| 摘要 |
The present invention aims at preventing such a situation that anyone of the divided injection amounts becomes less than a minimum compensation amount for a fuel injection valve, in case of conducting a two-step injection (weakly stratified combustion) in which a part of fuel is injected during intake stroke and the remaining fuel is injected during compression stroke. To this end, at the time of instructing to conduct the two-step injection, a whole injection amount TI is divided into: an injection amount TIH for homogeneous combustion to be injected during intake stroke, and an injection amount TIS for stratified combustion to be injected during compression stroke, based on a division ratio corresponding to a target air-fuel ratio. Further, each of the injection amounts TIH and TIS after division is compared with a minimum compensation amount MIN for the fuel injection valve. Based on the result of the comparison, the injection amount, which has a smaller division ratio, is set to be zero, and the injection amount, which has a larger division ratio, is set to be the whole injection amount TI, when either one of the injection amounts TIH and TIS is judged to be less than the minimum compensation amount MIN. Alternatively, the injection amount, which has the smaller division ratio, is set to be the minimum compensation amount MIN, and the injection amount, which has the larger division ratio, is set to be the remainder obtained by subtracting the minimum compensation amount MIN from the whole injection amount TI.
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