Abrasive belt grinding is one of the important means to improve the accuracy and quality of free-form surface.Aiming at the shortcomings in the efficiency and accuracy in the process of belt grinding of free-form surface,based on the characteristics of abrasive belt grinding,a trajectory planning method for abrasive belt grinding free surface was proposed by machining accuracy control.First,the radius of curvature of grinding interference and fabrication tolerance of the grinding wheel width were deduced,thus with the analysis of grinding wheel and machining surface points principal curvature,the processing requirements were optimized by genetie algoviyhm double out to meet to free surface error,and the contact wheel size parameters of no curvature interference processing requirements was obtained.Then,based on the principal curvature direction of the machining points,the adaptive strip-width maximization planning of the machining path was realized,and algorithm for the compliant treatment of the surface distortion in grinding head axial potential oscillating were studied,finally the grinding path which has the space stability and meet the grinding wheel contact point was gotten.Finally the processing of the experiment was verified by the trajectory planning method of a certain type of aero-engine blade the surface with CNC abrasive belt grinding machine.The results showed that the blade profile accuracy by using the method of trajectory planning after grinding can better meet the corresponding tolerance requirements,and the surface quality and accuracy of blade profile were improved,and the validity and practicability of the grinding path planning for free-form surfaces were verified.The method can be expected in control of machining error,solves the problem of contact local interference problems caused by improper selection of parameters of grinding wheel size,and the efficiency and accuracy of abrasive belt grinding can be effectively improved.%砂带磨削是提高自由曲面工件型面精度和表面质量的重要手段之一,针对目前自由曲面砂带磨削加工在效率和精度方面存在不足,基于砂带磨削加工的特性,提出了一种基于加工精度控制的自由曲面砂带磨削加工的轨迹规划方法.首先,对实现无曲率干涉的接触轮半径及满足加工允差的接触轮宽度进行了公式推导,结合轮与曲面上加工点主曲率关系,通过双倍体的遗传算法优选出满足自由曲面要求的加工允差,并获取无曲率干涉加工需求的接触轮尺寸参数.然后,基于加工点的主曲率方向实现加工轨迹的自适应宽行距规划,同时采用柔顺处理算法对其点导动规划过程中当曲面存在扭曲时的磨头潜在的大幅往复摆动运动进行了柔顺处理,获得了行距稳定且满足加工时接触轮在磨削点处始终与自由曲面达到最佳贴合效果的磨削轨迹.最后,应用该方法对某航空发动机叶片型面进行轨迹规划,并在数控砂带磨床上进行了加工验证.结果表明:规划的磨削加工轨迹能够使得叶片轮廓截面精度较好地满足加工要求,提高了叶片型面的表面质量和精度,证实了该方法的有效性和实用性.本文提出的轨迹规划方法可科学合理地控制曲面预期加工允差,解决了在自由曲面砂带磨削过程中因接触轮尺寸参数选择不当而引起的局部干涉的计算难题,能够有效提高砂带磨削加工的效率和精度.
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