Compression ratio control mechanism for internal combustion engines

摘要

An intake manifold arrangement for internal combustion engines whereby the combustion chamber can be supercharged without the use of mechanical gears and/or pumps. A pressure chamber is mounted upon the combustion chamber and communicates with the combustion chamber and an air and fuel mixture supply. A check valve for selectively allowing the mixture to enter the pressure chamber is provided between the air and fuel supply and the pressure chamber. An intake valve for providing selective communication between the pressure chamber and the combustion chamber is provided and controlled by the compression ratio control mechanism. The compression ratio control mechanism includes an axially slidable cam having a lifting surface of greater duration axially at one end of the cam than the other end of the cam. The cam is selectively axially shifted by an accelerator pedal which controls a hydraulic piston coupled to the cam. The intake valve is opened during the intake stroke and the mixture is drawn into the combustion chamber. The pressure chamber is pressurized during the compression stroke while the intake valve is open and the compression ratio in the combustion chamber is selectively controlled by closing the intake valve at a point during the compression stroke by the selectively slidable cam. An exhaust boost or scavenging arrangement is provided whereby pressurized air is selectively forced into the combustion chamber.