Intake air control system of engine

摘要

A control unit controls both a motor actuated throttle valve and a magnetically actuated variable valve in accordance with an operation condition of an internal combustion engine. The control unit is configured to provide both a first control mode wherein an intake air control is carried out by controlling the open/close timing of the variable valve while keeping the throttle valve at a full-open or near full-open position and a second control mode wherein the intake air control is carried out by controlling the position of the throttle valve while reducing a controllable range of the open/close timing of the variable valve. The first and second control modes are selectively switched in accordance with the operation condition of the engine. The first and second control modes allow the engine to output the same engine torque under the same operation condition of the engine. The first and second control modes are respectively provided by calculating target intake air amounts for the first and second control modes and feeding the engine with the calculated target intake air amounts respectively.