【作者】 郭强；

【导师】 孙玉文；

【作者基本信息】 大连理工大学 ， 机械制造及其自动化， 2010， 硕士

【摘要】 薄壁件在航空航天领域的应用越来越广泛,但是薄壁件本身的特点决定了它的加工精度难以控制,薄壁件的特点是整体性,面积大,刚度低,加工困难,等等。如何在加工过程中合理的预测出加工变形误差并正确的预测出来,最后加以补偿以达到加工精度要求是现在科研工作者研究的热点。本文在总结前人研究的基础上分析了薄壁件在加工过程中的特点并做了以下工作。首先,建立立铣刀铣削力模型,以正交切削为基础,分析切削力和材料各参数、刀具角度之间的关系,利用正交/斜交化关系并把立铣刀沿着刀轴方向分为若干切削力单元并建立每个单元的切削力,最后建立了立铣刀在切削过程中切削力模型,把次摆线切削刃轨迹转化为圆形轨迹,并计算了切削力计算切削力过程中关键参数,未变形切削厚度。其次,分析了有限元模型建立过程中的应力场和温度场,并采用应力场温度场直接耦合的方式建立了薄壁件加工过程有限元模型。本文建立完成有限元模型后,采用了迭代算法来求解薄壁件加工过程中的变形误差曲线,最后采用插补的方法获得薄壁件在加工过程中的误差曲面。再次,采用三轴和五轴补偿策略分别对误差曲面进行补偿。最后,利用航空铝合金7075-T6进行了加工实验研究,实验结果和预测结果吻合的也很好,同时还做了三轴补偿和五轴补偿的加工试验,结果表明三轴和五轴补偿策略都能降低加工误差,但是五轴补偿更能发挥五轴加工中心的特点和获得更高的精度。更多还原

【Abstract】 In aeronautic/aerospace field, more and more key functional parts or components with sculptured surfaces use thin-walled parts. However, the characteristics of thin-walled parts such as integrity, large area, low-rigidity, hard-machining etc. determined that the precision of them are difficulty to be controlled. How to predict deformation error and compensate it in milling process is a challenge for researchers and manufactures. Based on successful research findings of literatures, this paper analyzes the properties of the milling process and does some works as follows:Firstly, cutting force model for end mill. Based on orthogonal milling process, analyzing the relationships between cutting forces and parameters of materials and the angles of the cutter, the cutting forces on every cutting element using orthogonal/inclined relationship are computed, finally, the total cutting forces impacted on the cutter are obtained, and the key parameters of the cutting force model, instantaneous uncut chip thickness, is computed in this paper.Secondly, analyzing the temperature field and stress field, and the finite element model is set up adopting direct-coupling method, the using the iterative method, the deformation error curves are predicted and finally the deformation error surface is obtained through interpolation method.Then, utilizing three and five-axis compensation method, the deformation surface is compensated.Finally, using AL7075-T6, a series of experiments are executed, the results shows that there are consistent with each other, between experiment data and simulation data, further more, both three and five-axis compensation method can deduce the deformation error, but five-axis compensation method is of more precision and takes full advantage of five-axis machine center.更多还原