【作者】 赵绪平；

【导师】 段振云；

【作者基本信息】 沈阳工业大学 ， 机械制造及其自动化， 2006， 硕士

【摘要】 数控加工技术是现代自动化、柔性化及数字化生产加工技术的基础与关键技术。因此提高数控加工的效率已经成为当今机械行业的重要研究课题之一,通过计算机建立优化系统,自动优化出切削参数,以达到提高生产率、降低生产成本的目的。 由于在数控加工过程中,特别是复杂曲面加工过程中,切削条件不是一成不变的,但在目前的数控加工中大都是人为的选择保守的切削参数,并且在加工过程中保持切削参数不变,从而大大降低了数控机床的生产效率。 针对加工过程中切削参数变化较大的复杂零件数控加工参数优化问题,采用矩阵网格离散仿真算法,该算法用矩阵网格表示被加工零件的表面形状;并给出常用铣刀加工中网格点切削运算的计算公式;根据刀位文件计算出刀具在相应刀位点的背吃刀量,再由背吃刀量的变化情况将加工路径离散,将连续问题转化成离散问题,将变参数优化问题转化成多参数优化问题;并在各个离散的路径段按照定参数方法进行优化,建立了相应的数学优化模型;根据优化目标函数以及设计参数的性质,将多参数优化问题分解成若干独立的子问题,以简化问题的求解;同时编制出优化程序,并借助计算机运算,最后确定出该路径段的最佳切削参数。由于整个零件的加工过程可由若干个这样的路径段组合而成,因此通过对各个路径段的参数优化实现对整个加工过程的参数优化。 提出一种切削加工变参数优化的方法,采用该方法获得的切削参数能有效地提高加工效率,将工艺人员从大量的手工重复劳动中解放出来,并实现切削参数选取的科学化、合理化、规范化,为企业创造出良好的经济效益。更多还原

【Abstract】 Technology of NC machining is the base and key of modern automatic, flexible and numeric machining technology. It is an important research subject in modern mechanical industry to improve the efficiency of numerical control process. The intent of this article is to present the way to improve productivity and reduce productive cost by setting up optimization system to achieve reasonable machining parameters.In process of NC machining, especially in process of machining complex surfaces, the cutting conditions can change. However, cutting parameters are still chosen artificially and remain unchanged in present process of NC machining, which causes the decrease of NC machine productivity.According to the optimization of NC parameters of complex parts with great change in NC manufacturing, the method to discrete simulation is used in this paper. Shape of the work piece is subdivided into uniform meshes and the depth of each cell being machined by the milling cutter is calculated. The cutting depth of the cutter in corresponding cutter spacing is figured out with the cutter spacing files. Then the process route is dispersed with the change of the cutting depth, and each process route segment is optimized according to steady parameters method. The continuous varying parameter optimization problem is transformed to discrete multi-parameter optimization problem and the corresponding model is constructed. Then the multi-parameter optimization problem is rapidly solved by decomposing it to many sub-problems. At last the math optimized model is established, and the optimized program is compiled which is operated in PC in order to determine the best cutting parameters in this route. In the machining process of the part there are several such routes, so the globally optimized parameters can be achieved by optimizing each route.In this paper, the optimization of varying machining parameters for NC cutting operations is discussed. It can improve the efficiency effectively. Using the method a great deal of technologists could be released from the repeated handwork, and rationalization andstandardization of cutting parameters will be realized, productivity of the machining center can be improved and well economy benefits should be obtained consequently.更多还原