Variable cycle internal combustion engine and controller thereof

摘要

A two-cycle action cam having two protruding parts 1a and 1b and a four-cycle action cam 3 having one protruding part 3a are selectively used by a cam change mechanism 46i. The two-cycle action cam 1 effects opening of the inlet and exhaust valves once per revolution of the crankshaft and the four-cycle action cam 3 effects opening of the inlet and exhaust valves once per two revolutions of the crankshaft. The four-cycle action is selected when the engine is in the low revolving speed and running at a low load and the two-cycle action is otherwise selected.