Patent ID: 9470166
Filing Date: 2016-10-18
CPC Classification: F02D,Y02T

Claim Text:
1. A control apparatus for an internal combustion engine that is provided with a low pressure loop exhaust gas recirculation (EGR) device, which recirculates a portion of exhaust gas of the internal combustion engine as EGR gas to a portion of an intake passage of the internal combustion engine located on an upstream side of a throttle valve and includes an EGR conduit and an EGR valve, wherein the EGR valve adjusts a flow quantity of the EGR gas that flows through the EGR conduit, the control apparatus comprising: a combustion stop control arrangement that executes a combustion stop control operation, which stops combustion in the internal combustion engine, when a predetermined combustion stop demand is generated; a cylinder-inflow EGR gas quantity determining arrangement that periodically computes cylinder-inflow EGR gas quantity information that indicates one of: a combustion stop delay control arrangement that executes a combustion stop delay control operation, which delays execution of the combustion stop control operation based on the cylinder-inflow EGR gas quantity information, wherein: the cylinder-inflow EGR gas quantity determining arrangement computes an EGR valve-passing gas flow quantity, which is a flow quantity of the EGR gas passing through the EGR valve, by using an EGR valve model that simulates a behavior of the EGR gas at a time that the EGR valve is open and the EGR gas is passing through the EGR valve in the EGR conduit; the cylinder-inflow EGR gas quantity determining arrangement computes the cylinder-inflow EGR gas quantity information based on the EGR valve-passing gas flow quantity by using an EGR gas delay model, which simulates a behavior of the EGR gas after the EGR valve is closed until a time of flowing into the cylinder by using data taken before the EGR valve is closed and reflects a delay in a flow of the EGR gas between the EGR valve and the cylinder; the combustion stop delay control arrangement periodically determines whether a current value of the cylinder-inflow EGR gas quantity information is larger than a threshold value that varies depending on an operational state of the internal combustion engine; when the combustion stop delay control arrangement determines that the current value of the cylinder-inflow EGR gas quantity information is larger than the threshold value, the combustion stop delay control arrangement disables the execution of the combustion stop control operation of the combustion stop control arrangement unless the combustion stop delay control arrangement receives a demand for immediately stopping the combustion of the internal combustion engine; and when the combustion stop delay control arrangement determines that the current value of the cylinder-inflow EGR gas quantity information is equal to or smaller than the threshold value, the combustion stop delay control arrangement enables the execution of the combustion stop control operation of the combustion stop control arrangement.