VARIABLE VALVE TIMING CONTROL DEVICE FOR ENGINE

摘要

PROBLEM TO BE SOLVED: To suppress the amount of HC discharged from an engine by a variable valve timing control device for an engine. SOLUTION: The variable valve timing control device is capable of changing opening/closing timing of each of an intake valve 4 and an exhaust valve 5 of the engine 3. The device is structured to switch between two modes: a first operation mode set to have the intake valve 4 open after the exhaust valve 5 is closed and the closing timing of the exhaust valve 5 set to be before combustion top dead center; and a second operation mode advancing the opening timing of the intake valve 4 to before the combustion top dead center in regard to the first operation mode. The device is structured so that at start of the engine 3, the operation mode of the intake valve 4 and the exhaust valve 5 is set to the first operation mode, and then, after first predetermined conditions are satisfied, the mode is switched to the second. COPYRIGHT: (C)2005,JPO&NCIPI