Direct fuel injection-type spark-ignition internal combustion engine

摘要

A direct fuel injection-type spark-ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed on the top surface of the piston, and a fuel injection valve for injecting fuel into the cavity in nearly the flat fan shape having a relatively small thickness. An opposing side wall of the cavity opposite to the fuel injection valve, for leading the fuel to the vicinity of the spark plug, has an arcuate portion having a plurality of arcuate shapes in a plan view. The radius of arcuate shape at the both side parts of the arcuate portion in a plan view is smaller than the radius of arcuate shape at the center part of the arcuate portion in a plan view. The opposing side wall has a deflecting portion to deflect the fuel toward the inside of the cavity. <IMAGE>