FAILSAFE CONTROL SYSTEM AND METHOD FOR AN ELECTROMAGNETICALLY DRIVEN VALVE

摘要

A failsafe control system for a valve electromagnetically driven for opening and closing an intake port or exhaust port of an internal combustion engine is provided. The valve is of the type which is held in a neural position, i.e., in a partly open position when an electromagnetic actuator is not energized. When the valve fails in opening, the supply current is increased than that at normal times to drive the valve to close, whereby to prevent misfire, backfire and a bad influence to intake conditions of other cylinders and thereby attain an elongated service life of engine parts. A failsafe control method is also provided.