Apparatus and method for controlling lean-burn engine of lean-burn engine

摘要

The control unit of the lean-burn engine is provided with an electronic control unit. The control unit of the lean-burn engine controls the engine rotation speed Ne and the throttle opening degree TPS at the start of transition from the theoretical operation to the lean operation, The basic opening degree DO of the idle speed control valve as the air bypass valve and the target gating pressure PO are obtained from the map and the driving pulses N corresponding to the basic opening degree DO are subjected to the idle rotation To the stepper motor (32) of the water control valve. Subsequently, a driving pulse corresponding to the opening correction amount D1 corresponding to the deviation between the target intake pressure PO and the actual intake pressure PB is transmitted to the stepper motor. As a result, the torque fluctuation at the time of switching between the lean burn operation and the rich operation involving the theoretical operation is suppressed.