Patent ID: 6792924
Filing Date: 2004-09-21
Classification: F01L,F02B,F02D,F02M,Y02T

Abstract:
An engine control system for an internal combustion engine comprising:a variable compression ratio mechanism comprising a multi-link type piston-crank mechanism having a plurality of links and enabling a compression ratio of the engine to be varied by changing a piston stroke characteristic by way of a change in an attitude of a part of the links; an exhaust-gas recirculation system enabling at least one of external EGR and internal EGR to be controlled; the links of the multi-link type piston-crank mechanism being laid out, so that a piston velocity near top dead center, obtained by the multi-link type piston-crank mechanism, is slower than a piston velocity near top dead center, obtained by a single-link type piston-crank mechanism having at least the same piston stroke as the multi-link type piston-crank mechanism; during a part load condition of the engine, the variable compression ratio mechanism controlling the compression ratio to a predetermined high compression ratio; and during the part load condition, the exhaust-gas recirculation system increasing exhaust-gas recirculation.