低速走丝电火花线切割机导丝嘴位置算法的研究

介绍了低速走丝电火花线切割机二维和三雏直纹面的加工方法，详细讨论了以4轴联动方式加工带锥度型面的三雏直纹面时，由工件下表面的加工轨迹和电极丝的倾斜角度推算上导丝嘴和工作台运动轨迹的方法。     

用椭圆偏置法计算线切割直纹面加工的电极丝中心轨迹

提出了直纹面线切割加工中用椭圆偏置法计算电极丝中心轨迹的方法，并用仿真实例验证了该方法的有效性。     

大锥度线切割加工电极丝中心轨迹的一种线性化方法

介绍了使用"广义电极丝模型"求取大锥度线切割加工工件上下表面电极丝中心轨迹的方法。结合仿真实例研究了轨迹的特点,仿真结果表明:轨迹为非规则曲线,为了提高编程精度,必须对轨迹进行线性化。在此基础上,提出了用二次高分辨率采样方法线性化电极丝中心轨迹,给出了方法的实现流程,并通过仿真验证了该方法的正确性。     

电火花线切割机数控装置的直纹面编程与插补

为解决加工直纹面模具的难题，本文提出考虑使用高速走丝电火花线切割机，并给出其数控装置的直纹面编程方法和插补原理，且结合上圆下方体实例进行了说明。     

电火花线切割机数控装置的直纹面编程与插补

为解决加工直纹面模具的难题，本文提出考虑使用高速走丝电火花线切割机，并给出其数控装置的直纹面编程方法和插补原理，且结合上圆下方体实例进行了说明。     

电火花线切割锥度加工编程技术的研究

分析了电火花线切割加工中常规锥度对应点的计算和电极丝的间隙补偿问题,将上、下表面的加工轨迹转化为对应的XY和UV平面的加工轨迹,用Visual C 实现常规锥度工件轨迹的生成,将锥度工件偏移补偿后得到的电极丝中心轨迹转化为工作台在XY平面和上导向器在UV平面的控制轨迹.实现线切割机锥度加工中的4轴联动加工技术.     

基于原位检测的类直纹面整体式叶轮高效侧铣加工技术研究

提出了一种基于原位检测的类直纹面整体式叶轮曲面的侧铣加工方法。将类直纹面重构为近似直纹面,提出了类直纹面整体式叶轮可侧铣的判定条件;针对非可展直纹面刀轴矢量的求解方法,给出了解析算法;最后对类直纹面叶轮五轴刀路进行了仿真并进行了实际数控加工实验,验证了该算法的正确性。     

电火花线切割CAD/CAM集成系统的研究

研究了电火花线切割CAD/CAM集成系统。首先建立本系统的几何模型内核 ,之后重点介绍了电火花线切割自动编程中电极丝中心轨迹的计算方法 ,即电极丝半径的二维和三维补偿方法 ,最后用OpenGL图形工具库进行了电极丝轨迹验证程序的设计。     

电火花线切割拐角加工精度的实时预测

提出了一种电火花线切割加工拐角加工精度的实时预测方法,并为此建立了实时预测系统.系统根据实时采集的放电能量等加工参数,通过电极丝振动解析及数控轨迹与电极丝位置关系的分析,可得出电极丝形变量与加工误差,从而可将拐角加工形状实时地再现于计算机上,实现了拐角加工精度的实时预测.     

线切割加工模具的工艺要点分析

针对电火花线切割的工艺特征，分析加工过程中电极丝偏移量产生的原因。介绍了线切割数控编程中电极丝中心线实际走丝轨迹的计算原则和方法，提出穿丝孔的确定与切割路线的优化方面的工艺优点。并就线切割加工中模具零件的特殊工艺情况，提出相应的工艺措施，以改善模具的加工精度和制造质量，及提高生产效率。     

Improved positioning for side milling of ruled surfaces: Analysis of the rotation axis's influence on machining error

This article covers side milling of ruled surfaces using a milling cutter. Flank milling is useful for machining objects such as impellers, turbine blades, fan vanes and all workpieces defined by non-developable, ruled surfaces. In the present article, the influence of parameters defining improved positioning described in a previous study will be appraised. The general idea with improved positioning is to position the milling cutter at a tangent to the 2 directrices of the ruled surface while keeping a point of contact between the milling cutter and the rule considered. This is obtained by a rotation at a point about an imposed axis. Having defined calculation of error between the milled surface and the nominal surface, the influence of the point and the axis of rotation of improved positioning on error will be studied. From this, optimum improved positioning parameters allowing minimisation of error between the ruled surface and the milling cutter will be deduced.     

Machining accuracy improvement in five-axis flank milling of ruled surfaces

The aim of this study is to develop a new adjustment method for improving machining accuracy of tool path in five-axis flank milling of ruled surfaces. This method considers interpolation sampling time of the five-axis machine tools controller in NC tool path planning. The actual interpolation position and orientation between G01 commands are estimated with the first differential approximation of Taylor expansion. The tool swept volume is modeled using the envelope surface and compared with the design surface to determine the deviation, which corresponds to the machining error induced by the linear interpolation. We propose a feedrate adjustment rule that automatically controls the tool motion at feedrate-sensitive corners based on a bisection method, thus limiting the maximum machining errors and improving the machining accuracy. Experimental cuts are conducted on different ruled surfaces to verify the effectiveness of the proposed method. The result shows that it can enhance the machining quality in five-axis flank milling in both simulation and practical operation.     

