Method and system of improving engine braking by variable valve actuation

摘要

The present invention relates to methods of improving engine braking of a reciprocating piston internal combustion engine by variable valve actuation. One embodiment of the present invention enables independent two-valve actuation for each cylinder, and engine braking horsepower can be optimized using two-valve braking at high engine speeds and one-valve braking at low speeds. Another embodiment of the present invention enables better a sequential valve actuation to reduce engine braking load and compliance. Another embodiment of the present invention enables better engine starting and warming up by controlling timing and lift of each valve.