Combustion chamber for an internal combustion engine of direct injection type

摘要

A combustion chamber for an internal combustion engine of the direct injection type defined by a cylinder head, a cylinder liner and a piston head, the piston head having formed therein a cavity in which air swirl can be produced by a known means. A fuel injection valve having a plurality of fuel injection nozzles is disposed above the cavity for injecting jets of fuel radially against the cavity wall. The cavity comprises an equilateral polygonal cavity formed in the upper part of the piston head and a toroidal cavity formed continuously to the polygonal cavity in the lower part of the piston head. The equilateral polygonal cavity has rounded corners formed therein, the ratio of the radius of the rounded corners to that of a inscribed circle of the equilateral polygonal cavity being from about 0.05 to about 0.8.