CLOSED BREATHER DISCONNECTION DETECTION METHOD

摘要

Disclosed is a method for detecting disconnection of a closed breather 18 separating and recovering oil mist from blow-by gas 17 extracted from an engine 1 to return the blow-by gas through a gas return pipe 19 to an intake pipe 5. Under condition of no exhaust gas 9 recirculation being conducted, a mass flow rate of in-cylinder working gas is calculated based on a boost pressure, an intake temperature of an intake manifold 7 and a rotational frequency of the engine, and whether the calculated mass flow rate is divergent from a value detected by an air flow sensor 24 is determined. When determined to be divergent, the divergence in a last determination is compared with a current divergence; if difference between the divergences is beyond a predetermined range, the gas return pipe 19 is determined to be in disconnection from the intake pipe 5.

主权项

1. A method for detecting disconnection of a closed breather which separates and recovers oil mist from blow-by gas extracted from an engine to return the blow-by gas through a gas return pipe to an intake pipe, which comprises calculating a mass flow rate of in-cylinder working gas on the basis of a boost pressure, an intake temperature in an intake manifold and a rotational frequency of the engine under a condition of no exhaust gas recirculation being conducted, determining whether the calculated mass flow rate is divergent from a value detected by an air flow sensor or not, comparing a divergence in a last determination and a current divergence when determined to be divergent, and determining disconnection of the gas return pipe from the intake pipe when a difference between both the divergences is great beyond a predetermined range.