共查询到18条相似文献,搜索用时 295 毫秒
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在金属切削中加工尺度较小时,材料的尺寸效应、材料强化对流动应力的影响及毛刺的存在会严重影响已加工表面质量及尺寸精度,甚至会导致工件报废。基于应变梯度理论,通过子程序嵌入到ABAQUS软件中,构建二维多晶切削模型来探究不同刀具结构对毛刺形成的影响,并清楚观察到晶粒的塑性流动及变形过程。在对该模型的可行性进行验证后展开模拟分析发现,随着刀具前角的增大、切削刃钝圆半径的减小及倒角长度和倒角角度的减小,出口毛刺尺寸均会减小,而刀具后角的变化对毛刺尺寸影响极小,本研究为毛刺的控制及已加工表面质量的提高提供了新的思路。 相似文献
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金属切削毛刺专家知识系统的开发 总被引:2,自引:0,他引:2
毛刺是金属切削加工中产生的常见现象。研究开发出了金属切削毛刺专家知识系统,为管理切削实验所测的毛刺数据、查询毛刺类型与尺寸、优化选择加工参数和进行切削毛刺形成的动力学仿真等奠定了基础。进而,为实现切削毛刺的预报与控制开辟了新途径。 相似文献
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针对金属切削加工中影响工件尺寸精非线性因素从多、精确数学难以建立的特点,提出金属切削加工尺寸精度控制的模糊智能化方法,设计了自寻优模糊控制器,实现了工件尺寸在线智能监控,试验仿真结果表明,这种控制器具有很好的鲁棒性,获得了满意的控制效果。 相似文献
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国外关于切削毛刺生成机理与去除技术的研究 总被引:2,自引:0,他引:2
<正> 一、抑制和减小切削毛刺的必要性随着宇航事业的发展,对切削加工精度要求越来越高,某些特殊零件的加工精度要求在1μm或0.5μm以上。这就使得在切削加工精度要求不太高时产生的切削毛刺被认为其影响可以忽略的传统认识到受了挑战。对大多数设加工工件加工工时统计分析数字表明,去除毛刺工序所用工时约占全部加工工时的5~10%。1973年前后,美国用于去除毛刺的费用大约每年为60亿美元。尤其在数控机床和全自动化流水线的加工中,去除毛刺的 相似文献
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贾春玉 《中国制造业信息化》2000,29(6):48-50
针对金属切削加工中影响工件尺寸精度非线性因素众多 ,精确数学模型难以建立的特点 ,提出尺寸加工精度控制的模糊智能化方法 ,设计了自寻优模糊控制器 ,实现了工件尺寸精度在线智能监控。仿真试验结果表明 ,这种控制器具有很好的鲁棒性 ,获得了满意的控制效果。 相似文献
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Influence of size effect on burr formation in micro cutting 总被引:3,自引:1,他引:2
Tao Zhang Zhanqiang Liu Chonghai Xu 《The International Journal of Advanced Manufacturing Technology》2013,68(9-12):1911-1917
Burr is an important character of the surface quality for machined parts, and it is even more severe in micro cutting. Due to the uncut chip thickness and the cutting edge radius at the same range in micro cutting process, the tool extrudes the workpiece with negative rake angle. The workpiece flows along the direction of minimum resistance, and Poisson burr is formed. Based on the deformation analysis and experiment observations of micro cutting process, the factor for Poisson burr formation is analyzed. It is demonstrated that the ratio of the uncut chip thickness to the cutting edge radius plays an important role on the height of Poisson burr. Increasing the uncut chip thickness or decreasing the cutting edge radius makes the height of exit burr reduce. A new model of micro exit burr is established in this paper. Due to the size effect of specific cutting energy, the exit burr height increases. The minimum exit burr height will be obtained when the ratio of uncut the chip thickness to the cutting edge radius reaches 1. It is found that the curled radius of the exit burr plays an important role on the burr height. 相似文献
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Y.J. Kim J.H. Kim S.L. Ko B.K. Kim 《The International Journal of Advanced Manufacturing Technology》2006,29(9-10):879-884
The exit burr generated in the face milling operation at the edge of the workpiece usually requires deburring processes to enhance the level of precision of the parts. This paper is to geometrically understand the formation of the exit burr in the face milling operation on the arbitrary shaped workpiece with multiple feature such as hole, spline, and arc so that we can suggest the cutting conditions and tool path to minimize the burr formation on the given workpiece in the early design stage. The