Variable valve timing mechanism for 3 cylinder and V6 engines

摘要

A 3 cylinder or V6 engine has first and second cylinders and a crankshaft with crank throws angularly spaced by 240‹. Inlet valves for the first and second cylinders are operated by respective first and second camshafts 18, 19, the second camshaft having an elongate portion 23 extending coaxially through the first camshaft. First and second variable valve timing (VVT) mechanisms 32, 33 comprise a common input member 41 having a pair of driving pegs 39, 57 which each engage in a slot in a respective intermediate driving member 36, 54. Each driving member in turn drives a respective output member 43, (59, fig. 6) on the respective camshaft by means of a corresponding peg and slot (38, 42 fig. 4 ad 56, 58 fig. 6). The axis of rotation of each intermediate driving member is movable by a eccentric sleeve 51 to vary the valve timing. The driving pegs are spaced by 120‹.