曲面零件的材料去除量建模与试验研究

Modeling and Experimental Research on Material Removal of Surface Parts

航空发动机叶片多为自由曲面类零件,抛磨加工材料去除量的均匀一致性直接决定着零件的产品性能。影响材料去除量的工艺因素较多,且这些因素直接决定着抛磨加工中磨具和工件的接触廓形和材料去除量,精确的控制抛磨接触过程中的材料去除量是实现均匀加工和获得表面完整性的关键。这里首先采用Preston接触理论和MATLAB仿真对百叶轮抛磨自由曲面构件接触区域的接触压强、磨具主轴转速等工艺参数进行分析,建立了材料去除量模型;接着采用单因素试验研究工艺参数和材料去除量规律,求取了Preston系数,对理论建模和试验结果进行对比分析。结果表明,百叶轮抛磨自由曲面的材料去除量和法向接触力的开方、磨具主轴转速成正比,和工件进给速度成反比,该模型具有较高可靠性,材料去除量的计算值和实际测量值误差不超过10%。根据工件不同的曲率半径合理的控制法向接触力、百叶轮主轴转速和工件进给速度能够获得均匀一致的材料去除量。

Aero-engine blades are mostly free-form parts,and the uniformity of material removal by polishing directly determines the product performance of the parts.There are many process factors that affect the amount of material removal,and these factors directly determine the contact profile and material removal amount of the abrasive tool and the work piece in the polishing process.The precise control of the material removal amount during the polishing contact process is to achieve uniform processing and the key to surface integrity.The Preston contact theory and MATLAB simulation are used to analyze the contact pressure of the free-form surface component contact area of the louwer wheel and the grinding tool spindle speed and other process parameters,and the material removal model is established;then the singlefactor experiment is used to study the process parameters and materials removal rule,the Preston coeficient is calculated,and the theoretical modeling and experimental results are compared and analyzed.The results show that the material removal amount of the louwer wheel polishing free-form surface is proportional to the square root ofthe normal contact force,the spindle speed of the abrasive tool,and inversely proportional to the robot feed speed.The model has high reliability and the calculation of the material removal amount the error between the calculated value and the actual measured value does not exceed 10%.According to the diferent radius of curvature of the work piece,the normal contact force,the speed of the louver spindle and the feed speed of the robot can be controlled reasonably to obtain a uniform material removal.