| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress abnormal combustion in middle and high rotation areas (I) with supercharging pressure increased and also to ensure engine output in a low rotation area (II) where the supercharging pressure tends to become insufficient, in an engine 1 including a supercharger 20 supercharging intake air and an intercooler 12 cooling the supercharged intake air. <P>SOLUTION: In the middle and high rotation areas (I) where a desired supercharging effect is expected, the intake air is cooled by the intercooler 12 to suppress an intake air temperature rise while increasing intake air filling efficiency by supercharging, and further, an effective compression ratio is reduced by a Miller cycle, thereby providing sufficient high output while suppressing the abnormal combustion. Since the abnormal combustion is suppressed, even in the supercharged engine 1, it is not necessary to set a geometrical compression ratio to a lower level as done in the past. Thereby, the engine output is ensured by achieving the relatively high effective compression ratio without performing the Miller cycle in the low rotation area (II) where a supercharging effect is not sufficiently expected. <P>COPYRIGHT: (C)2011,JPO&INPIT |
