Patent ID: 7165526

Claim:
A direct injection engine comprising: a combustion chamber defined between a cylinder head and a piston; an intake valve and an exhaust valve both disposed in said cylinder head; an ignition plug disposed to face said combustion chamber; a fuel injection valve disposed at a predetermined angle relative to a horizontal plane in said combustion chamber, which is perpendicular to the direction of upward/downward movement of said piston, and directly injecting fuel into said combustion chamber; a cavity formed in a crown surface of said piston such that fuel spray injected from said fuel injection valve is blown into said cavity; and obstacle means provided in said cavity and decelerating or stopping the fuel spray blown into said cavity, thereby performing super-retard combustion under high backpressure; wherein the height or depth of said obstacle means is set to be within the range of 1–5% in terms of ratio with respect to a cylinder bore.