Study And Development Of YC6M Heavy Duty Diesel Engine

The four valves diesel engine technology is one important measure to increase the performance and the exhaust emission behavior of diesel engine. The development of high-speed four valves diesel engine represents the way of heavy vehicles development .The thesis introduced the whole process of heavy diesel engine YC6M designing from two valves turbocharged engine to four valves turbocharged and intercooled engine, BOOST calculation and matching tests . The exploitation work of YC6M engine was advanced under the backgroung that a lot of 300PS diesel engines were needed during the development of nation economy and road build. From the need of self development, for the sake of glomming the potential market and obtaining great profit, YuChai advanced the exploitation of YC6M diesel engine with 120mm cylinder diameter, 145mm stroke, 9.839L exhaust capacity. its power output ranged from 220PS to 380PS and will be used in 50 series loading machine, 60 series loading machine, high-power generator set, ship, heavy duty truck and cement mill machine. This investigation firstly narrated the designing technology, configuration character, expect parameter of two valves YC6M heavy diesel engine and whole process of performance exploitation. Then , under the base of two valves diesel engine ,we integrate the configuration character and techniques consistency of two valves YC6M diesel engine, establish the disposal project of valves and gas road, size and position of valves, select the parameter of gas road ,design the cylinder head and rocker machine, match the combustion system and supply oil system again. Last, we exploited successfully the four valves YC6M heavy diesel engine that can reach the Euroâ…¡emission standard. The result of platform tests indicates that the four valves engine have batter performance comparing to the two valves engine. its power greatly increased, economic performance improved, the range of fuel economic area extended, the fuel consume rate reduced. YC6M heavy diesel engine designed finally can be satisfied with the Euroâ…¡emission standard. Now parts of model have been produced in batches, therefore, two valves turbocharged diesel engine has been applied for work machines that made by XuZhou Machine Factory, LiuZhou Machine Factory, ShangDong Machine Factory and JianDe Machine Factory. Two valves turbocharged and intercooled engine has been adopted to ChongQing HongYan Automobile Plant, LiuZhou Automobile Plant, ShanXi Automobile Plan, ShangHai Automobile Group Co., Beijing Automobile plant and the Second Automobile Plant etc, and obtained good profit. The full load characteristic of YC6M four valves diesel engine meet the designing command, now we are going along the third round machine exploitation and it will be put into market in the near future. During the process of the engine performance exploitation .We adopt the performance simulation compute software BOOST to calculate the approximately performance of engine .We compare the test data to that BOOST calculates, the two results are anastomosed, the error is within 5% , considering the difference between the calculation conditions and the test conditions, and the self error of the data, the calculation result should be much corrective, and can truly represent the performance of diesel engine.So we could adopt the simulation calculation of BOOST software to guide the design, that could shorten the exploitation period, reduce the test times, accordingly reduce the exploitation cost. Exploitation of YC6M could accumulate experience to exploit other type engine besides obtain lots of economy benefit. During the process ,we did lots of intersected contrasted tests for different state parts, such as infection of different advance angle on performance, the infection of different injection pressure on exhaust and performance, heat release disciplinarian of different angle, burst pressure etc. These data can be applied for guiding the exploitation and optimization of other engines. Through the investigation and exploitation of YC6M heavy diesel engine, we can make the conclusions as follows. 1. After adopted four valves technology, the circulation section area of valves will be increased greatly, charge efficiency can be improved, that disposes the nozzle in the middle, improves the distribution of fuel and air in the cylinders, and obtains all tight combustion quality. Comparing to the two valves engine, fuel consumption rate and exhaust temperature decreased greatly, exhaust smoke is higher than two valves engine at demarcate point, the other points are lower than the two valves engine, it's evident at low and middle speed. 2. There are loss between two valves in four valves engine, we should reduce the loss reasonable and match the swirl ratio reasonable, meanwhile, that can exerts the advantage of four valves technology and decrease the NOx and PM displacement . 3. The simulation calculation can optimize the parameter, guide the exploitation, decrease the exploitation period and decrease the test time and cost . 4. As turbocharged and intercooled engine as concerned turbocharger match is necessary, that the match is whether reasonable or not refers to the performance changing and the exhaust of NOx and PM emission. 5. The change of engine boost pressure effects the combustion in the cylinders, we can adjust the boost pressure suitably under the permission of dependability . 6. The changing of engine intake temperature effects the engine performance and emission behavior, decrease of intake temperature can improve power output, fuel consumption effectively and decrease the NOx and PM emission. Effective and compact intercooler in turbocharged and intercooled engine should be designed.