Patent ID: 9726093
Date: 2017-08-08
CPC Classifications: F02D,F02M,Y02T

Claim:
1. An apparatus for estimating exhaust gas recirculation quantity of an internal combustion engine provided with an EGR valve which adjusts a quantity of an exhaust gas recirculating from an exhaust passage to an intake passage upstream of an throttle valve through an EGR passage, the apparatus comprising: a computing portion for computing a quantity of the exhaust gas passing through the EGR valve by means of an EGR valve model which simulates a behavior of a recirculated exhaust gas passing through the EGR valve in the EGR passage; a computing portion for computing a quantity of the exhaust gas flowing into a cylinder based on the quantity of the exhaust gas passing through the EGR valve, by means of an EGR-gas-delay model which simulates a behavior of the exhaust gas passing through the EGR valve and the throttle valve and flows into a cylinder; a total gas-quantity computing portion for computing a total quantity of passing through the throttle valve by means of an throttle model which simulates a behavior of a gas passing through the throttle valve in the intake passage; an intake air flow rate obtaining portion for detecting or estimating a fresh air quantity flowing through the intake passage; and a correction portion for correcting a computed total-gas-quantity passing through the throttle valve based on the fresh air quantity detected or estimated by the intake air flow rate obtaining portion; wherein the EGR valve model is defined by a map which defines a relationship between an opening degree of the EGR valve, the total gas quantity passing through the throttle valve and the exhaust gas quantity passing through the EGR valve.