Patent ID: 7628136
Filing Date: 2009-12-08
Classification: F02D,Y02T

Abstract:
1. A method of controlling valves in an internal combustion engine for a vehicle in an all-cylinder activation mode of operation and a cylinder deactivation mode of operation, comprising: utilizing a variable valve timing system to continuously adjust engine valves during all-cylinder activation mode operation and during cylinder deactivation mode operation for increasing cylinder volumetric efficiency and reducing engine-pumping loss, thus improving fuel economy and performance; when in at least a portion of the all-cylinder activation mode of operation, selectively advancing each intake valve actuation phase at least about 8 crank angle degrees from a nominal operating domain comprised of a respective intake and exhaust valve centerline position setpoint for the internal combustion engine if it were lacking the variable valve timing system toward a fuel-economy operating domain comprised of a respective optimum intake and exhaust valve centerline position setpoint where there is improved fuel economy relative to any other of the intake and exhaust valve centerline positions for the internal combustion engine while the internal combustion engine is using variable valve timing during the all-cylinder activation mode of operation; concurrently, when in at least a portion of the all-cylinder activation mode of operation, selectively retarding each exhaust valve actuation phase at least about 6 crank angle degrees from the nominal operating domain toward the fuel-economy operating domain; transitioning from the all-cylinder activation mode of operation into the cylinder deactivation mode of operation when an intake valve centerline and an exhaust valve centerline are positioned within a range of centerlines centered on the nominal operating domain; when in the cylinder deactivation mode of operation, selectively advancing each active intake valve actuation phase within a range of about 0-10 crank angle degrees, inclusive, from the nominal operating domain toward the fuel-economy operating domain, and selectively retarding each active intake valve actuation phase within a range of about 0-10 crank angle degrees, inclusive, from the nominal operating domain toward an idle operating domain comprised of a respective valve centerline position setpoint when the engine is idling; and concurrently, when in the cylinder deactivation mode of operation, selectively retarding each active exhaust valve actuation phase within a range of about 0-12 crank angle degrees, inclusive, from the nominal operating domain toward the fuel-economy domain, and selectively advancing each active exhaust valve actuation phase within a range of about 0-12 crank angle degrees, inclusive, from the nominal operating domain toward the idle operating domain.