IDLE SPEED CONTROLLER FOR INTERNAL COMBUSTION ENGINE WITH VARIABLE VALVE TIMING MECHANISM

摘要

PROBLEM TO BE SOLVED: To prevent unstable rotation of an internal combustion engine at the time of idling, so as to prevent engine stall by conducting ISC corresponding to the number of failures in variable valve timing mechanisms (VVT) at the time of failure of the VVTs in the internal combustion engine. SOLUTION: The targeted rotational speed (S130) of an ISC and the opening of an ISCV (S135) when one VVT has abnormality in timing advance ('NO' at S110 or 'YES' at S120) are set larger (S140, S145) than those when all VVTs are normal ('NO' at S100 and S120), they are set further larger (S150, S155) when two VVTs have abnormality in timing advance ('YES' at S100 and S110). The number of the abnormal VVTs are reflected in the targeted rotational speed of the ISC and the opening of the ISCV, thus it is possible to prevent idle rotation from becoming unstable regardless of the number of the abnormal VVTs, and prevent engine stall effectively.