DYNAMIC VARIABLE COMPRESSION RATIO I.C. ENGINE

摘要

A variable compression ratio piston I.C. engine includes a piston with an inner chamber separated from the combustion working chamber by an orifice. The orifice is geometrically shaped to restrict transfer of gas from the working to the air chamber by causing a choked flow condition to exist across the orifice when the piston speed exceeds that speed at which the critical pressure ratio occurs across the orifice. This prevents pressure equalization between the working and air chambers at the end of the compression of the charge supplied to the working chamber above a selected engine speed to cause an effective increase in engine compression ratio above such speed. A specific piston structure for carrying out the invention is disclosed.