Patent ID: 6904881
Filing Date: 2005-06-14
Classification: F01L,F02D,Y02T

Abstract:
1. A control apparatus for an internal combustion engine, the engine having an intake valve and an exhaust valve, the apparatus comprising: a variable valve actuation mechanism of a fluid pressure operated type, wherein the variable valve actuation mechanism changes a valve overlap amount of the valve opening period of the intake valve and the valve opening period of the exhaust valve according to the operating state of the engine; a lock mechanism that selectively switches the variable valve actuation mechanism to a locked state and an unlocked state by using fluid pressure supplied to the variable valve actuation mechanism; and a controller that restricts an operation amount of the variable valve actuation mechanism such that increase in the valve overlap amount is restrained when the engine is in a transient operation state in which the output of the engine increases, wherein the controller judges whether the variable valve actuation mechanism is in the locked state, and if the controller determines that the variable valve actuation mechanism is in the locked state, the controller relaxes the restriction imposed on the operation amount of the variable valve actuation mechanism.