| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily detect abnormality due to a nozzle stick, by providing EGR detecting means by which the actual value of an EGR rate is detected, and judging such a state that a turbo charger is abnormal when an EGR actual value detected by the EGR detecting means is shifted more than a predetermined value from a target value. SOLUTION: In a controller 10 to which output signals from an air flow meter 21, an intake pipe pressure sensor 22 and an intake pipe temperature sensor 23 are inputted, firstly, 'an intake air flow + an EGR gas flow' is calculated on the basis of intake pipe pressure and intake pipe temperature, and subsequently, an actual EGR rate is calculated. Next, a ratio of a target EGR rate separately calculated to the actual EGR rate, is found out, and an EGR rate shearing exponent is calculated. Then, it is judged whether or not this EGR rate shearing exponent is within a normal range, and in the case that a first nozzle stick is detected when judgment is NO, a warning is issued. Also, a maximum fuel ejection rate in a high speed position is decreased for the purpose of protecting an engine.</p> |
