EXHAUST GAS RECIRCULATION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

An exhaust gas recirculation device for an internal combustion engine is characterized by being provided with an opening degree command signal output means (52) for outputting an opening degree command signal for an EGR control valve on the basis of the operating state of the internal combustion engine, a fluctuation component separation means (54) for separating the valve opening degree command signal from the opening degree command signal output means (52) into a basic component and a fluctuation component generated by being superposed on the basic component, a fluctuation component determination means (56) for determining whether the EGR control valve is in a stationary state or a transient state on the basis of the magnitude of the fluctuation component separated by the fluctuation component separation means (54), and an EGR control valve diagnosis unit (58) for diagnosing the abnormality of the EGR control valve when the fluctuation component determination means determines that the EGR control valve is in the stationary state.