Development And Study Of 4-Cylinder 4-Valve Diesel Engine Reached Euro Ⅱ Emission Standard

High speed 4V DI vehicle Diesel engine is a developing direction later on. China has performed great amount of exploration and experimental research for such technology, but it's still in initial phase as actual application. The present paper takes specific 4V Diesel engine version as the object of development and manufacture, more completely studies and expounds the structural characteristic and design requirement of 4V TCI Euro 2 Diesel engine, finally finished the trial manufacture, assembly and experimental research of prototype engine.First of all, the present paper introduces the design characteristic of the head of 4V Diesel engine, the main point of which is analysis and study of intake/exhaust port. Helical port is mainly swirl air movement produced in the port, therefore achieved swirl has no relationship with the valve position of relative cylinder center, valve lift is almost no influence to the swirl ratio. Helical port also produces swirl by airflow interaction of valve gap and cylinder wall, so swirl number depends on helical line direction of relevant cylinder center. Tangential airflow is produced through airflow nozzle against from the valve gap to the outside of cylinder wall, therefore produced swirl depends on the angle between cylinder wall and airflow nozzle, depends on port location and direction and shape of port runner. In the 4V head, airflow interaction of helical port and tangential port, swirl characteristic is smooth in the whole range of valve lift. Helical line (port) is in upstream of tangential port, minimizes the deterioration came from outflow of helical line, and obtains the best support of tangential port airflow.The design of cylinder block is mainly centered on how to improve its strength and rigidity, 4 bolts pattern is used in each cylinder, which is basically in the same axis with the main bearing bolts. Outer wall of water jacket and the skirt is arc structure, arranges some ribs properly, closes the opening of tappet chamber of current product so that good strength and rigidity can be ensured. The small end of con'rod is cuneiform, which not only increases bearing ability, but also the mass of it is the lightest. The crankshaft is treated by good nitriding process, which can meet the strength requirement for Euro 2 emission level (max. cylinder fire pressure 130 bar). The injection pump is BOSCH P7100, the supply pressure can reach 1050 bar, etc.N times harmonic camshaft and mathematics model of kinetic calculation of valve train system are created and relevant calculation program is compiled with MATLAB language of Mathworks company. The result of the calculation shows the nominal valve is bigger at N times harmonic camshaft, which has better charging efficiency. Max. speed of valve and Max. acceleration are small, curves are all smoother, working is stable, vibration, mechanical noise and contacting stress can be reduced greatly, and the reliability and lifetime of the parts are increased.Various performances of the prototype are analyzed and compared directly use measured data of 13 mode emission, the result shows that various performance target of 4V Diesel engine has exclusive advantage in the future. At the same time, pick up a TCI 2V Diesel engine with the same specification and emission meets Euro 2, same set up, test under the same performance target, the result shows that although the intake pressure (equal to intake quantity) of 2V Diesel engine is higher than 4V Diesel engine, regardless of smoke, fuel consumption emission level, 2V Diesel engine is no better than 4V Diesel engine.