Compression ratio controlling method for e.g. four-stroke petrol engine of motor vehicle, involves carrying out controlled introduction of compressible fluid acting on face of piston of engine and non-turned toward cylinder head of engine

摘要

The method involves carrying out controlled introduction of a compressible fluid e.g. lubricating oil, acting on a face of a piston (3) of an internal combustion engine (1) and non-turned toward a cylinder head (7) of the engine when a piston (4) is at a bottom dead center at end of an admission phase. The compressible fluid is discharged when the piston (4) is at a top dead center at the end of a release phase. Volume of the fluid is measured and regulated relative to a set-point value of the fluid quantity.