Patent ID: 7987833

Claim:
A combustion system for a vehicle, comprising: a piston in which a first combustion recess is formed in an upper end surface thereof, and at least one second combustion recess is further formed in a bottom surface of the first combustion recess; a first intake port and a second intake port for supplying a cylinder with air; and a controller that separately controls amounts of a recirculation exhaust gas being supplied to the first intake port and the second intake port so that EGR gas concentration of the air drawn into the cylinder through the first and second intake ports become different; wherein the first combustion recess has a first depth from the upper end surface of the piston and the second combustion recess has a second depth that is deeper than the first depth from the upper end surface of the piston; and wherein an exhaust gas dense portion is formed in one side among the first combustion recess and the second combustion recess, and an oxygen dense portion is formed in the other side thereof to provide a stratification of the exhaust gas simultaneously formed in a radial direction as well as in an up/down direction of the cylinder.