Failure Analysis And Research Of Ignition System For Turbocharged Gasoline Engine

Ignition system is an important part of gasoline engine,it is the key to ensure the ignition of the engine.The failure of the ignition system has a great impact on the performance of vehicle’s power,fuel economy,emissions and NVH,and further seriously affects driving and safety of the vehicle.Therefore,failure research of the ignition system is significant for the automotive industry.The paper starts with failure characteristics of a self-owned brand turbocharged gasoline engine ignition system,focusing on the mechanisms of electronic ignition system,and analyses the structure,function of major components and their corresponding features.For the purpose of failure analysis of ignition system induced by ceramics cracking of the spark plug,tests have been conducted on engine performance for cases with different ignition positions of the spark plug,ruling out the failure induced by ignition position of the spark plug.Then,the temperature variation of the spark plug under different conditions are tested,revealing that the interactional pattern between the spark plug temperature and engine performance,also revealing that spark plug temperature does not lead to the failure of ignition system.Later on,research is extended to the tendency of engine prior ignition,concluding that the ignition system failure is not owing to engine body overheat.Finally,tests are carried out on the spark plug ignition voltage and ignition coil supplied voltage,as a whole system,investigating the initiation,transmission and ignition process of ignition pulse high voltage and the corresponding mechanisms.The main reason for ignition system failure is confirmed,with the increasing ignition voltage of turbocharged gasoline engine,the mismatch of major components’ function inside of system causes the supplied voltage of ignition coil higher than the resistant voltage of spark plug,thus leading to the breakdown of the ceramic body by high voltage.This paper also proposes three strategies to prevent the failure of ignition system,namely,improving the ability of withstanding voltage of the spark plug ceramic body,adjusting the supplied voltage of ignition coil,reducing the spark ignition voltage.Effectiveness of these measures is verified through engine and vehicle durability tests.This paper not only solves the problem of ignition system failure,but also tidies up the detection and analysis method of system failure,which provides theoretical and engineering guidance for the research and development of turbocharged gasoline engine ignition system.Finally,with the increasing stringency of the vehicle fuel consumption and emission regulations,higher requirements for the ignition system will be put forward by future high efficiency,low emission engine,so,research on new technology in ignition system has been discussed.