| 摘要 |
PURPOSE:To decrease an exhaust temperature so as to be held to the allowable a limited exhaust temperature or less by providing an EGR control means for enhancing the EGR ratio when the exhaust temperature rises to the prescribed allowable limited exhaust temperature due to an increase in the engine speed. CONSTITUTION:The fuel injection amounts of first and second fuel injection valves 5a, 5b of respective cylinders 1 to 6 are respectively controlled by a control unit 10. In an engine VE, the control unit 10 suitable controls the opening/closing timing of intake valves 1a, 1b, the EGR ratio, the pressurized air relief amount and the air-fuel ratio on the basis of the engine speed, the S/C discharge temperature and the exhaust temperature, so as to prevent knocking from being generated in all driving range. Thereby, when the exhaust temperature is raised to the fixed allowable limited exhaust temperature due to an increase in the engine speed during its operation, the EGR ratio is enhanced by enlarging the opening of the second EGR valve 42, and the exhaust temperature is lowered so as to be held to the allowable limited exhaust temperature or less. |
