Study On Closed-Loop Control Electric Fuel Injection System For Motorcycle Engine

In this study we developed a closed-loop electric control system,which used Electric Fuel Injection (EFI) and Three Way Catalyst converter (TWC) technology,on GY6 125ml scooter engine．We selected the controls parameter of the system on LZDC-15 direct current electrical dynamometer system．Then on the base of this work we do some experiments to compare the power,the economy and the emission performance with the original engine．During the research we used the EFI technology,which used on the automobile engine as a reference．But this technology can't be used on the motorcycle directly because of its high cost．So in order to lower down the cost of the system,we do some modification and simplification work on it．After the modification,the system can be fit for the application on the motorcycle very well．In the system we don't use the common method to control the A/F．We adopt a new one,which called the duty-ratio-control method to do so．By using this kind of method we can simplify the hardware and the software and enhance the stability and anti-jamming performance of the system．In the research we also use a new method to estimate the fuel consumption of the engine．It is very hard to measure the fuel consumption of the EFI system directly．But we must get the data to compare with the original engine．After some study we found that through the characteristic of the nozzle we can estimate fuel consumption．By this way the problem has been solved．It has been testified by the experiment that the system can accurately control the A/F of the flammable mixture．Using together with the TWC,the system can lower down the emission of the engine greatly．At the same time the average power and torque are higher and the fuel consumption is lower down than before．Because the system can control the A/F accurately,we use it to get the output characteristic curve of the oxygen sensor．Through applying this system on motorcycle we can enhance the power and economy and lower down the emission performance of the vehicle．On the other hand the cost does not raise more．After some matching work the system can be applied on almost all kinds of motorcycle engines．We trust that the system has a good future．...