Research On On-line Testing System For Vehicle Fuel Injector

As a core component of automobile engine,fuel injector’s working performance directly influences automobile engine’s dynamic performance and exhaust emission.During the automatic production of fuel injector,it is of great significance for production quality management,deficiency management and technology improvement to online and accurately test the working performance of fuel injector.In the dissertation,the structure and working principle of port fuel injector are analyzed and studied,which provides theoretical basis for the testing working of port fuel injector.“SAE J1832-2001 Low Pressure Gasoline Fuel Injector” issued by Society of Automotive Engineers,“GB/T 25363-2010 Electromechanical Solenoid Fuel Injector Assemblies of Gasoline Engines—Testing methods” proposed by China Machinery Industry Federation,and Automobile Industry Standard “QC/T 967-2014 Port Fuel Injector for Gasoline Engine” and other test criteria are taken as the gist for design system,on-line testing system for vehicle fuel injector is constructed,and it may establish standard test environment,conduct reliable test on working performance of port fuel injector,complete the work such as theoretical analysis,mathematical modeling and system development of mechanical part,electrical part and software part of testing system,realize the automatic judgment on port fuel injector of voltage type and current type,test its flow characteristic and jet failure(short circuit and open circuit),and also conduct standard testing on dynamic response characteristics of prot fuel injector of voltage type.In the dissertation,the relevant experimental verification is conducted on pressure control subsystem and fuel injector driver subsystem of testing system.Meanwhile,the testing and analysis are conducted on flow characteristic of port fuel injector of voltage type and current type and dynamic response characteristics of port fuel injector of voltage type.The dynamic flow and static flow curves and important parameters of port fuel injector are summarized,and the influences of different injection pressures and drive voltages on the dynamic response characteristics of port fuel injector of voltage type are analyzed,and moreover,the result analysis is also finished.The testing data show that this testing system possesses good stability and reliability,is able to accurately test the important parameters of working performance of port fuel injector,and meets the judgment standard of port fuel injector.