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对圆环面刀具五坐标数控加工复杂曲面编程方法进行了综述,指出大多数算法仍采用仅适用于点接触加工的以局部微分几何为基础的刀位算法。本文证明了这些算法的缺陷,提出了一种针对圆环面刀具的五坐标数控宽行加工复杂曲面的刀位计算的思想。 相似文献
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五坐标数控加工的理论误差分析与控制 总被引:18,自引:2,他引:16
对五坐标曲面加工中由离散线性运动逼近理想刀具轨迹所引起的理论加工误差进行了较严格的分析。基于五维线性包络运动分析,得出了适用于多种类型刀具的加工误差估计的通能表达式。该误差是三维意义下较严格的刀具包络成型误差,综合考虑了零件表面的局部几何形状、刀具的形状尺寸与刀轴控制参数、走刀进给方向、机床旋转/摆动机构参数以及走刀步长的影响。在此基础上,分析了减小加工误差的措施,给出了能较严格满足给定精度要求的走刀步长估计算法,有效控制加工误差并提高刀具轨迹质量。 相似文献
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从数控编程的后处理任务出发,以特定五坐标机床C.B.Ferrari 为研究对象,以机床编程手册为参考,以刀具路径模拟软件Plo3d为研究及模拟工具,阐述了五坐标数控机床控制系统E500的数控程序坐标计算方法. 相似文献
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复杂自由曲面五坐标刀位优化问题一直是数控加工领域的一个热点问题,该问题的解决对于显著提高国防和民用工业中重要零件的加工质量和加工效率具有重要意义。Hermite27位算法和MPM算法是国际上最近提出的2种最先进的五坐标27位优化算法。作者给出了2种算法的完整数学模型,将Hermite算法与MPM算法进行了比较研究,从理论上对2种算法解的一致性进行了证明,对2种算法求解过程的重要差别进行了比较,对Hermite算法的求解过程进行了改进,并通过2个实例验证了所提出的改进算法的可行性。 相似文献
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自由曲面数控加工刀具的研究 总被引:5,自引:0,他引:5
对自由曲面数控加工中的刀具进行了较深入的研究。从刀具有效半径和切削速度的角度,对平头立铣刀在五坐标自由曲面加工中的加工效率与切削性能进行了分析。提出了球头刀和平头刀的刀位计算方法,并对叶片曲面的刀具轨迹进行了仿真模拟。 相似文献
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平底刀最优刀轴矢量规划算法 总被引:1,自引:0,他引:1
在进行自由曲面平底刀五轴数控加工刀轴矢量规划时,现有算法多以材料去除率最大作为优化目标,然而加工效率最高的刀轴矢量不一定是刀具最优姿态,还需要综合考虑加工质量、刀轴光顺等因素。从这几个方面建立单个刀轴矢量和相邻刀轴矢量光顺性的度量指标,并以归一化度量指标加权和最小作为优化目标建立刀轴矢量优化模型,经理论分析将多目标规划问题转化为力学平衡问题,弹簧模型中高斯球面上运动节点的平衡位置就是最优刀轴矢量。仿真结果表明SE权因子影响加工效率,DW、DM权因子影响机床运动平稳性,DF权因子影响切削条件,选择合适的权因子可以获得材料去除率大、加工效率高以及在工件坐标系、机床坐标系和进给坐标系下光顺的刀轴矢量。 相似文献
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五轴加工奇异区域内的刀具路径优化 总被引:3,自引:0,他引:3
针对五轴加工在奇异区域内由于旋转轴运动的剧烈变化导致非线性误差过大并对工件、刀具和机床部件造成损害等问题,给出一种奇异区域内加工路径的优化方法。以AC双转台五轴联动数控机床为研究对象,在反向运动学变化中根据正弦、余弦三角函数的周期性对C轴转角进行初次优化;按照加工是否通过奇异点两种情况,采用设定奇异点处的C角值或者修改奇异点附近的刀轴方向两种方法,进一步降低C轴过大转角;以当前加工区间的非线性误差是否超过允许值为判断条件,对仍然不满足精度要求的区间进行递归插值处理。仿真试验和实际加工结果表明,与单纯采用线性插值方法相比,该方法在提高奇异区域内加工精度的同时,有效减少新插入点的数量,从而尽量降低加工速度的损失。 相似文献
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Determination of Cutter Orientation for Five-Axis Sculptured Surface Machining with a Filleted-End Cutter 总被引:5,自引:2,他引:3
Y. Zhong J. Zhou T. Chen 《The International Journal of Advanced Manufacturing Technology》2002,20(10):735-740
In this paper, an accurate and efficient method is proposed for determining filleted-end cutter orientation based on surface
analysis. With this method, the surface geometry is first analysed and classified according to its shape. Different kinds
of surface shape require different treatments with regard to cutter orientation, so that the local geometry of the filleted-end
cutter is matched with that of the surface as closely as possible without gouging the surface in the local region of the cutter
contact points. The proposed method has been successfully implemented using the visual C ++ language and the ACIS geometric modeller. Finally, some illustrative examples are given.