基于误差分析的复杂曲面可侧铣判定方法研究

基于复杂曲面侧铣加工误差计算,提出了一种曲面能否通过侧铣实现高精度加工的判定方法,该方法适用于任意直纹和非直纹曲面。侧铣加工误差为待加工理论曲面与刀具运动包络曲面之间的距离,在此基础上,应用整体最优刀具路径下的最大几何偏差进行曲面可侧铣判定依据。数值仿真算例表明:该方法不仅能够有效地判定曲面能否侧铣,同时能够输出满足误差要求的最优刀具路径,加工实验也表明该方法能够极大地提高加工效率。     

An algorithm for surface design and tool path generation in wire-cut electrical discharge machining

This paper proposes a CAD/CAM mathematical foundation to design ruled surfaces for wire-cut electrical discharge machining (EDM). This method combines the boundary planes concept, the coordinate representation of lines, control lines and design function to generate free form ruled surfaces. The tool motion and offset surface can also be generated simply by the same approach for computer numerical control (CNC) wire-cut EDM. The algorithm, being different from conventional methods, can present a surface or tool path concisely and uniquely. A numerical example is given to illustrate the proposed approach.     

Simulation of flank milling processes

The paper presents prediction of cutting forces when flank milling ruled surfaces with tapered, helical, ball end mills. The geometric model of the workpiece is imported from standard CAD systems, and the tapered helical ball end mill is modeled as the combination of sphere and cone primitives in ACIS^© solid modeling environment. The intersection of cutter and part with a ruled surface is evaluated, and the cutter entry into and exit angles from the work material are modeled, and stored as a function of tool center coordinates along the path. The cutter entry and exit angles, the immersion angles, are used as boundary conditions in predicting the cutting forces along the path. The methodology allows prediction of cutting load distribution on the tool and part, as well optimization of machining cycle times by scheduling the feedrate in such a way that torque, power and static deflections can be maintained at safe levels.     

一种新的高精度快速插补算法--长轴余量法

文章用数学分析对最小偏差法直线插补几何特性进行研究,探讨了一些进给规律,利用这些规律,提出一种新的直线插补算法--长轴余量法,该算法使一步为单位进给变为若干个步为单位进给,使得插补速度明显提高,同时保持插补精度和最小偏差法相同,有效的解决了插补算法中精度和速度之间的矛盾.该算法已经在实际数控系统中得到验证.     

连续变焦系统凸轮槽建模及加工方法优化

在机械补偿连续变焦光学系统中,核心零件曲线套筒变倍凸轮槽和补偿凸轮槽两侧面的加工精度和表面质量直接影响变焦系统在连续变焦过程中能否成像清晰、稳定。采用直纹面加厚的方式完成了凸轮槽建模,且在曲线点阵拟合的过程进行了公差控制。用四轴联动全顺铣的走刀方式,对进、退刀点进行特别处理完成凸轮槽的加工。经过实际加工验证,采用该方法大幅地提高了凸轮槽的加工精度和表面质量。     

电弧增材制造中空间曲面等距路径规划算法

基于曲面分层的增材制造是目前研究热点之一. 相比于平面路径规划,在曲率任意变化的复杂空间曲面上进行路径规划算法研究较少,尤其是等距路径规划算法. 提出了一种基于体素化和曲线积分思想的空间曲面等距路径规划算法,算法主要包括体素化模型、计算体素点到源曲线的测地距离、生成增材路径等步骤. 该算法精度可控,其精度主要由模型体素化密度决定;与扫描线法相比,从根本上避免了平移路径时由于局部和全局自相交生成的无效环,提高了计算效率. 最后,选取3种典型曲面,分别为由平面组成的简单曲面、圆柱曲面、B样条曲面,进行空间曲面等距路径规划,已验证算法的适用性,并在圆筒试件上进行曲面分层GMAW电弧增材验证试验. 结果表明,该算法可以满足电弧增材制造的精度要求.     

基于改进CC路径截面线法的机器人铣削加工刀具轨迹生成方法

机器人铣削加工技术是当前机器人技术发展的重要方向之一,而刀具轨迹的自动生成是实现机器人铣削加工的一个关键环节。以Open Cascade为几何造型技术开发平台,以改进的CC路径截面线法为轨迹生成方法,通过对约束面间距进行动态调整,改进了传统CC路径截面线法刀轨疏密不一致的问题,从而能够提高机器人铣削加工精度。在此基础上,开发出相应的CAD/CAM软件系统,实现了自由曲面精粗加工刀具轨迹的自动生成。最后,通过仿真和实验对生成的刀具轨迹进行了验证,验证了方法的可行性和准确性。     

金刚石线锯切割碳化硅陶瓷的机理与工艺研究

通过金刚石线锯切割碳化硅陶瓷的单因素试验设计,研究线速度、进给速度、进给速度与线速度比值R等工艺参数对其表面质量的影响规律,并通过超景深三维显微镜、精密粗糙度轮廓仪对其表面形貌、表面粗糙度进行观察和测量。结果表明:当线速度从0.4 m/s增加到1.3 m/s时,碳化硅陶瓷的表面形貌明显改善,进给方向和线锯方向的表面粗糙度分别下降了20.35%和10.45%;当进给速度从6 μm/s增加到24 μm/s时,其表面形貌由好转差,进给方向与线锯方向的表面粗糙度分别上升了12.07%和3.91%;当进给速度与线速度增加但两者比值R固定为2×10-5时,碳化硅陶瓷的表面质量基本维持在同一水平。