Internal combustion engine with load-responsive valve control for combustion chamber scavenging

Claim 1

An internal combustion engine comprising a cylinder having a combustion chamber and a piston movable in the cylinder, at least one intake valve communicating with the combustion chamber, at least one exhaust valve communicating with the combustion chamber, wherein the opening phases of the intake valve and the exhaust valve overlap at the bottom dead center position to permit combustion chamber scavenging with fresh gas, and wherein the compression stroke is defined by the closing time of the intake valve or the intake valve last to close, respectively, and the top-dead-center position of the piston and the power stroke is defined by the top-dead-center position of the piston and the opening time of the exhaust valve or the exhaust valve first to open, respectively, and valve control means for increasing the compression stroke with decreasing engine load by advancing the closing time of the intake valve or at least the intake valve last to close, respectively, as a function of load.