Patent ID: 7331317
Filing Date: 2008-02-19
Classification: F01L,F01N,F02B,F02D,F02M,Y02T

Abstract:
1. A valve timing control system for an internal combustion engine comprising: a variable valve timing device that continuously variably controls valve closing timing of an intake valve relative to valve opening timing thereof; load detecting means for detecting load on the engine; valve-closing timing-determining means for determining the valve-closing timing of the intake valve according to the detected load on the engine; and control means for controlling the variable valve timing device according to the determined valve-closing timing of the intake valve, wherein said valve-closing timing-determining means determines the valve-closing timing of the intake valve such that the valve-closing timing of the intake valve is retarded with respect to the predetermined timing in which an expansion ratio becomes equal to a compression ratio in a combustion cycle of the engine, when the load on the engine is in a first predetermined load region, and determines the valve-closing timing of the intake valve such that the valve-closing timing of the intake valve is advanced with respect to the predetermined timing, when the load on the engine is in a second predetermined load region higher than the first predetermined load region.