Patent ID: 7730717
Filing Date: 2010-06-08
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. A system for controlling an internal combustion engine whose operation is switchable between a compression-ignition operation in which an air-fuel mixture supplied to a combustion chamber auto-ignites to burn owing to compression and a spark-ignition operation in which the air-fuel mixture is ignited to burn by a spark of a spark plug installed in the combustion chamber, comprising: a permissible condition determiner that determines whether a predetermined permissible condition to permit switching from the spark-ignition operation to the compression-ignition operation is satisfied at least in part via calculating upper and lower limits of required torque of the engine depending on whether or not combustion-ignition is possible; and a switching permitter that permits switching from the spark-ignition operation to the compression-ignition operation when the predetermined permissible condition is satisfied, wherein the permissible condition determiner determines whether a required torque of the engine falls within a predetermined region defined by an coolant temperature and engine speed, and determines that the predetermined permissible condition is satisfied when the required torque falls within the predetermined region, wherein a lower limit of the predetermined region is defined to decrease with decreasing coolant temperature, whereby a region of the compression-ignition operation is expanded.