The Influence Factors Of Machining Accuracy Of Internal Combustion Engine Piston

With the development of high strength, high performance and high reliability of the internal combustion engine, higher requirements have been put forward for the performance of internal combustion engine. The piston is the core component of the movement and power transmission, and the machining quality and process stability directly affect the performance and life of the internal combustion engine. In order to control the piston processing quality effectively, it is necessary to study the factors affecting piston processing quality and the influence rules based on the stress and strain. The main contents:1. Based on the Johnson-Cook flow stress model, the cutting force under the action of the sharp cutting tool, the ploughing force under the action of the cutting edge radius and the cutting force model on the flank of the cutting tool are calculated using the Merchant formula and the correction formula of shear angle. The influence of flank wear length on cutting force is analyzed.2. A prediction model for the temperature distribution of the workpiece is established by the mirror heat source method. The validity of the model is verified by the finite element method. The changes of cutting temperature, cutting force and residual stress under different environmental temperatures are analyzed. The thermal deformation of the cutting workpieces is calculated by thermoelasticity theory, and the influence of cutting speed and workpiece radius on the thermal deformation of the workpiece is analyzed.3. The clamping force of the cutting process is calculated based on the cutting force, and the maximum deformation of the piston is analyzed under the action of different clamping and clamping force by orthogonal test and the finite element software. The different regression equations for predicting the clamping deformation are established. Based on the residual error and error analysis, the optimal deformation prediction equations are established under the condition of the known geometric parameters of workpieces and cutting parameters.4. The piston solution and aging heat treatment and cryogenic treatment processes are made. The changes of the temperature and stress under the condition of the solution and aging heat treatment and cryogenic treatment processes are simulated. The heat treatment process and the number of cryogenic under the minimum stress are obtained.