burr formation mechanism in each type of burr is classified based on the experimental results. A database is developed to store and predict burr formation results. A Windows based program is developed with the algorithm including three steps, i.e., the feature identification, the cutting condition identification, and the analysis on exit burr formation. We can predict which portion of the workpiece would have the exit burr in advance so that we can manage to find a way to minimize the exit burr formation in an actual cutting. Here, the idea of critical burr length is introduced as a criterion in optimization. 相似文献
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金属切削中的毛刺是切削加工中产生的常见现象,它严重地影响产品的精度和使用性,有必要对毛刺的预测进行深入的研究。本文针对铣槽时产生的出口毛刺高度进行试验与检测,并通过田口直交表进行统计分析,对检测到的试验数据运用相关公式进一步进行计算优化,然后根据传统的经验值与优化计算的数据进行比较,获取了以毛刺高度为控制对象的切削用量优化值,以此为依据提出在加工过程中夹具、机床等相关的数据优化,为进一步对毛刺控制的非线性数学模型的建立提供试验数据。 相似文献
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Tristan Régnier Bertrand Marcon José Outeiro Guillaume Fromentin Alain D’Acunto Arnaud Crolet 《Machining Science and Technology》2013,17(6):925-950
AbstractRequirements on burr height and burr amount on machined parts are getting stricter. This leads to method development from manufacturing companies to predict burr distribution and its size along part edges. A deeper understanding of burr formation mechanisms will assist to more accurate model development. This study aims to analyze the exit burr formation, which is formed during orthogonal cutting of a brittle cast aluminum alloy. A customized digital image correlation (DIC) system with the help of a high-speed camera was used to measure the displacements fields. It calculates strain fields during burr initiation and development in orthogonal cutting of T7 heat-treated cast aluminum alloy ENAC-AlSi7Mg0.3 as well. Those results are then qualitatively compared with a numerical model of the burr with chamfer formation developed and simulated using a finite element method, to ensure a good correspondence between experiments and simulation. This model is used to complete the DIC study of burr with chamfer formation mechanisms during crack propagation leading to chamfer formation. The analysis of numerically obtained stress triaxiality fields and of DIC observations from experiments are compared to the assumptions made from analytical models. Finally, necessary improvements of an existing burr formation analytical model are proposed. 相似文献
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针对传统金属带锯床锯切大型圆环类工件存在的锯切效率低、精度差和能耗高的问题,研究设计了一种新型高效锯切系统。不同于传统锯架进给锯切方式,所设计的大型圆环类工件的锯切系统采用工件进给锯切方式。分析了该锯切系统的主要组成以及工作原理,特别对工件旋转装置进行了详细设计;基于西门子300系列PLC,设计了该锯床的电气控制系统;此外,基于经典锯切负载模型,通过对锯切过程中参与锯切齿数的分段计算,建立了该系统的锯切负载数学建模,并进行了Matlab仿真研究。研究结果表明:切削进给方式改变后,所设计的锯切系统不仅锯架体积较小,而且锯切效率、精度、能耗以及带锯条使用寿命等指标较传统带锯床都有大幅度提升。 相似文献
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系统概括了国内外时金属切削毛刺的预报预测研究现状,分析了有限元法在毛刺形成过程、形态度尺寸大小和界限转换条件的定量或定性预测预报中的具体应用,为系统深入地研究切削毛刺提供了理论基础. 相似文献
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金属切削变形本构方程的研究 总被引:5,自引:2,他引:3
金属切削过程的本构关系与应变、应变率、温度等多种因素有关,建立切削变形区内工件材料的本构方程是研究切削变形的关键。本文在文献综述的基础上,首先给出金属切削本构方程的试验研究方法,然后给出金属切削工件材料的典型本构方程,并给出Usui本构方程中不同工件材料的特性系数,以及同一工件材料AISI52100(HRC62)的不同本构方程。经对比分析可见,金属切削过程中变形区内的应力—应变关系除与试验方法、切削条件有关外,还与工件材料的组分和微观晶格结构密切相关。本文最后分析了金属切削变形本构方程研究中存在的问题,并指出发展趋势。 相似文献