valve variable control mode, and the extremely low load region is a region in which the stoichiometric dual valve variable control mode exhibits a lower specific fuel consumption than the lean single valve small operating angle mode or the EGR single valve small operating angle mode.