Calculation And Analysis Of Deformation Of Cylinder Liner Of 12V265 Diesel Engine

The phenomenon of cylinder liner deformation is common in diesel engine working.The existence of this phenomenon seriously affects the performance of diesel engines.With the development of the society,the goal of "low pollution,low fuel consumption,high efficiency and high reliability" was put forward for the development of diesel engines.During the working process of the diesel engine,the deformation of the cylinder liner will directly affect the cooperation between the piston ring and the inner wall of the cylinder liner and the airtightness of the combustion chamber,which will lead to gas leakage,oil surge and wear,ultimately affect the overall performance,economy and safety of the diesel engine.However,the structure of the diesel engine is complex and diverse,and the problems of static assembly or dynamic extrusion,stretching and heat conduction between the various parts are quite complicated,which increases the difficulty in studying the deformation of the cylinder liner.In order to achieve the development goal proposed by the new era for diesel engines,how to reduce the cylinder deformation problem and obtain the regular conclusions that affect the deformation of the cylinder liner will be very necessary and also be of great research significance.Research on a 12V265 diesel engine being produced and used by a company,with progressive CAE technology,at the beginning of this dissertation,according to the drawings of 12V265 diesel engine,the ideal three-dimensional model of the body,cylinder liner,cylinder head,cylinder gasket and pre-tightening bolt is established,and the contact setting between the parts is completed to simulate the actual contact state of the diesel engine assembly.At the same time,the load boundary conditions of the cylinder liner,such as bolt preload,cylinder gas pressure,thermal load and piston lateral force,are determined and calculated.Secondly,the modal analysis of the diesel engine assembly shows that the diesel engine does not resonate under normal working conditions,and the top of the cylinder liner is predicted to be a dangerous area.The analysis of the temperature field in cylinder liner shows that the temperature distribution of the cylinder liner is uneven,and the cooling water temperature has a great influence on the cooling performance of the cylinder liner.The deformation analysis of the cylinder liner under non-working conditions shows that the deformation of the cylinder pre-tightening force is mainly concentrated on the top of the cylinder liner and the cylinder head contact area.The thermal-structural coupling method is used to analyze the deformation of the cylinder liner.The comparison of the four different loading programs shows that the factor that has a great influence on the axial deformation of the cylinder liner is the pre-tightening force of the bolt,which has a greater influence on the radial deformation of the cylinder liner.The big factor is the thermal load,and the overall deformation of the cylinder liner is mainly reflected by the radial deformation.Finally,the circumferential expansion and Fourier transform analysis of the worst-performing explosion cylinders are carried out,and the cylinder deformation is mainly the second-order and fourth-order deformation of Fourier,and the deformation shape is mainly elliptical and four-petal.