| 摘要 |
A basic target compression ratio calculating unit (21) finds a basic target compression ratio (btCR) from a demand load (tT) and an engine speed (Ne). When component temperatures (Tem, Tes), which are calculated by a component temperature calculating unit (23) from the exhaust temperature (Texh) detected by an exhaust temperature sensor (8), are higher than respective threshold values, a basic target air-fuel ratio (btAF) is corrected by a target air-fuel ratio correcting unit (24) and the amount of fuel is increased. Thus, because knocking does not occur easily, at the same time a target compression ratio (tCR) is corrected to the high pressure ratio side. Because the exhaust temperature decreases due to thermal efficiency being improved by a high compression ratio, the exhaust temperature can be reduced by a relatively small increase in the amount of fuel. |