ID="A1"Correspondance and offprint requests to: Dr T. Chen, CAD Centre, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan,
Hubei 430074, PR China. E-mail: tc29@chinese.com 相似文献
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Geometrical Error Analysis and Control for 5-axis Machining of Large sculptured surfaces 总被引:1,自引:2,他引:1
Si-Jie Yan Ji Zhou Fan-Yu Peng Yun-Fei Zhou Xi-De Lai 《The International Journal of Advanced Manufacturing Technology》2003,21(2):110-118
One of the important tasks in five-axis machining of large sculptured surfaces is to control and reduce the machined errors.
This paper presents the methods to control geometrical errors based on the establishment of the link between geometrical errors
and the parameters of tool path planning. Nonlinear errors, which are the majority of geometrical errors during five-axis
machining, are is strictly analysed and formulated. An adaptive step length method is proposed to control effectively the
cutter contact path error. The measures to reduce the scallop error in machining of the large sculptured surfaces are discussed
also. With the combination of this research with CAM software, both large Kaplan and Francis hydroturbine blades have been
successfully machined. It shows that the machined errors can be controlled effectively and the machining efficiency can be
improved in the machining of the large sculptured surfaces by the proposed methods. 相似文献
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复杂曲面五坐标数控加工刀具轨迹的规划算法 总被引:16,自引:6,他引:16
提出了复杂曲面五坐标数控加工刀具轨迹的规划算法。该算法在保证刀具不与被加工曲面发生干涉的基础上 ,使得刀具扫描面与被加工曲面在刀触点处切平面上每个方向的曲率相匹配 ,由此规划的等残留高度刀具轨迹能改善曲面加工精度和加工效率 相似文献
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Five-Axis NC Machining of Sculptured Surfaces 总被引:6,自引:2,他引:4
Yu Wang Xiaowei Tang 《The International Journal of Advanced Manufacturing Technology》1999,15(1):7-14
This paper presents a new method for the determination of tool position and orientation for NC milling of sculptured surfaces
with a five-axis NC machine. This method uses an analysis of local curvatures of the surface and the tool geometry. Based
on matching these local properties, optimal tool axis orientations are selected so that the gouging error in machining is
eliminated or controlled within a specific tolerance. An accurate technique is also proposed for the computation of cusp height
of the machined surface. By eliminating gouging and controlling scallops within a specified tolerance, it is expected that
the time-consuming manual grind-ing process could be greatly reduced or completely eliminated in the finish machining of complex
die or mould surfaces. 相似文献
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对自由曲面的数控加工,寻求最优的刀具轨迹生成方法至关重要.本文基于开源3D库Open CASCADE(OCC)和编程开发环境Microsoft Visual Studio 2010(VS2010),应用B样条表达的自由曲面,采用投影法思想,研究重用已有相似刀具路径方法,提出了处理自由曲面的NC刀具轨迹映射算法.... 相似文献
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Chih-Hsing Chu Jang-Ting Chen 《The International Journal of Advanced Manufacturing Technology》2006,29(7-8):707-713
This paper presents a novel approach that automatically generates an interference-free tool path for five-axis flank milling
of a ruled surface. A boundary curve of the machined surface is subdivided into curve segments. Each segment works as a guide
curve in the design method for developable Bézier surface that controls a developable patch for approximating the surface
with available degrees of freedom. Geometric algorithms are proposed for calculating consecutive patches with G1 continuity across the patch boundary. A tapered tool can move along the rulings of these patches without inducing local tool
interference as a result of their developability. The machining deviation is controlled by the surface approximation error.
A machining test is conducted with the generated CL data and the result verifies the feasibility of the proposed approach.
This work successfully transforms avoidance of tool interference into a geometric modeling problem and provides a simple solution.
It thus demonstrates a good potential for the developable surface theory of five-axis flank machining . 相似文献
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一种支持型腔粗加工刀具序列高效优化的刀具筛选方法 总被引:2,自引:0,他引:2
型腔加工是现代数控加工中广泛面临的一类加工问题。刀具筛选是型腔粗加工刀具序列优化过程中的一个重要环节。现有的基于几何、设备和工艺等约束的刀具筛选方法并不能判别因刀具之间相互制约而产生的冗余刀具,降低了刀具序列优化的效率。通过对比刀具组合过程中因不同刀具的优势互补而产生的效益增量与因换刀带来的相关效益损失量,建立一种用于判断刀具序列是否有效的分析模型;在此基础上,从刀具序列的组合形态的角度构造并证明一种可以判别部分冗余刀具的规则,并将其与基于几何、设备和工艺等约束的刀具筛选方法相串联,得到一种可支持刀具序列高效优化的刀具筛选方法;研究新方法的实现技术,包括刀具加工能力的估算方法和刀具组合有效性的计算方法;算例结果表明所提方法在去除冗余刀具上的效果明显,能为刀具序列的高效优化提供有效支持。 相似文献