Patent ID: 6880517

Claim:
A two-step combustion system of an engine, wherein a fuel-air mixture is sucked into a combustion chamber by an operation of a suction valve driven by a cam for said suction valve mounted at an upper side of a cylinder head, and ignited by an ignition plug and burnt, the system comprising: an auxiliary combustion chamber formed at an upper lateral surface of a main combustion chamber to be recessed toward a cylinder head, wherein said fuel-air mixture of said combustion chamber is sucked into said auxiliary combustion chamber and only discharged from the auxiliary chamber into said main combustion chamber once combustion has commenced within said main chamber; a cam for an auxiliary combustion chamber valve formed on a suction valve cam shaft mounted at an upper side of said cylinder head and connected to a crankshaft of an engine via a belt to receive power for rotation; a rocker arm for being contacted at a first bottom distal end surface of said rocker arm with a surface of the cam for an auxiliary combustion chamber valve and swung about a fixed axle to thereby transfer power by way of leverage operation; and an auxiliary combustion chamber valve being contacted at a second bottom distal end surface of said rocker arm to vertically move and to open and close an inlet of said auxiliary combustion chamber.