Patent ID: 6691506
Filing Date: 2004-02-17
Classification: F01L,F02B,F02D,Y02T

Abstract:
A variable valve timing control device of an internal combustion engine comprising:an internal combustion engine equipped with an exhaust purifying catalyst, and an intake valve and an exhaust valve, the opening/closing timing of which are variably controlled; an engine cold determining unit that determines a cold state of the engine; an operating condition detecting unit that detects operating conditions including an engine load and an engine rotation speed; a reference valve timing setting unit that sets the reference valve timing of said intake valve and said exhaust valve based on the detected operating conditions; an air-fuel ratio setting unit that sets an air-fuel ratio based on the detected operating conditions; a cold state valve timing setting unit that sets the valve timing so that the opening timing of said exhaust valve is retarded with respect to said reference valve timing normally set during other engine states than the cold state, while reducing a valve overlap amount where the opening timing of said intake valve and said exhaust valve overlap with each other, when said air-fuel ratio is set to lean; and a valve timing adjusting mechanism that drives and adjusts said intake valve and said exhaust valve so that the valve timing of said intake valve and said exhaust valve reach the valve timing set by said cold state valve timing setting unit.