Internal combustion engine control apparatus with ignition coil diagnosis function
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsWataru Fukui, Toshio Ohsawa
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Abstract
An engine control apparatus capable of detecting occurrence of abnormality in the ignition coil with high reliability. The apparatus includes an initial detection level hold device for holding an initial level (In) of a detected ion current value I, and an ignition coil diagnosis device for generating an abnormality decision signal of the ignition coil in dependence on the initial level of the ion current. By positively utilizing noise produced in an initial phase of the ignition cycle instead of eliminating it, the abnormality decision signal is generated, on the basis of which an appropriate engine protection measure is taken.
Claims6
A control apparatus for an internal combustion engine, comprising:
- angular position detecting means for generating a reference position signal corresponding to a predetermined crank angle of an engine cylinder in synchronism with the rotation of said engine;
- sensor means for acquiring running state information of said engine;
- an ignition coil having a primary winding and a secondary winding to which a spark plug of the associated engine cylinder is connected;
- ion current detecting means connected to the secondary winding of said ignition coil for detecting an ion current generated in said engine cylinder in each combustion cycle and outputting a corresponding ion current signal;
- control parameter setting means for setting a control parameter of said engine on the basis of said reference position signal and said engine running state information and correcting said control parameter on the basis of said detected ion current;
- detection level hold means for holding an initial level of said detected ion current signal;
- and
- ignition coil diagnosis means for generating an abnormality decision signal indicating occurrence of abnormality in said ignition coil on the basis of said initial level of said detected ion current signal;
- wherein said control parameter setting means validates a function for protecting said engine in dependence on the output signal of said ignition coil diagnosis means.
Dependencies are inferred from the claim text.