Research On Direct Stop And Start Process Of Direct Start-stop System

In recent years, our vehicle industries developed rapidly and the number of cars will increase rapidly at present day. The car improves our quality of life and the energy and environmental pollution problem is becoming increasingly conspicuous. Our country's oil supply relies mainly on import and has been anxious. The emission pollution problem has already exceeded industrial pollution. Emissions of NOX, CO and HC are serious threat to the environment. Controlling the emissions from cars have become a national urgent task.City traffic is more complex. The engine will often in the state of idleing. Waiting for the red or traffic jams, idleing time is relatively long. It can make a waste of fuel and serious pollution. Direct Start-stop system can help driver reduce idleing times and save fuel.Gasoline Direct Injection Engine have a good start features , providing a good foundation for developing of Direct Start-stop system. Gasoline Direct Injection Engine is very popular with most of them with this function of Direct Start-stop. Achieving the function with two technical methods: Using assistant motor on Direct Start-stop system and Direct Start-stop with transient back. The two methods were studied respectively in this thesis. Research has focused on the two methods for the process of starting and stopping. Analysis of the process with Cylinder pressure can get important data for optimizeing the process of starting and stopping.This research can be showed in the following:1. Reading the relevant data and paper home and abroad. Analysis that the major method of Direct Start-stop have been shown around. Baseing on the experiment platform, research schemes should be established for the two formulating process of "start" and "stop" relevantively.2. According to the performance data and thestructure data, the whole parameters model with GT-POWER was established. Checking every parameters and keeping them accurately and fairly. Doing measurement of the experiment room's conditions and assigning boundary conditions to the model. There are measurements and collections on the cylinder 's pressure curve with AVL equipment of burning analysis in different speeds. Compareing the experimental results and simulations, checking and regulating the whole parameters model about correctness and calculation.3. Reference to the cylinder 's pressure curve and the width of injection, in the different width and angle of injection ,there is an examin on the situation change of the whole parameters model, it is proposed as an optimize scheme .4. Giving the changing of cylinder pressure in the Idle—stop process and analysing its behavioral characteristics and dynamic changing. In the process of stopping engine , the gas pressure of cylinder has influence on it in the larger. There is an important relationship between the location of pistons and the gas pressure of cylinder.5. Useing the Direct Start-stop system to stop the machine. The location of pistons with the rules have the influence on the gas pressure of cylinder and giving it influencing on the pressure in the compression of the cylinder with an analysis of the experimental results.