Patent ID: 6513467
Filing Date: 2003-02-04
Classification: F01L,Y10T

Abstract:
A variable valve control device of an internal combustion engine having intake and exhaust valves, comprising:an IVWAV mechanism which varies a working angle of the intake valve; an IVOPV mechanism which varies an operation phase of the intake valve; an EVOPV mechanism which varies an operation phase of the exhaust valve; and a control unit which controls said IVWAV, IVOPV and EVOPV mechanisms in accordance with an operation condition of the engine, said control unit being configured to carry out; controlling, in a middle-load operation range of the engine, said IVWAV, IVOPV and EVOPV mechanisms to achieve a valve overlap wherein near the top dead center (TDC) on the intake stroke, there is a certain period when both the intake and exhaust valves assume their open conditions, and in case of shifting of the engine from the middle-load operation range to a very low-load operation range, controlling said IVWAV mechanism to reduce the working angle of said intake valve thereby to retard the open timing of said intake valve and controlling said EVOPV mechanism to advance the operation phase of said exhaust valve thereby to advance the close timing of said exhaust valve.