| 摘要 |
PROBLEM TO BE SOLVED: To improve a responsibility of boost pressure in a lean region by controlling a valve timing of an exhaust valve at a lean-burn engine having a turbosupercharger while restricting variation of combustion state.SOLUTION: In order to execute controlling of increasing in supercharger pressure by operating a variable valve mechanism and advancing an angle of an opening time while keeping a closing time constant if a target operating point is present in a lean region and an actual supercharging pressure is lower than a target supercharger pressure at a lean-burn engine having the variable valve mechanism in which an opening time can be changed while a closing time of an exhaust valve is kept constant.SELECTED DRAWING: Figure 10 |
