Advanced science.  Applied technology.


Compression Piston Ring Groove for an Internal Combustion Engine


An internal combustion engine including a head (29), a cylinder block (20) containing a cylindrical bore (22) and a piston (27). The piston (27) is located within the cylinder bore (22) of the cylinder block (20) for reciprocating motion in the longitudinal direction of the cylinder bore (22). The piston (27) includes at least one annular groove (32) around its circumference in which is fitted a compression piston ring (40). The piston ring (40) forms a gas seal between the piston (27) and wall of the cylinder bore (22). The lateral surface (34) of the piston ring groove nearest the combustion chamber (24) which is formed by the piston (27) and cylinder bore (22), has formed in it a plurality of radially directed channels (38), each channel forming a gap (46) for introducing gas pressure from the combustion chamber (24) through the clearance space (42) between the piston (27) and cylinder bore ( 22) and into the piston ring groove (32). The combustion gas pressure thus introduced produces a force against the piston ring (40) which keeps it sealed against the surface of the piston ring groove (35) opposite the combustion chamber (24).

Patent Number: 
Date Of Issue: 

Susumu Ariga