曲面轮廓数控铣编程

研究了基于UG NX／CAM模块中固定轴曲面轮廓铣削的CAM原理,通过具体实例讨论了UG NX／CAM固定铣削编程方法、过程及NC程序的生成方法。研究了固定铣数控加工中参数的合理设置方法及其误差的有效控制手段,并得出了相关结论。     

异形面型芯数控加工与仿真研究

随着计算机技术的发展,先进的CAD/CAM软件技术在现代数控技术中的应用越来越广泛。通过运用UG这款先进的综合软件在模具数控加工方面的强大功能,结合典型曲面模具型芯零件,探索了其可变轴联动数控加工程序的一般方法,进行了复杂异形面型芯零件数控加工工艺设计,实现了复杂异形面型芯零件的粗加工、固定轴曲面轮廓半精加工、可变轴曲面轮廓精加工,同时进行了3D仿真验证,通过后处理可以生成实际可执行的可变轴数控加工程序,对实际生产具有较强的借鉴意义。     

基于UG NX 8.0的复杂曲面三维建模及数控加工

基于UG NX 8.0平台,以灯罩这一复杂曲面为例,详细介绍了复杂曲面的造型方法,并研究了UG CAM中平面铣、型腔铣和固定轴曲面铣在复杂曲面三轴数控加工中的应用情况。     

NX技术在模具型芯加工中的应用

结合典型曲面模具型芯零件,探索了其可变轴联动数控加工程序的一般方法,进行了复杂异形面型芯零件数控加工工艺设计,实现了复杂异形面型芯零件的粗加工、固定轴曲面轮廓半精加工、可变轴曲面轮廓精加工,同时进行了3D仿真验证,通过后处理生成了实际可执行的可变轴数控加工程序,对实际生产具有较强的借鉴意义。     

基于UG的螺旋叶片数控五轴加工

为提高螺旋叶片的加工效率和质量,提出了一种新的综合优化方法.以螺旋叶片高效率、高质量、无干涉五轴加工刀具轨迹为目标,采用UG CAM可变轴曲面轮廓铣的曲面区域驱动方法,选择合适的投影矢量方向和刀轴方向,采用合理的加工工艺、切削用量和优化进退刀,采用自定义的后处理文件生成了相应数控系统的数控代码实验结果表明该零件的加工质...     

3+A可变轮廓铣曲面加工

介绍了可变轮廓铣曲面加工策略组合、操作设置,并通过案例进行分析,对5轴数控编程具有重要的指导意义。     

UG可变轴轮廓铣曲面驱动在复杂曲面加工中的应用

需要采用五轴联动加工的部分基本上都是曲面,这些曲面如何编程是最关注的问题。以裸模为载体,利用UG NX9软件,构造驱动曲面,利用可变轴轮廓铣的曲面驱动完成零件的编程,利用DMU80 mono Block五轴镗铣加工中心来进行验证,来讲述这些需要五轴联动加工的复杂曲面的一个编程方法,给其他学习者以借鉴。     

四轴曲面铣削加工

总结归纳了可变轮廓铣曲面四轴加工的6种方式,并对功能参数"曲面百分比"、"前倾角"、"侧倾角"、"旋转角"进行了深入讲解和剖析,这些编程技巧、设置方法可广泛应用于四轴、五轴编程中,可变轮廓铣曲面加工策略能深度拓展四轴机床功能,提升设备加工能力。     

NX软件在异形型面零件数控加工中的应用

针对某复杂异形型面零件,借助数字化设计与计算机辅助制造功能,应用NX软件进行数控加工工艺设计。研究了应用NX软件进行异形型面零件数控加工自动编程的一般方法,进行了型腔铣粗加工、固定轴轮廓铣半精加工、区域轮廓铣精加工、变轴曲面轮廓加工工艺设计,并进行了三维仿真验证,进而通过后处理生成机床可识别的数控加工程序。     

UG固定轴曲面区域轮廓铣在高精度翼片曲面加工中的应用

针对具有高精度曲面翼片类这一典型零件,讨论了固定轴曲面区域轮廓铣在数控程序设计及加工中的应用。以曲面的刀路轨迹设计、工艺方案的选用以及铝合金材料变形的控制等因素为研究重点设计了合理的工艺方案,粗加工采用压板固定,在三轴机床通过一定的工艺流程加工,精加工采用专用工装夹紧在四轴加工中心加工,并详细说明了工艺流程中辅助支承的支承力大小、一夹一顶工装夹具拉应力的转变等问题。重点针对在四轴加工中心应用固定轴曲面轮廓铣,研究了固定轴轮廓铣刀轨原理、固定轴曲面区域轮廓铣实施的流程步骤及固定轴曲面区域轮廓铣在流程步骤中各主要参数设置。固定轴曲面区域轮廓铣较其他驱动方法应用更广泛,灵活性更高,其刀轨下刀点、切削方向、投影矢量方向等更易控制、调整,为四轴加工中心加工翼片类零件曲面提供参考和借鉴。     

旋转阴极展成电解加工的间隙特性及光整直纹面的误差计算

旋转阴极展成电解加工主要用于型面的光整加工，其最终加工间隙决定了型面精度，对进给速度，初始切深，阴极半径这3个影响最终加工间隙的关键因素进行了试验研究，结果表明旋转阴极展成电解加工具有相当好的间隙稳定性和整平能力，并且由于间隙和阴极半径小，用其光整加工直纹面产生的几何误差远小于铣刀加工，对此进行了理论计算。     

