共查询到19条相似文献,搜索用时 156 毫秒
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对发动机叶片在现有夹具定位下的螺旋铣削加工状态进行了研究,建立了基于瞬时铣削力的叶片变形模型,提出了基于加工表面静态误差预测、补偿的离线多层次误差补偿方案,利用有限元模拟技术结合铣削力模型,迭代求解各个刀位点处的弹性让刀变形量,据此修正原始的数控刀具轨迹代码,达到消除加工变形误差的目的;并通过有限元ANSYS仿真,得到实时误差补偿刀位轨迹,通过实验验证补偿方案的正确性和实用性。 相似文献
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航空航天复杂薄壁件在数控铣削的过程中,由于实际加工结果与理论尺寸的不一致,导致了加工误差的存在,从而降低了零件的精度,进而直接影响其使用性能。针对航空发动机薄壁叶片在加工时产生的以弹性变形为主的综合误差,研究了航空发动机薄壁叶片加工误差补偿迭代学习建模方法。基于弹性变形理论、泰勒展开建立误差补偿模型,根据前次加工后的数据通过学习迭代算法,计算出下一次切削误差补偿量并重构叶片模型,生成新的数控加工程序,最终使加工误差满足公差要求。通过迭代学习算法对补偿模型的计算,可以有效减少补偿次数,提高补偿加工效率。 相似文献
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《计算机集成制造系统》2017,(9)
为避免薄壁深腔零件侧壁加工过程中因铣削力引起的让刀变形而导致加工精度较低的问题,提出一种基于有限元的铣削加工误差仿真算法。考虑工件/刀具系统的让刀变形及工件的回弹变形,计算生成刀齿微元的连续运动轨迹,并基于点的六面体映射算法对材料进行去除,从而得到连续加工过程和加工面上任意点的加工误差及加工面形貌。以某典型薄壁深腔开口框体结构为加工对象进行了仿真分析,通过实验验证了所提仿真方法的准确性。 相似文献
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针对薄壁件数控加工过程中产生的力致变形误差,提出了一种将变形误差预测与误差补偿进行集成的方法。在提出高效的误差计算迭代算法基础上,采用APDL的方式开发了集迭代计算、刀具走刀、材料去除于一体的误差动态仿真程序,实现全过程加工误差的自动计算。借助UG二次开发工具UG/Open开发的应用程序实现了UG和ANSYS之间的数据通信,根据预测变形误差自动修正CAD模型,继而利用UG CAM生成考虑误差补偿因素的加工代码。研究了涉及误差离线预测及补偿的集成方法的多个关键技术。算例表明:误差预测值逼近实验值,精度可靠;集成软件能够自动生成误差补偿的加工代码,实现了误差离线预测和补偿全过程的CAD/CAE/CAM集成,集成程度高。 相似文献
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薄壁盘由于材料刚性较差等原因难以确保零件加工精度,容易引起变形,对此,提出了高温合金薄壁盘复杂零件加工变形控制方法。分析零件加工过程中产生的变形因素,包括夹装方式、刀具性能参数、工件自身因素、机床定位精度不够以及温度控制不佳等;确立所有工序历史误差源集合,生成误差传递矩阵,构建变形误差源诊断模型;针对不同误差源,提出针对性控制方法,通过最小二乘多项式拟合算法计算让刀误差,并对其补偿;通过有限元分析法建立工件几何模型,设立刚度控制函数,弥补工件自身缺陷;针对机床定位精度和温度分别设计控制函数,实现零件加工变形的综合控制。实验结果表明,所提方法明显减少了零件加工变形现象,保证了切削力平稳,提高了零件质量。 相似文献
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Redesigned Surface Based Machining Strategy and Method in Peripheral Milling of Thin-walled Parts 总被引:1,自引:1,他引:0
Currently, simultaneously ensuring the machining accuracy and efficiency of thin-walled structures especially high performance parts still remains a challenge. Existing compensating methods are mainly focusing on 3-aixs machining, which sometimes only take one given point as the compensative point at each given cutter location. This paper presents a redesigned surface based machining strategy for peripheral milling of thin-walled parts. Based on an improved cutting force/heat model and finite element method(FEM) simulation environment, a deflection error prediction model, which takes sequence of cutter contact lines as compensation targets, is established. And an iterative algorithm is presented to determine feasible cutter axis positions. The final redesigned surface is subsequently generated by skinning all discrete cutter axis vectors after compensating by using the proposed algorithm. The proposed machining strategy incorporates the thermo-mechanical coupled effect in deflection prediction, and is also validated with flank milling experiment by using five-axis machine tool. At the same time, the deformation error is detected by using three-coordinate measuring machine. Error prediction values and experimental results indicate that they have a good consistency and the proposed approach is able to significantly reduce the dimension error under the same machining conditions compared with conventional methods. The proposed machining strategy has potential in high-efficiency precision machining of thin-walled parts. 相似文献
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为实现在加工过程中对薄壁件侧铣产生的较大切削变形进行在线控制,提出基于有限元数值模型和进给速度优化的在线控制策略。根据薄壁件切削过程的有限元仿真结果,建立数控机床进给速度、切削力、工件切削变形间的数值模型,进而确定用于控制变形的最优目标切削力。在具有开放式模块化的数控系统平台上开发了切削力信号实时采集、滤波功能和基于Brent-Dekker算法的进给速度在线优化策略,并根据滤波后的切削力及相应算法在加工过程中实时调整机床进给速度,保证切削力逐渐接近最优控制目标而实现切削变形的在线控制。试验结果表明,经过进给速度在线优化后的切削过程可将薄壁件侧铣变形控制在规定范围内,同时提高了切削效率。 相似文献
