Multi valve engine
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorMasaaki Yoshikawa
Life of this patent
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Abstract
A unitary cylinder head assembly for a five-valve per cylinder internal combustion engine. The cylinder head assembly has upstanding walls that form tappet receiving bores for receiving the tappets that operate the respective valves. In addition, these walls provide bearing surfaces for a pair of camshafts, one of which actuates one set of valves and the other of which actuates another set of valves. The threaded fastening means for affixing the cylinder head to the cylinder block are disposed axially beyond the walls and in the case of the set containing the greater number of valves transversely outwardly from the walls. However, the threaded fastening means are disposed so that they are equal distance from the associated cylinder bore axis.
Claims22
A cylinder head assembly for an internal combustion engine, comprising a lower surface adapted to sealingly engage a cylinder block around a cylinder bore, a first series of three poppet valves supported for reciprocation within said cylinder head on substantially one side of a plane containing the axis of the cylinder bore, a second series of at least two poppet valves supported for reciprocation in said cylinder head substantially on the other side of said plane, a first camshaft rotatably journaled by a cylindrical portion thereof in said cylinder head and operating said first set of valves, a second camshaft rotatably journaled by said cylinder head and operating said second set of valves, a first pair of threaded fastening means disposed on said other side of said plane and substantially at the same distance therefrom as the rotational axis of said second camshaft for affixing said cylinder head to the associated cylinder block, and a second pair of threaded fastening means on said one side of said plane and having their axes spaced further from said plane than the outer periphery of the cylindrical portion of said first camshaft for affixing said cylinder head to the associated cylinder block.
A cylinder head assembly for an internal combustion engine and having a lower surface for sealingly engaging a cylinder block around a cylinder bore therein, a first series of three poppet valves supported for reciprocation within said cylinder head substantially on one side of a plane containing the axis of the cylinder bore, a second set of at least two poppet valves supported for reciprocation within said cylinder head on the other side of said plane, a first camshaft rotatably journaled on bearing surfaces formed in said cylinder head on said one side of said plane and over said cylinder bore for operating said first set of poppet valves, a second camshaft rotatably journaled in bearing surfaces of said cylinder head on the other side of said plane for operating said second set of valves, bearing cap means affixed to said cylinder head over said cylinder bore for rotatably journaling said camshafts, and two pairs of threaded fastening means, each pair being disposed on a respective side of said plane, for affixing said cylinder head to the associated cylinder block, the pairs of threaded fastening means being disposed outwardly from said bearing caps along the longitudinal direction of said plane.
Dependencies are inferred from the claim text.