Patent ID: 7472685

Claim:
A control method of an internal combustion engine, for controlling an internal EGR rate by changing an opening timing and a closing timing of an intake valve and an exhaust valve to control an overlap period and a non-overlap period, said method comprising: controlling a throttle position of a throttle valve in accordance with an increase of a required amount of an engine output, in a first load range of the internal combustion engine which covers from a no-load to a load in one of a low-load range and a middle-load range, so as to open the throttle valve from an idle opening degree to one of a full opening degree and an almost full opened degree at the load; controlling the throttle position to one of the full opening degree and the almost full opened degree, in a second load range that is over the load; controlling the engine output by controlling the overlap period and the non-overlap period in accordance with the required amount, in an entire load range; and controlling the non-overlap period to obtain a maximum internal EGR rate from a maximum non-overlap period at the load.