Improvement And Verification Of Cylinder Lubrication Model Considering Structural Dynamic Deformation

Piston ring-cylinder liner as one of the key friction in the internal combustion engine,the friction and lubrication performance can directly affect the performance of the internal combustion engine.Therefore,the research on the lubrication of piston ring-cylinder has been paid more and more attention.It is important to study the friction and lubrication of piston ring-cylinder liner and improve the lubrication state of friction ring.research direction.In most of the piston ring-cylinder lubrication models established in the past,most studies have assumed the surface of the cylinder liner as the ideal cylindrical surface,without considering the effect of the dynamic deformation of the cylinder liner on the lubricating oil film forming process and lubrication performance.At the same time,the previous study did not consider the effect of roughness hole on friction lubrication.Therefore,it is necessary to establish a lubrication model considering cylinder liner deformation,friction surface roughness parameters and hole effect.In this paper,the finite element model of the cylinder liner is established,and the dynamic response of the cylinder liner under the two main excitation sources is predicted based on the established model.The dynamic response between the local cylinder and the excitation source is analyzed.Corresponding relationship,obtained two kinds of excitation source caused by the deformation of the cylinder.It can be seen from the simulation analysis that the amplitude of the deformation of the cylinder liner is the same as that of the piston ring-cylinder liner friction surface surface roughness.Due to the different physical and chemical properties of the alternative fuel and 0 # diesel fuel,the difference of the vibration response of the cylinder liner is predicted based on the finite element model.The dynamic response of the cylinder with different fuels was analyzed by continuous wavelet transform.It was confirmed that the vibration response of the different fuel to the cylinder was significantly different,and the piston thrust in the vicinity of the combustion top dead center was reduced with the increase of the engine speed Then,in order to further study the potential effect of structural deformation on the tribological behavior of the cylinder liner,a lubricating model considering the dynamic deformation of the cylinder was developed based on the average Reynolds equation and the improved flow factor and the hole effect were used to obtain a closer Lubricating oil film formation,distribution and tribological behavior.Through the establishment of the lubrication model,the piston ring and cylinder liner can be obtained between the film thickness,friction and oil film pressure distribution,predict the piston ring and cylinder between the lubrication state.Finally,a series of bench tests were carried out on three-cylinder diesel engine.The friction and lubrication characteristics of piston rings and cylinder linings under different working conditions were analyzed.By comparing the root mean square values of different fuel vibrations to corresponding cylinder liner dynamic deformation.The results show that the dynamic deformation of the cylinder caused by different fuels is similar to the numerical prediction results.The acoustic emission signal is analyzed by wavelet envelope method,and the rationality of the model is verified.Through the demolition of the cylinder inspection to further confirm the engine cylinder liner at the top dead point there is a serious wear and tear,the improved lubrication model for the future piston ring-cylinder liner friction lubrication research and design improvements to provide theoretical guidance.