EGR FLOW RATE CALCULATING DEVICE OF INTERNAL COMBUSTION ENGINE AND CONTROL DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an EGR flow rate calculating device of an internal combustion engine for accurately calculating an EGR flow rate by properly and directly correcting the EGR flow rate on the basis of a precise analytical result of influence by an atmospheric pressure change. SOLUTION: While compensating for a flow speed change caused by the atmospheric pressure change by calculating an EGR flow speed Q under standard atmospheric pressure PO from a map on the basis of suction negative pressure Pb, the pressure ratio Pb/Pa of atmospheric pressure Pa and an engine speed Ne, the EGR flow rate▵Pr(n) is calculated by compensating for a density change caused by the atmospheric pressure change by correcting a basic EGR flow rate▵PrO(n) determined from this EGR flow speed Q and the EGR opening area S by a density correction factor Pa/PO being the ratio of the atmospheric pressure Pa to the standard atmospheric pressure PO. COPYRIGHT: (C)2004,JPO