STUDY OF THE INFLUENCE OF MISFIRES ON THE UNEVEN ROTATION OF THE CRANKSHAFT OF A GASOLINE ENGINE

Abstract

Purpose. Investigate the effect of misfires on the unevenness of the torque on the crankshaft of gasoline internal combustion engine with spark ignition.
 Research methods. The results of the thermodynamic calculation of the operating cycle, the dynamic calculation of the engine parameters at the nominal operating mode of an well engine and an engine with misfiring in one cylinder are presented. The computer program Engine Calculation and Microsoft Office program package were used to perform the research. The object of the study is the MeMZ-245 four-stroke, four-cylinder gasoline engine. The subject of the study is the torque unevenness coefficient of the internal combustion engine μ.
 Results. The topical issue of investigating the impact of misfires on the indicators of unevenness of rotation of the crankshaft of a spark-ignition internal combustion engine has been solved. The torque unevenness coefficient μ = 6.164 for the MeMZ-245 4-stroke 4-cylinder engine when operating at the nominal mode was calculated. It was established that as a result of a malfunction (disabling one cylinder), the average effective torque of the engine decreases by 29.4%. The value of the torque unevenness coefficient of the faulty engine was calculated as μ = 12.165, which is twice the value for the well-worked engine. It was established that level of torque unevenness of MeMZ-245 4-cylinder in-line engine with misfiring approaches to single-cylinder engines.
 Scientific novelty. For the first time, it was theoretically proven that due to the lack of ignition in one of the cylinders of a 4-stroke 4-cylinder engine, the average effective torque of the engine decreases by 29.4% when operating at the nominal mode. The value of the torque unevenness coefficient μ of an engine with misfiring is twice the value for a well-worked engine, which is close to similar values of single-cylinder engines.
 Practical value. The method of calculating the torque unevenness coefficient of an internal combustion engine can be used in the design of new and modernization of existing internal combustion engines.