Improvement of Combustion by Asymmetric Piston Speed

摘要

Lean-burn and EGR combustion have been developed to improve the efficiency of spark ignition engines, but in-cylinder turbulence must be intensified to achieve a wide range of air-fuel ratio operation. Increasing piston speed generally enhances combustion speed, but the effectiveness of piston speed cannot be optimized because it is zero at the TDC position, where combustion is most affected. On the other hand, a multi-link connecting rod enables an asymmetric piston speed in relation to the crank angle and achieves a remarkable improvement in lean-burn combustion.