Piston and piston ring for an internal combustion engine

摘要

An internal combustion engine includes a cylinder block, a piston and a piston ring. The cylinder block includes at least one cylinder bore which includes a cylinder bore surface. The piston is located within the cylinder bore of the cylinder block so as to be displaceable upwardly and downwardly in the longitudinal direction of the cylinder bore. The piston includes at least one annular groove which has at least one inclined surface such that a bottom of the annular groove is located lower than an outer edge of the annular groove. The piston ring includes an outer peripheral portion and an inner peripheral portion. The inner peripheral portion of the piston ring is located within the annular groove of the piston for sliding engagement with the inclined surface of the annular groove of the piston. An inner edge of the inner peripheral portion of the piston ring is located apart from the bottom of the annular groove of the piston, and the outer peripheral portion of the piston ring is in contact with the cylinder bore surface of the cylinder block.