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航空薄壁件的刀具偏摆数控补偿加工技术 总被引:4,自引:1,他引:4
航空工业中广泛使用薄壁结构零件,但是由于零件结构复杂、壁薄、精度要求高、加工工艺性差,在切削力、装夹力等因素的影响下,易发生加工变形,很难保证加工质量.由此,本文在有限元分析的基础上,提出了刀具偏摆数控补偿加工方案.实验结果证明,该方法可以在满足加工质量要求的同时,减少加工时间,提高加工效率,是一种方便、高效的加工方法. 相似文献
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薄壁件加工变形控制快速仿真平台开发 总被引:1,自引:0,他引:1
为控制薄壁件装夹变形和加工变形,建立了集装夹优化、加工变形预测、切削参数优化及误差补偿功能为一体的快速仿真平台.在平台实现中,装夹方案的优化采用基于形位公差控制的方法,通过多种装夹方案的比较,确定优化方案.加工变形预测时考虑了前-层变形对后-层切削深度的影响,并使切削力和加工变形达到动态平衡.为获得优化切削参数,建立了以变形控制为目标的优化模型.采用有限元法计算加工变形,采用遗传算法求解优化模型.为解得优化补偿量,仿真时考虑了变形与力的耦合效应.完成了基于ABAQUS的快速仿真平台开发.以镜座零件为例进行仿真,求得了优化的装夹方案和切削参数,验证了平台的可行性. 相似文献
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在航空航天工业等行业中,对于复杂薄壁曲面零件,极易产生由工件变形引起的加工误差,这直接影响了零件的加工精度及表面质量。本文研究了薄壁叶片型面精加工切削过程中工件变形对加工精度的影响:首先利用正交试验求出球头铣刀的铣削力公式,进而结合有限元方法,编写柔性切削变形迭代算法,计算出薄壁叶片的最终变形量,并分析了叶片的变形规律,这对提高叶片加工精度具有重要的实际应用价值。 相似文献
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During the machining process, cutting forces cause deformation of thin-walled parts and cutting tools because of their low rigidity. Such deformation can lead to undercut and may result in defective parts. Since there are various unexpected factors that affect cutting forces during the machining process, the error compensation of cutting force induced deformation is deemed to be a very difficult issue. In order to address this challenge, this article proposes a novel real time deformation error compensation method based on dynamic features. A dynamic feature model is established for the evaluation of feature rigidity as well as the association between geometric information and real time cutting force information. Then the deformations are calculated based on the dynamic feature model. Eventually, the machining error compensation for elastic deformation is realized based on Function Blocks. A thin-walled feature is used as an example to validate the proposed approach. Machining experiment results show that the errors of calculated deformation with the monitored deformation is less than 10%, and the thickness errors were between ?0.05 mm and +0.06 mm, which can well satisfy the accuracy requirement of structural parts by NC (Numerical Control) machining. 相似文献
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零件加工是当下机械加工行业中的重要组成部分,而薄壁零件的数控车削加工更是零件加工中的重点与难点,为了更进一步保证薄壁零件的加工质量,有关人员一定要充分了解影响薄壁零件加工精度的因素,并不断研究有效提升薄壁零件数控车削加工工艺的措施.最后,有关人员更要进一步通过薄壁零件数控车削实例,来充分掌握其加工工艺. 相似文献
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Yu Wei X. W. Wang 《The International Journal of Advanced Manufacturing Technology》2007,33(3-4):260-265
Aerospace thin-walled parts have a complex structure and high accuracy. Factors such as original residual stress, fixing,
and machining may make low-rigidity parts deform easily, which is difficult for traditional craftwork to forecast and control.
Especially in machining big aerospace parts, original residual stress has a great effect on machining deflection. In this
paper finite element model of original residual stress is established to analyze the corresponding deflection by machining
aerospace thin-walled parts. Simulation results are validated consistent with experimental results approximately. At last
the paper puts forward the corresponding mend methods to control the deflection caused by original residual stress during
the actual machining process. 相似文献