YC-6K Diesel Engine Piston Failure Analysis And Structural Optimization

Since 1860, the first internal combustion engine has been created; the history of the piston engine has lasted nearly a half century. The development of the engine is a process that from low-power, low efficiency towards high power, high efficiency. Especially in the past few years, due to the demand of power by heavy trucks and engineering machinery, high speed, high efficiency and high enhanced engine is developed with a variety of new technologies, new materials. Being the heart parts of diesel engine, as the heat load and mechanical load's increasing, the possibility of failure in the piston is also increasing. Therefore, the research and optimization on the heat transfer structure of the piston has become a constraining bottleneck in the power enhancement diesel engine, so it needs to focus on this part.Diesel engine power enhancement is generally characterized by ascending power, the higher the degree of enhancement, the higher the ascending power. YC-6K diesel engine is a power of 31.2kW/L, due to the high enhanced, the original design of the piston has a cracking failure. Therefore, we need focus on the analyzation of the piston of YC-6K. In general, the piston cracking failure was mainly due to two reasons, the first one is the high temperature of the piston, the materials of the piston reduces the strength; the second one is piston stress structure is irrational, there was a weak point. In order to conduct a study of temperature piston, it needs to size the combustion chamber of the piston and needs to calculate the cooling effects of the heat transfer of the cooling chamber. Need help with the finite element analysis software ANSYS and flow calculation software FLUENT. In order to study the stress of the piston, the piston's stress (including thermal stress condition and mechanical stress conditions) were need to be analyzed with the software ANSYS and ANSYS-WORKBENCH.In this paper, combined with the results of the research at home and abroad over the pistons, doing some research on the structural of the piston used in YC-6K, and it get a lot of results. The first one is proposing a method to get the heat boundary of the piston rapidly with using the Hardness plug temperature measurement, RBF neural network and ANSYS. The second one is doing some research on the cooling effect of the cooling oil chamber and the effect of the position of the cooling chamber of YC-6K diesel, with using the FLUENT. The third one is using the ANSYS and ANSYS-WORKBENCH to find out the longest transfer route of the head of piston, doing some research on the temperature effect of the radius of the combustion chamber throat. The fourth one is doing some research on engine piston's thermal stress and coupled thermal-mechanical stress problems, and identifying the main reason for destroying the piston is the piston's high temperature with using ANSYS and ANSYS-WORKBENCH. Through the above research results, the optimization methods proposed is to reduce piston temperature, optimal way is to increase the piston chamber radius throat, increase the cooling oil chamber axial position, and the simulation program mentioned above to find out the best optimal program.