Deviation Calculation And Control Of Balance Weight's Processing Quality In Three-Cylinder Engine Balance System

The balance weight of three-cylinder engine balancing system is the key part to determine the balance performance of the engine,whose processing quality affects the balance quality of the system directly,and then affects the running stability,vibration and noise of the engine.Therefore,the processing quality of the balance weight must be guaranteed to meet the design requirements.Aiming at the deviation calculation and control for the processing quality of the balance weight,the main research work of this paper includes:(1)In order to research the effect of processing error on the processing quality of the balance weight,the tolerance model of the plane and cylinder features of the balance weight is derived and established based on the small displacement torsor.The error components of the feature variations are constrained in the tolerance zone.On this basis,the calculation model of the processing quality deviation of each feature and the calculation model of the processing quality deviation of the whole part are established,which provide the foundation for the analysis and control of the balance weight's processing quality,and design physical experiments to verify the accuracy of the calculation model.(2)According to the analysis of processing quality's deviation range involves a large amount of calculation and high accuracy,the random sequence in traditional Monte Carlo simulation method is replaced by the low-discrepancy sequence constructed by the method of number theory.According to the distribution characteristics of the processing error of the balance weight,a Monte Carlo simulation method with low-discrepancy sequence is put forward,and the quality deviation range of balance weight is calculated based on examples.The calculation example shows that the Monte Carlo method with low-discrepancy sequence keeps the similar accuracy and has a faster convergence rate compared with the traditional Monte Carlo method.(3)In order to determine the key factors affecting the machining quality deviation of counterweight block,orthogonal experimental design method is adopted to analyze the influence of balance weight size,shape,position error and material density on the processing quality.The significant impact of various processing error on machining quality is obtained by analysis of variance.A fuzzy mass loss model of the dimensional tolerance and shape tolerance of the balance weight is derived and established.Taking the total cost of the balance weight as the objective function and the processing quality deviation and processing precision as constraint conditions,the tolerance optimization model of balance weight is established.The genetic algorithm is used to solve the optimization model and carry out an example analysis to verify the reliability of the tolerance optimization model of the balance weight.(4)The sensitivity analysis of the quality deviation of the balance weight is applied to the design and manufacturing stage of the balance weight.The reasons and adjustment methods of the key processing parameters of the parts in the actual manufacturing are analyzed.The implementation process of quality control for balance weight is discussed,and the quality control strategy of balance weight is put forward,so that the quality control of balance weight can be realized in design and manufacture stage.The research work in this paper can provide a technical basis for the quality control of the three-cylinder engine balancing system balance weight,which is conducive to improving the processing quality of the balance weight and ensuring the performance of the three-cylinder engine balancing system.