| 摘要 |
In a spark-ignition engine the compression ratio is varied by movement of a spring-loaded piston (1) in a secondary chamber (2) contiguous with the clearance volume of the main combustion chamber (3). The position of the spring-loaded piston (1) is determined by tension of the spring (17) acting against absolute pressure in the engine cylinder during the induction phase. During other phases of the engine cycle the piston (1) is prevented from movement by hydraulic lock of fluid in the space (11) behind the piston (1). Thermal efficiency is improved by increase in peak combustion pressures under part-load conditions. In the disclosed arrangement a spark plug (12) is housed within the piston (1). |
