US 6,672,276 B2 · Direct fuel injection engine

Abstract

A direct fuel injection engine has a fuel injection valve that injects fuel toward a cavity formed in a top of a piston, and a spark plug that ignites the fuel-air mixture resulting from the fuel injection. The direct fuel injection engine is configured to strengthen the penetration of the fuel streams, to improve the directionality of the fuel streams and to stably form an agglomerate fuel-air mixture close to the spark plug. The cavity preferably has a bottom surface, a curved surface, and a flat surface. In a plan view taken along the center axis of the engine cylinder, cavity C is shaped like an ellipse whose foci are located at the tip of fuel injection valve and the spark discharge gap of spark plug, respectively. The fuel injection valve has a plurality of injection vents that spray solid-core fuel streams.

Claims17

Dependent claims

A direct fuel injection engine comprising:

a combustion chamber having a piston movably mounted therein, the piston including an upper wall having a cavity with a fuel stream directing surface;
a spark plug having a spark discharge gap arranged to ignite a fuel-air mixture in the combustion chamber;
and
a fuel injection valve including a front edge portion with a plurality of injection vents arranged and configured to directly inject fuel into the combustion chamber against the fuel stream directing surface as plurality of solid-core fuel streams that strike at non-perpendicular angles,
the fuel stream directing surface being at least partially curved to direct movement of the fuel streams after striking the fuel stream directing surface toward the fuel injection valve, and the fuel stream directing surface being partially elliptical in a top plan view with its focal points being located at the front edge portion of the fuel injection valve and at the spark discharge gap of the spark plug as its focal points.

2 more elements

Dependencies are inferred from the claim text.

Direct fuel injection engine

Life of this patent

Direct fuel injection engine

Life of this patent

Abstract

Claims17