Patent ID: 6502563
Filing Date: 2003-01-07
Classification: F02B,F02D,F02M,Y02T

Abstract:
A control device for an engine (1), the engine comprising a combustion chamber (1A), an intake passage (3) which aspirates air into the combustion chamber (3A), an exhaust passage (2) which discharges exhaust gas from the combustion chamber (3A), and an exhaust gas recirculation valve (6) which recirculates part of the exhaust gas of the exhaust passage (2) into the combustion chamber (1A), the device comprising:a sensor (34, 39) which detects a running condition of the engine (1); and a microprocessor (41) programmed to: set a target exhaust gas recirculation amount based on the running condition (S25, S26); determine a maximum recirculation amount of the exhaust gas recirculation valve (6) (S27); compare the target exhaust gas recirculation amount with the maximum recirculation amount (S28); limit the target exhaust gas recirculation amount to be equal to the maximum recirculation amount when the target exhaust gas recirculation amount exceeds the maximum recirculation amount (S28); control the opening of the exhaust gas recirculation valve (6) based on the target exhaust gas recirculation amount (S29); and maintain the opening of the exhaust gas recirculation valve (6) at an opening corresponding to the maximum recirculation amount for a predetermined time after the target exhaust gas recirculation amount has fallen below the maximum recirculation amount (S26).