模具光整加工技术新进展

从工艺——机械抛光、特种抛光、复合抛光，自动化——数控机床、机器人、知识库、测量，“一次过加工技术”——高频窄脉冲和展成电解加工、混粉电火花镜面加工、高速铣加工三方面对现有的模具抛光技术进行了较为详细的介绍，分析了各自的特点、适用场合及某些技术关键。     

Milling contour error control using multilevel fuzzy controller

Machining contour error plays important roles in product quality. This paper presents an implementation of multilevel fuzzy controller in controlling contour errors while maintaining the desired feed rate of milling processes. The orthogonal global task frame was used to transform the tool positions from the Cartesian coordinate system to the curvilinear coordinate system. Contour error and tracking lag error calculated from the curvilinear coordinate system were used by the multilevel fuzzy controller to drive the machining axis on the Mazak VQC-15/40 vertical machining center. The contour error of the machined work piece measured by the coordinate measuring machine showed that the contour error were significantly reduced and the feed rate were regulated at the desired speed.     

Feedrate optimization for variant milling process based on cutting force prediction

Machining process modeling, simulation and optimization is one of the kernel technologies for virtual manufacturing (VM). Optimization based on physical simulation (in contrast to geometrical simulation) will bring better control of a machining process, especially to a variant cutting process – a cutting process so complex that cutting parameters, such as cutting depth and width, change with cutter positions. In this paper, feedrate optimization based on cutting force prediction for milling process is studied. It is assumed that cutting path segments are divided into micro-segments according to a given computing step. Heuristic methods are developed for feedrate optimization. Various practical constraints of a milling system are considered. Feedrates at several segments or micro-segments are determined together but not individually to make milling force satisfy constraints and approach an optimization objective. After optimization, an optimized cutting location data file is outputted. Some computation examples are given to show the optimization effectiveness. This revised version was published online in October 2004 with a correction to the issue number.     

Flank Wear Estimation in Face Milling Based on Radial Basis Function Neural Networks

This paper presents an estimation of flank wear in face milling operations using radial basis function (RBF) networks. Various signals such as acoustic emission (AE), surface roughness, and cutting conditions (cutting speed and feed) have been used to estimate the flank wear. The hidden layer RBF units have been fixed randomly from the input data and using batch fuzzy C means algorithm, and a comparative study has been carried out. The results obtained from a fixed RBF network have been compared with those from a resource allocation network (RAN).     

Contour parallel milling tool path generation for arbitrary pocket shape using a fast marching method

Contour parallel tool paths are among the most widely used tool paths for planer milling operations. A number of exact as well as approximate methods are available for offsetting a closed boundary in order to generate a contour parallel tool path; however, the applicability of various offsetting methods is restricted because of limitations in dealing with pocket geometry with and without islands, the high computational costs, and numerical errors. Generation of cusps, segmentation of rarefied corners, and self-intersection during the offsetting operations and finding a unique offsetting solution for pocket with islands are among the associated problems in contour tool path generation. Most of methods are inherently incapable of dealing with such problems and use complex computational routines to identify and rectify these problems. Also, these rectifying techniques are heavily dependent on the type of geometry, and hence, the application of these techniques for arbitrary boundary conditions is limited and prone to errors. In this paper, a new mathematical method for generation of contour parallel tool paths is proposed which is inherently capable of dealing with the aforementioned problems. The method is based on a boundary value formulation of the offsetting problem and a fast marching method based solution for tool path generation. This method handles the topological changes during offsetting naturally and deals with the generation of discontinuities in the slopes by including an “entropy condition” in its numerical implementation. The appropriate modifications are carried out to achieve higher accuracy for milling operations. A number of examples are presented, and computational issues are discussed for tool path generation.     

球头铣刀刀具磨损建模与误差补偿

针对刀具磨损度量方式和模型建立的问题,以球头刀具为研究对象,提出球头铣刀刀具磨损的度量方式,建立球头刀具磨损模型.以复映磨损在硬度较软加工材料上的方式测量球头刀具磨损,确定刀具磨损模型系数,给出刀具磨损模型系数确定的具体实现方法.加工试验验证球头刀具磨损度量方式的合理性和所建立刀具磨损模型的正确性,同时针对数控铣削加工中球头铣刀刀具磨损引起的误差提出离线仿真误差补偿算法,给出离线仿真误差补偿算法的具体实现步骤,通过建立的刀具磨损引起的加工误差模型仿真获得加工走刀步的误差.对于误差超差的走刀步,预先修改数控加工(Numerical control,NC)程序,保证实际加工零件满足精度要求.误差补偿验证试验表明所提出的离线仿真误差补偿算法的正确性和有效性.     

高速铣削镍基合金GH4169切削力的试验研究

镍基合金广泛应用于航空航天上,但加工起来比较困难。文中以镍基合金GH4169为试验对象,进行了高速铣削试验,研究铣削速度vc、轴向切深ap、径向切宽ae和进给量f四个切削参数对切削力F的影响,从而为生产实践提供指导。     

基于铣削快速落刀法的切削颤振研究

为改善传统测量方法的局限性,更好地研究铣削过程中的振动规律,设计了一种铣削快速落刀实验方法。通过快速落刀实验,对获取的表面样本进行分析计算,得到铣削的颤振频率,并将其与利用动态扭矩计算得到的颤振频率进行对比,结果表明,快速落刀法完全可应用于高速铣削的颤振研究中。此外,应用铣削快速落刀法初步研究了切削参数对振动的影响。