Method for the determination of the residual gas in the combustion space of a cylinder of a four stroke internal combustion engine

摘要

The inlet valve spread (21) and outlet valve spread (22) as well as the inlet and outlet valve travel (23 and 24) are found during a single cycle, taking outlet valve spread (22) and outlet valve lift (24) from a first characteristics diagram (25) to find a first residual gas content (26) equal to the gas volume between piston top dead center at charge change and the outlet valve closure moment as the volume of gas drawn back into the cylinder combustion space through the outlet valve. Inlet and outlet valve spreads (21) and 22) and the inlet and outlet valve lifts (23 and 24) using characteristic diagram (27) show the valve overlap surface as well as content per unit area and shift towards top dead center at charge change. From this is found the proportion of residual gas flowing over the cylinder from the inlet valve in the time between inlet valve opening and outlet valve closure. This enables the residual gas content in the cylinder to be determined by summating first (26) and second (28) residual gas contents. Ignition angle (33) is found from panel (32) from the residual gas content (31).