自由曲面砂带磨削轨迹规划与误差控制分析

发布时间：2018-07-03 11:47

本文选题：自由曲面 + 宽行加工　；参考：《工程科学与技术》2017年06期

【摘要】：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。
[Abstract]:Belt grinding is one of the important methods to improve the surface precision and surface quality of free-form surface workpiece. A trajectory planning method for free-form abrasive belt grinding based on machining precision control is proposed. Firstly, the radius of contact wheel without curvature interference and the width of contact wheel satisfying machining tolerance are derived, and the relationship between the principal curvature of wheel and machining point on the surface is combined. The machining tolerance which meets the requirements of free-form surface is selected by genetic algorithm of diploidy, and the contact wheel dimension parameters of non-curvature interference machining are obtained. Then, based on the principal curvature direction of the machining point, the adaptive wide line spacing planning of the machining path is realized. At the same time, the potential large reciprocating and swinging motion of the grinding head in the point lead planning process is processed by the compliance algorithm. The grinding trajectory of the contact wheel at the grinding point is obtained, which is stable in line spacing and meets the requirement of the grinding point, and the contact wheel always fits with the free-form surface at all times. Finally, the trajectory planning of an aeroengine blade profile is carried out by using this method, and the machining verification is carried out on the NC abrasive belt grinder. The results show that the planned grinding track can make the blade profile section accuracy meet the requirements of machining, improve the surface quality and accuracy of the blade profile, and verify the effectiveness and practicability of the method. The trajectory planning method proposed in this paper can scientifically and reasonably control the allowable errors in the expected machining of surfaces, and solve the problem of calculating local interference caused by improper selection of contact wheel dimension parameters in the grinding process of free-form abrasive belt. It can improve the efficiency and precision of belt grinding.
【作者单位】：电子科技大学机械电子工程学院;
【基金】：国家自然科学基金资助项目(51275078) 国家科技重大专项资助(2013ZX04013-011) 中央高校基本科研业务费资助项目(ZYGX2015J086)
【分类号】：TG580.619.2

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