Variable Compression Ratio (VCR) Piston - Design Study 2019-01-0243

Variable compression ratio (VCR) technology has long been recognized as a method for improving the automobile engine performance, efficiency, fuel economy with reduced emission. This paper presents a design of hydraulically actuated piston based on the VCR piston proposed by the British Internal Combustion Engine Research Institute (BICERI). In this design, the compression height of the piston automatically changes in response to different engine loads by controlling the lubrication oil flow in the piston with valves. Moreover, some numerical force analysis and oil hydraulic analysis have been implemented to study on the characteristics of oil flow between two chambers in the piston and the response behaviors of piston height and compression ratio at different engine loads.