【作者】 何小妹；

【导师】 赵文珍；

【作者基本信息】 沈阳工业大学 ， 机械电子工程， 2002， 硕士

【摘要】 目前，截面包络法数控加工螺旋面时刀触点和刀位轨迹的计算方法已取得一定成就，但缺少对现有算法和工艺的精度分析和研究。本文在最小有向距离算法的基础上，对无瞬心截面包络法数控加工螺杆时的误差分析方法进行了探讨，并对影响误差的主要因素进行了分析。 从理论上，阐述了无瞬心包络法加工原理和最小有向距离算法的基本理论。在利用最小有向距离算法获得无干涉刀位轨迹的前提下，根据螺旋面的特性，提出已知刀具表面和刀位轨迹，计算实际加工螺旋面的包络面仿真算法。并针对复杂螺杆应从啮合精度来衡量加工精度的要求，提出实际加工表面法向误差分析模型和算法。在法向误差算法中，为寻找过理论点的法线与实际螺旋面的交点，采用切平面投影分析方法，提出象限搜索算法。在C语言环境下对上述算法进行编程，通过实例进行了具体的误差分析。针对螺杆加工中编程点之间刀具的实际运动轨迹为阿基米德螺线的事实，分析了阿基米德螺线插补对加工精度的影响，并在此基础上讨论编程点之间的步长、刀尖圆弧半径和刀具安装角度等因素对加工误差的影响，得出由于阿基米德螺线插补而影响螺杆加工精度的主要因素为工件端截面廓形和编程点之间的步长的结论。采用包络面仿真算法，分析了刀具安装高度误差对螺杆加工精度的影响，提出对于此项误差进行相位补偿和相位补偿角度的概念，将经过相位补偿后的法向误差作为刀具安装高度对加工精度影响的分析依据，总结出误差规律；通过分析认为这些误差产生的根本原因是实际加工的刀位轨迹与计算刀位轨迹不一致，仍属于数控编程误差，为此提出了软件补偿措施。 经过误差分析方法的研究和误差规律的总结，得出影响螺杆加工误差的主要因素，提出提高螺杆加工精度的措施，进一步验证了最小有向距离算法的正确性，完善了复杂表面无瞬心包络加工理论，具有较强的实践指导意义。更多还原

【Abstract】 At present, the calculative method of cutter-contact points and cutter-path when machining helicoids with section envelope principle has been succeeded to a certain extent, but there is lack of the study and method for such arithmetic and technics. So on the basis of the algorithm of seeking minimal orientation-distance, this paper probe into error analysis method for machining spiral rod by non-instantaneous section envelope principle and make analysis for primary influencing factors.Non-instantaneous section envelope machining principle and the algorithm of seeking minimal orientation-distance are expounded theoretically. Non-interference cutter path is gained after the use of the algorithm of seeking minimal orientation-distance. According to the characteristic of helical surface, "the envelope surface simulation algorithm" for calculating actual machining helicoids is put forward at the presupposition of cutter surface and cutter path. Error analysis model and algorithm in the normal direction for factual machining curved surface is set forth in allusion to the demand that for complicated spiral rod machining precision should be scaled from mesh precision. In this algorithm, for seeking the point of intersection between the normal line passed the academic point and the factual machining curved surface, projection analysis method in the tangent plane is used, the quadrant seeking algorithm is brought forward and algorithm is programmed by the programming language C, detailed error analysis with example is done. The influence of Archimedes spiral curve interpolation on machining precision is analyzed, for the fact that the actual cutter path among the programmed points in the machining of spiral rod is Archimedes spiral curve. On the basis of that, the factors such as the step among the programmed points ,the radius of cutter cirque and the fixed angle of cutter are discussed, the primary factors of influencing machining precision are the section profileof work-piece and the step among the programmed points. Using envelope surface simulation algorithm, the influence of the cutter fixed height on the machining precision of spiral rod is analyzed; the concept of compensatory phase angle and compensation for such error on phase are advanced. The normal error after phase compensation is considered as the analysis gist, the rule of error is summarized. By the analysis, the essential reason for error is the non-consistence between the factual machining path and the calculative cutter one. Such error belong to NC programming error, so the compensational measure form software is set forth.By the study on error analysis method and the summarizing of error rule, the primary factors of influencing machining precision of spiral rod are gained, the measure for improving machining precision is elicited. Thus, the correctness of the algorithm of seeking minimal orientation-distance is proved again, the theory of non-instantaneous envelope machining is perfected, the practice guidance is acted on.更多还原