The Research On ISG And EFI Of Small-scale Gasoline Engine

With the deepening of industrialization, the situation of environmental pollutionand energy shortages are becoming worse. However, the technology of energyconservation and emissions reduction of small internal combustion engines are notpaid enough attention.ISG (integrated starter generator) technology is a mature technology in terms ofautomotive hybrid applications, however, it has fewer practical application in a smallengine. Applying ISG technology can improve the engine cold start performance,improve fuel economy and reduce noise and torsional vibration, meanwhile iteliminate the flywheel, generator, starter motor, and related transmission parts, whichis advantageous for simplification and modularization of the system. Free armatureinjection technology is a pump nozzle integration EFI(electronic fuel injection)technology. It simplifies the fuel injection system with a certain precision, whichmakes it more suitable for application in small engine EFI modification. With thecombination modify of EFI and ISG technology on small engine, it can effectivelyimprove the fuel economy, emissions and dynamic performance. This thesis is mainlydiscuss the EFI and ISG technology modification scheme on a small gasoline engine,and make research on the modified system.This thesis analyzes the domestic and foreign research on the application of someISG system, then demonstrates the principle and advantages of free armature injectiontechnology on small internal combustion engine.Secondly, this thesis make a discussion on the model selection of motor andcalculation some of parameters according to the motor operating requirement.Thendetermine the internal parameters and materials of motor according to the startingtorque, cost factors, etc.Using Ansoft Maxwell to make a electromagnetic simulation of the motor fordetermine the reasonableness of the motor parameters, and to optimize motorparameters by the simulation result. Finally, according to the market research,purchase the motor meets the requirements. An16-bit micro controller is used to builda motor control platform, a three-phase full-bridge power MOS power transistor isused to build a three-phase full-controlled rectifier. The modification of original carburetor engine prototype include electronicthrottle control program design, the ignition angle standard modification, theinstallation of the oxygen sensor, fuel line modification and so on. Developed aoxygen sensor which is used on small-scale engine to ensure oxygen sensorperformance parameters, which is key to EFI closed-loop control.Meanwhile, in order to better match the modified engine, optimize its overalldynamic performance, fuel economy and emissions, the research use Labview graphiclanguage to establish the Dataview calibration system including the engine ECU MAPmatching and calibration of key parameters. The research also makes a simplificationand optimization on the hybrid strategy. After the ISG device installed onto the EFIsmall engines, the research conducted bench testing under different conditions, usingDataview calibration software to test parameters and control strategy for optimization.Finally, experiment research is conducted on the modified system, including fuelconsumption, emissions, and cold start performance, propose some points of views forthe further improvement.