Valve driving apparatus using an electromagnetic coil to move a valve body with reduced noise

摘要

An electromagnetic force generated in a valve driving apparatus is rapidly decreased when a valve body moves to a position close to the end of its stroke so that a shock generated when the valve body reaches the end of the stroke is reduced. The valve body is movable between opposite ends of its stroke so as to open and close a valve provided in an internal combustion engine. An electromagnetic coil generates an electromagnetic force exerted on the valve body. A current supplied to the electromagnetic coil is controlled in accordance with an operational condition of the internal combustion engine. The current flowing in the electromagnetic coil is rapidly decreased when the valve body approaches the end of its stroke.