Electromagnetic valve drive apparatus of internal combustion engine

摘要

An electromagnetic valve drive apparatus of an internal combustion engine has a three-switching element in-series type drive circuit. Through switching operations of switching elements that are shared by eight electromagnetic coils consisting of upper coils and lower coils of four valves. The four valves include a first two valves that perform identical operations and a second two valves whose open period does not overlap the open period of the first two valves. The three-switching element in-series type drive circuit is able to supply current and to rapidly reduce, or discontinue, current through the electromagnetic coils. The electromagnetic valve drive apparatus is able to control the quantity of current through the electromagnetic coils while reducing the number of switching elements employed.