| 摘要 |
PROBLEM TO BE SOLVED: To avoid increase in emission and deteriorating of drivability by lagging a phase of an ignition timing when the voltage of a battery is slower than a prescribed value in an operating region for carrying out multiple ignitions, in a device where the multiple ignitions are carried out according to the operating region. SOLUTION: In a stratified burning operating condition, the timing when the vicinity of an ignition plug 50 is covered with a mixture of combustible concentration is limited, and the timing is fluctuated between cycles, and thereby multiple ignitions are necessitated. In multiple ignitions, a plurality of sparks are generated by turning off/on an ignition signal by plural times (for example three times). In this case, when voltage of a battery 56 is reduced, a rise time of a current which flows in a primary wire 53a of an ignition coil 53 is delayed as compared to a regular time. It takes a long time to accumulate energy in the ignition coil, ignitionability of ignition after two times. Therefore, a phase of an ignition timing is lagged, when voltage of the battery is reduced to improve ignitionability of mixture.
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