Study And Application Of A Combustion Measuring Platform For Small High Speed Gasoline Engines

The test and control of combustion process are cores for the process of the motorcycle engine research and development, and is link for the engine each performance evaluation and control, and are foundations to carry out research on emissions, oil consumption and noise control and so on. Therefore, it is necessary to develop measuring platform of combustion work process for the small high speed gasoline engine, which will provide a basic tool for the enterprise next product development.In view of compact characteristic for motorcycle engine structure, one-cylinder wind cooling and high speed, in order to guarantee the combustion process test precision and the reliability, lectotype, installation, adjusting of the combustion analysis system instruments were researched, designed installing hole and the adaptor of the cylinder internal pressure sensor, installing the seat cover of the inlet and the exhaust pressure sensor and the cooling water cycle system, as well as the installing connector of the crank angle sensor and the measure of shock absorption.Based on the combustion testing platform, some basic data were measured, such as the instantaneous cylinder internal pressure, the inlet pressure and the exhaust pressure, and the engine crank angle speed and so on. Through these testing data, some important combustion characteristic parameters such as diagram of work, indicate mean effective pressure, cyclic variation of combustion pressure, the maximum of combustion pressure and crank angle position, the maximum rate of combustion pressure rise and crank angle position, the maximum fluctuation for rate of pressure rise, fluctuation of inlet and exhaust pressure, combustion knock intensity, rate of combustion heat release, the accumulative of combustion heat release and so on, were analyzed to how to influence the engine combustion law in the strong combustion period and the post combustion period.The cylinder internal combustion pressure was filtered on high frequency and the low frequency, the dynamic engine knock intensity calculation method was employed to analyze change and the distribution of the combustion knock at the different rotational speed and the load. At the same time, the engine heat release rule at the different operating mode was studied, fitted the combustion quality parameter m value which matches with the actual result, and inferred the change rule of the combustion quality parameter m value, which provided the effective accurate foundation parameter for the exothermic analysis computation simulation model.As the testing result was proved, this combustion tests platform is a set engine combustion analysis system of dynamic response quickly, accurate highly, excellent reliability, it can widely be applied in the test of engine work process.