Exhaust gas re-circulation apparatus for internal combustion engine, has exhaust gas re-circulation valve to open or close passage of pipe, and exhaust gas re-circulation differential pressure is detected by differential pressure sensor

摘要

The exhaust gas re-circulation (EGR) apparatus has an EGR valve (42) for opening or closing a passage of an EGR pipe (41), and a differential pressure sensor (43) is provided to detect an EGR differential pressure. The differential pressure in the EGR pipe is between the pressure of the exhaust gas in upstream and downstream of the EGR valve. An EGR gas temperature, particularly a temperature of the exhaust gas in the EGR pipe, is detected by a temperature sensor (44). A target EGR flow rate is calculated by a calculating section. An independent claim is included for a characteristic detector for an exhaust gas re-circulation valve of the exhaust gas re-circulation device.