| 摘要 |
PURPOSE:To minimize the amount of HC and NOx discharged together with exhaust gas of a diesel engine, by detecting the amount of fuel, the total amount of gas and the excess air factor, and controlling the amount of exhaust gas to be recirculated such that the amount of fuel, the total amount of gas and the excess air factor thus detected satisfy a prescribed relationship. CONSTITUTION:By putting the amount F of fuel, the absolute pressure P in an intake pipe and the density (O2) of oxygen contained in the exhaust gas into a computer 5, the excess air factor lambda is calculated from an equation, lambda=A- B.F/{G'.(P/P0)}, where A, B are constants individual to each engine, G' is the total amount of gas under the normal pressure, and P0 is the absolute pressure in the intake pipe under the normal pressure. Further, the actual excess air factor lambda(O2) is calculated from the density (O2) of oxygen contained in the exhaust gas, and comparison is made between lambda and lambda(O2). In case of lambda<lambda(O2), the magnetic field produced by a solenoid 65 of a vacuum control valve 6 is intensified, while in case of lambda<lambda(O2), the output vacuum is lowered. |
