Patent ID: 8025043
Filing Date: 2011-09-27
Classification: F01L,F02D,Y02T

Abstract:
1. A controller for an internal combustion engine in which open/close characteristics of an engine valve of each of cylinders are continuously varied by operation of a variable valve timing mechanism so that the open/close characteristics are made suitable for engine operating conditions, and in which cylinder deactivation control is performed that switches, according to the engine operating conditions, the internal combustion engine between an all cylinder operation, in which all of the cylinders are operated, and a cylinder deactivation operation, in which operation of part of the cylinders is stopped, which the controller switches the variable valve timing mechanism between an operation allowed state and an operation inhibited state while the cylinder deactivation control is performed, wherein an engine operational region in which the cylinder deactivation operation is performed in the cylinder deactivation control is either a first engine operational region or a second engine operational region; the first engine operational region is determined provided that the open/close characteristics of the engine valve are varied so that the open/close characteristics are made suitable for the engine operating conditions when the variable valve timing mechanism is in the operation allowed state; the second engine operational region is determined provided that the open/close characteristics of the engine valve are fixed when the variable valve timing mechanism is in the operation inhibited state; wherein the second engine operational region in which the variable valve timing mechanism is in the operation inhibited state is narrower as compared to the first engine operational region in which the variable valve timing mechanism is in the operation allowed state.