| 摘要 |
PROBLEM TO BE SOLVED: To enable a disconnection of gas return pipe of a closed breather to be accurately judged.SOLUTION: This invention relates to a method for detecting a disconnection of a closed breather 18 in which blow-by gas 17 is removed from an engine 1 and returned back to an intake pipe 5 through a gas return pipe 19 after oil mist is separated and recovered. A mass flow rate of in-cylinder working gas is calculated under a condition in which a recirculation of exhaust gas 9 is not carried out on the basis of a boost pressure, an intake temperature of an intake manifold 7 and the number of rotation of an engine, it is judged whether or not the calculated value of the mass flow rate is different from a detected value of an air flow sensor 24. In the case that it is judged that the difference state is present, a difference at the previous judgment and the present difference are compared to each other and if a varying amount of both differences exceeds a prescribed range, it is judged that the gas return pipe 19 is removed from the intake pipe 5 and is kept in disconnected state. |
