Key Technologies Of CA4DC EURO Ⅲ Diesel Engine Development

In recent years, the legislations for engine emission become stricter and stricter for environment protection. On Jan 1, 2007, the third phase emission legislation and on Jan 1, 2010 the fourth phase legislation will be applied in China. All of the engine manufactures are carrying out performance and emission research and design works to meet the third and the fourth phase emission legislations. In order to meet the market demand, FAW R&D center along with Dalian Diesel Engine Factory have developed CA4DC series electronic controlled CR diesel engines. The main works of CA4DC diesel engine development are described as follows, which is the main content of this dissertation too.Electronic controlled fuel supply system choosing.The 2nd generation common rail system named CRS2.0 was chosen as fuel supply system for CA4DC series diesel engine. The maximal injection pressure of CRS2.0 is 145Mpa. The ECU of CRS2.0 is EDC16C 32-bit single-chip processor. Because of the plenty control modules of ECU, the CRS2.0 can realize muti-injection such as pilot injection, main injection and post injection. The flexible injection model coupled with combustion system optimization make the CA4DC diesel meet the 3rd phase emission legislation and has the potential to meet stricter emission legislation.Combustion system optimization.In order to fully utilize the functions of fuel supply system, a novel combustion system has been developed. The combustion chamber was modified from narrow-deep to wide-shallow. The swirl ratio was decreased and the air-flow factor was increased. By finite element analysis and mechanism development the structures of cylinder block and cylinder head were improved. The hone technics and piston ring structure were ameliorated, which make the lubricating oil consumption to fuel consumption ratio decreased to 0.1 percent. The flow state of cooling fluid was improved by CFD simulation and validated by mechanism development.Engine performance and emission behavior calibration.The calibration process is mainly based on the choosing the best-match of nozzle, combustion chamber shape and intake duct structure. In each combination of the three key parameters the advance angle of fuel supply, rail pressure and nozzle extrude altitude were adjusted many times to reach the best performance and lowest pollutant emission.