Exhaust pressure estimation device for internal combustion engine and internal EGR amount estimation device using the same

摘要

PPROBLEM TO BE SOLVED: To easily determine the exhaust pressure PEX near an exhaust valve. PSOLUTION: An exhaust gas mass flow rate MFEXG and an exhaust gas constant REX are calculated on the basis of respective parameters relating to an operating state of an internal combustion engine (engine rotating speed NRPM, basic fuel injection amount TP, target combustion equivalent ratio TFBYA and the like) (steps 1, 2), an exhaust gas temperature TEVC is detected (step 3), the pressure loss terms relating to laminar flow and eddy flow are calculated on the basis of these values, and an exhaust pressure square value PEXSQ is calculated on the basis of the pressure loss terms and the atmospheric pressure PPAMB (step 4). Then the exhaust pressure PEX near the exhaust valve is calculated on the basis of its square root (step 5). PCOPYRIGHT: (C)2005,JPO&NCIPI