主权项 |
1. A piston type internal combustion engine comprising a cylinder, a piston slidably mounted in the cylinder, a connecting rod through which the piston is coupled to the crankshaft, and intake and exhaust valves,
wherein the cylinder has an interior space which is divided into a lower driving portion in which the piston is mechanically driven, and an upper power portion in which combustion gas is sucked, compressed, burned and expanded, and exhausted, wherein the engine further comprises a cylindrical portion having a lid portion and mounted on a top portion of the piston so as to extend into the power portion with the lid portion facing a top portion of the cylinder, and wherein a gap is defined between the cylindrical portion and an inner peripheral surface of the power portion of the cylinder. |