Direct injection gasoline engine with stratified charge combustion and homogeneous charge combustion

Abstract

An internal combustion gasoline engine has an air intake assembly which introduces air through the cylinder head into the cylinder to generate swirl (horizontal vortex) flow (as opposed to tumble (vertical vortex) flow) for stratified charge combustion, and to generate tumble flow for homogeneous charge combustion. The piston includes a cavity combustion chamber at the top surface of the piston, the cavity combustion chamber having a round shape and an increasing cross sectional area as the top of the piston is approached. During stratified charge combustion, swirl flow is smoothly guided into the cavity combustion chamber and preserved with a sufficient intensity since the cavity combustion chamber is well sealed at its whole periphery. During homogeneous charge combustion, a tumble flow is formed inside the cylinder, and fuel injection is made in the intake stroke. Fuel supplied into the cavity combustion chamber is easily washed away by the tumble stream. Valve recesses may also be provided at the top of the piston.

Dependencies are inferred from the claim text.