| 摘要 |
In order to prevent an abnormal combustion due to oil, a restriction region (B) is designated on a low-speed and high-load side of an internal combustion engine (1), and an opening of throttle valve (12) is restricted so that an engine operating condition is not observed within the restriction region (B). A predetermined designated inspection region (A) is set so as to include the restriction region (B), and it is judged whether or not the abnormal combustion actually occurred when the internal combustion engine (1) is running within the designated inspection region (A). If the abnormal combustion was detected, the restriction region (B) is expanded, meanwhile, if the abnormal combustion was not detected, the expanded restriction region (B) is gradually decreased. If the abnormal combustion occurred at a shorter interval than a threshold value, it is determined that an abnormality such as oil deterioration occurred, and the restriction region (B) is expanded at once to a predetermined size and a warning means (26) is actuated. |
