Combustion chamber structure in an internal combustion engine.

摘要

A combustion chamber structure in a direct injection internal combustion engine, in which the exhaust valve (28) is provided over the upper surface of the piston (12) and partially overlaps a cavity (14) in the upper surface of the piston (12) in order to provide a good air utilization factor in the combustion chamber, and a superior combustion efficiency. The exhaust valve (28) also may be positioned so as to form an auxiliary combustion chamber (30). A recess (24) may be formed in an upper position of the piston (12) facing the exhaust valve (28).