Patent ID: 6178936
Filing Date: 2001-01-30
Classification: F01L,F02B,F02F

Abstract:
An overhead-valve internal combustion engine, comprising:a hemispherical or pent roof cylinder head which has a combustion chamber formed with a curved top portion projecting upward;an intake valve and an exhaust valve mounted symmetrically with respect to an axis of a cylinder;a rocker arm supporting base fixed on a mounting surface of said cylinder head;rocker arm shafts supported by said rocker arm supporting base;rocker arms engaged with said rocker arm shafts at central portions of said rocker arms in such a way that said rocker arms are free to swing, and engaged with push rods which push said intake and exhaust valves; anda head cover to cover a valve operating mechanism formed by said intake and exhaust valves, said rocker arm supporting base, and said rocker arms, said head cover being fixed on a top surface of said cylinder head,wherein the intake valve and the exhaust valve are inclined when mounted symmetrically with respect to the axis of the cylinder so as to extend out towards the top surface of the cylinder head,wherein said mounting surface is formed on a central portion of said top surface and is positioned between the intake valve and the exhaust valve,wherein said mounting surface is virtually coplanar with said top surface on which said head cover is fixed, andwherein said rocker arm shafts and said rocker arms are first mounted on said rocker arm supporting base, and said rocker arm supporting base is then fixed on said cylinder head.