Optimization Of 1.6L PFI Gasoline Engine Lubrication System And Its Influence On Energy-saving

As one of the important systems of the engine,the lubrication system not only provides the lubricating,cooling,and cleaning for the engine,but also plays an important role in reducing the friction loss of rotating parts and the driving loss of the accessory system,and increasing the power performance and fuel economy by optimizing the lubrication system.As the national fuel consumption regulation becomes strict increasingly,more and more passenger vehicle enterprises are hard to meet this requirement now.In order to solve this problem,saving energy for traditional engine becomes very important except for developing new energy vehicle.It can be seen by practical application that the friction loss of the engine takes 12% of the total energy loss,while the design of lubrication system affects the friction loss directly.How to develop high efficiency and low oil consumption engine by optimizing the performance of lubrication system becomes very important and it is the main focus of this thesis.The research is based on the 1.6L PFI gasoline engine lubrication system of Dongfeng Peugeot Citroen Automobile Company LTD.It combines the External Characteristic Method(ECM)and the Network Design Method(NDM)to design and optimize the lubrication system of the engine.In this case,it can improve the systematicness of the ECM in design and optimization.And it also can avoid the power loss,which is caused by the shortage of the NDM---not able to determine the displacement of the oil pump accurately.Firstly,how to evaluate the distribution of engine oil pressure by the NDM for the original lubrication system is introduced,the test data and the calculation result are campared to verify the reliability of the calculation model;Then,a VVT system is added and the oil channels are designed and improved,the distribution of the oil pressure under the requirement of VVT system is optimized;After that,from the perspective of optimizing the internal flow resistance of the lubrication system,the structures and the performances of the key oil transfer units are analyzed and improved,it solved the problem of excessive pressure drop of engine oil filter and greatly improved the performance of the engine oil about lubrication?compatibility and coking resistance;Lastly,based on the advantage of ECM and NEM,the vane-type variable displacement oil pump is designed and its performances are optimized,it solved the waste problem of high speed oil supply and increased the fuel economy.Fundamentally,the optimization of lubrication system achieves the goal of reducing almost 3% fuel consumption of 1.6L PFI gasoline engine.The oil distribution according to the need of the lubrication system under the premise of low cost is realized as much as possible.It devotes an important contribution for Dongfeng Peugeot Citroen Automobile Company LTD to meet the fourth stage fuel consumption regulations and lights up a way for designing the lubrication system.