Variable valve drive mechanism for an internal combustion engine
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorMasahiro Uchida
Life of this patent
Estimating the term…
Abstract
An improved arrangement for controlling the valve operation of an internal combustion engine wherein the control valves are mounted within perpendicularly extending bores formed in the cylinder head and camshaft bearing cap with the bores being deep enough so that the valves do not project significantly beyond the cylinder head. In addition, one or more of the connecting passages are formed by grooves in the mating surfaces of the cylinder head and bearing cap to avoid the necessity of drillings and particularly of drilling blind bores.
Claims21
An internal combustion engine comprised of a cylinder head member adapted to be affixed in closing relation with at least one cylinder bore to form a variable volume combustion chamber with a piston reciprocating in said cylinder bore, at least one valve supported for reciprocation in said cylinder head for serving said combustion chamber, a camshaft journalled in said cylinder head and a cam bearing cap affixed to said cylinder head for operating said valve, a hydraulically operated variable valve actuating mechanism for actuating said valve from said cam shaft, a control valve for selectively controlling the operation of said hydraulically operated variable valve actuating mechanism, said control valve having a spool portion and an operating portion for effecting reciprocation of said spool portion, a fitting opening extending through said cam bearing cap and aligned with a corresponding fitting opening in said cylinder head member, said fitting openings having their axes extending perpendicularly to facing and abutting surfaces of said cam bearing cap and said cylinder head, said control valve being disposed in substantial part in said fitting openings.
An internal combustion engine comprised of a cylinder head member adapted to be affixed in closing relation with at least one cylinder bore to form a variable volume combustion chamber with a piston reciprocating in said cylinder bore, at least one valve supported for reciprocation in said cylinder head for serving said combustion chamber, a camshaft journalled in said cylinder head and a cam cap affixed to said cylinder head for operating said valve, a hydraulically operated variable valve actuating mechanism for operating said valve from said cam shaft, a control valve for selectively controlling the operation of said hydraulically operated variable valve actuating mechanism, said control valve having a spool portion and an operating portion for effecting reciprocation of said spool portion, said control valve supplies fluid to and exhausts fluid from said variable valve timing mechanism through a plurality of passages formed in said internal combustion engine, at least one of these passages is formed by a recess formed in facing and abutting surfaces of said cam cap and said cylinder head.
Dependencies are inferred from the claim text.