What is the working principle of the Atkinson cycle?

[RyanFitz]

The Atkinson cycle is based on the Otto cycle internal combustion engine. By using a set of complex linkage mechanisms, Atkinson made the compression stroke of the engine smaller than the expansion stroke. This ingenious design not only improves the engine's intake efficiency but also ensures that the expansion ratio is higher than the compression ratio, effectively enhancing the engine's efficiency. This working principle is known as the Atkinson cycle. The Atkinson cycle engine primarily features the following three technical characteristics: By increasing the compression ratio to 12 and relatively reducing the combustion chamber volume, the engine achieves higher thermal efficiency. Through a completely redesigned valve timing, the engine's expansion ratio is increased without a significant rise in the compression ratio, thereby avoiding the occurrence of knocking. By optimizing the matching of the electronic fuel injection system and adjusting the fuel injection quantity and ignition timing, the engine's thermal efficiency is further improved, and the fuel consumption rate is enhanced.