Combustion chamber of an internal combustion engine

摘要

Disclosed is an internal combustion engine comprising a cylinder head and a piston. A recess is formed on the inner wall of the cylinder head or on the top surface of the piston. The recess defines a combustion chamber when the piston reaches the top dead center. The inner wall of the cylinder head has a flat surface portion. The top surface of the piston has a flat surface portion. A squish area is formed between the flat surface portions of the cylinder head and of the piston. A groove is formed on the inner wall of the cylinder head or on the top surface of the piston so as to extend towards the circumferential direction of the piston. The groove communicates the squish area with the recess. The bottom surface of the groove is smoothly connected to the bottom wall of the recess so as to create a turbulence and a strong swirl motion of the combustible mixture in the recess due to the squish flow pushed out from the squish area when the piston reaches the top dead center.