Automatic compression ratio regulating system for octane number measuring machine

The utility model relates to an automatic compression ratio regulating system for an octane number measuring machine. The utility model is characterized in that the system is composed of a high precision displacement transducer, a heat insulation transducer fixing seat, a pair of gear wheels, a regulating motor, a motor supporting rack, a crankcase, a cylinder cover, a compression ratio regulating device, four groups of springs, a spring fixing seat and a cylinder fixing clamp, wherein the high precision displacement transducer is arranged on the upper ends of the compression ratio regulating device and the cylinder fixing clamp through the heat insulation transducer fixing seat, and the regulating motor is fixed on the crankcase through the motor supporting rack and is connected with the compression ratio regulating device through the pair of gear wheels. The cylinder cover is arranged on the upper end of the compression ratio regulating device which is arranged on the crankcase, the four groups of springs are arranged outside the compression ratio regulating device through the spring fixing seat, and the cylinder fixing clamp fixes the compression ratio regulating device. The utility model has the advantages of reliability and high precision automatic regulation of the compression ratio of the octane number measuring machine.