Research On Block Assembly's Structural Design Compatibility Of Diesel Engines

Different types of diesel engines have different parts structure.Moreover,the fitting conditions of the diesel engine in the actual assembly are different.The structural coordination of diesel engine refers to the comprehensive influence of a diesel engine on its existing parts structure and actual assembly conditions.The comprehensive performance index of diesel engine under different working conditions.If a key structure of cylinder head is changed,such as airway,bolt hole position,etc.Under static conditions.Diesel engine cylinder liner(wet)under the action of pre-tightening force will have certain deformation,due to the change of the structure,lead to transfer of prestressing force will change too,eventually making cylinder liner deformation trend change Under normal operating conditions of diesel engine,due to structural changes,the cylinder liner deformation is not reasonable,which may cause the piston ring seal to be poor,leading to serious gas transmission,emission,combustion and other performance degradation.Although it is only changing one or some key structures,it is the more components of the diesel engine that affect the performance of the diesel engine.Work in this paper,main contents,including setting a set of cylinder profile measurement scheme,for the convenience of analysis,the diesel engine cylinder liner made up for 1-4,to eliminate the liner itself because of the influence of processing error,installation error of measurement,the cylinder liner deformation is measured in front of the assembly,the assembly after the measured cylinder liner deformation data minus before assembly,after applying bolt pre-tightening force is the deformation of the actual value of the cylinder liner.Hole diameter measuring cylinder diameter and body steps,the cylinder liner and cylinder hole combination matching,get 4 different set fit clearance of cylinder liner,cylinder hole,in order to study the influence of fit clearance of cylinder liner deformation.According to the analysis and arrangement of the test data,the radial deformation and axial deformation of the cylinder liner were studied and analyzed,and the roundness of the cylinder liner in the upper,middle and lower sections was obtained.Establish finite element model of diesel engine to a cylinder as the research object,applying normal extraction of cylinder liner deformation bolt pre-tightening force,compared with test results of calibration,set different fit clearance,get the maximum cylinder liner,minimum deformation effectively,the fitting clearance further analysis to the influence of the cylinder liner deformation.Of the dimensionless group key body structure stiffness,set up the five groups of different fit clearance,calculation on the cylinder liner,middle and lower dimensionless radial stiffness,the response surface method is used to get the distortion and gas explosion pressure of cylinder liner deformation,radial dimensionless central cylinder liner,fitting relationship.The dynamic model was set up to reduce the body group,and the influence of engine speed on the surface vibration of cylinder liner was studied.