Patent ID: 6032630
Filing Date: 2000-03-07
Classification: F01L

Abstract:
A direct valve drive device comprising a cam, a cylinder head, a valve having a valve stem, a cap-shaped valve lifter having a closed top and axially slidably mounted between said cam and said valve stem slidably supported by said cylinder head, a valve spring supported by a spring seat for biasing said valve stem in such a direction that said valve lifter is pressed against said cam, said valve lifter being formed with a threaded hole coaxial with said valve stem, and an adjuster bolt threaded into said threaded hole and spring-biased so as to be movable, while rotating, toward said valve stem, an axial gap being formed between threadedly engaging portions of said valve lifter and said adjuster bolt, said axial gap being smaller than the height of a ramp formed on said cam but large enough to absorb any difference in thermal expansion between said cylinder head and said valve.