共查询到20条相似文献,搜索用时 845 毫秒
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针对以圆柱面,圆锥面为底面,外轮廓和岛屿轮廓由直线段和圆弧段任意组合而成的曲底多岛屿腔槽的清根加工算法进行了深入的研究,生成了用球头刀5轴清根加工腔槽的内外轮廓与曲底面相交部分的正确的刀位文件。 相似文献
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基于模糊推理的自由曲面描述方法和模式识别理论,提出一种适用于不同刀具类型并可同时考虑无刀具底面干涉刀位和侧面干涉刀位的自动算法。 相似文献
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为解决组合曲面五轴加工问题提出一种基于计算机图形学Z-buffer技术的圆环面刀具刀位生成算法。首先借助Z-buffer技术确定刀位计算的检测区域,然后在保证圆环面刀具和检测区域不干涉的前提下调整刀位,使刀具端面和模型曲面充分贴合,从而得到更宽的加工行宽。算法充分利用计算机硬件的快速高效性,直接对加工检测区域内的点进行读取和存贮,避免复杂的搜索和迭代过程。算法过程中集成对刀位干涉的检测和避让,可直接生成无干涉的刀位数据。刀位算法计算过程使用曲面的多面体信息,适用于以裁剪曲面为元素的组合曲面模型的无干涉刀位的计算。针对某组合曲面模型进行刀位计算和仿真,仿真结果相比传统的球头刀加工算法效率提高了10倍。最后对生成的刀轨进行了实际加工试验验证。 相似文献
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基于散乱数据点的数控加工刀位直接生成 总被引:4,自引:0,他引:4
研究了测量得到的散乱数据点在平面上投影点的边界轮廓提取算法;以抬刀次数最少为优化目标,通过引入计算几何中单调链的概念,确定了最佳的行切加工方向和最少单调链数;给出了在平面区域内行切法加工的刀位计算与Z字形刀位连接方法,该方法适用于模具型腔的刀位规划;针对圆环刀、球头刀和平头刀,提出了不发生干涉的曲面三轴加工刀位计算方法,可基于散乱点测量数据直接生成数控加工刀位,此刀位计算方法也可用于模具型腔的修复。最后,通过数值仿真验证了算法的可行性。 相似文献
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整体叶轮鼓形刀五坐标数控加工刀位轨迹生成 总被引:1,自引:0,他引:1
研究了用鼓形刀具进行整体叶轮五坐标数控加工的编程技术.根据鼓形刀具的几何特点,设计了一种无干涉的鼓形刀刀位轨迹生成算法,开发出整体叶轮五坐标数控加工程序生成功能模块.通过算例,证明设计的鼓形刀无干涉刀位轨迹算法是切实可行的,与球头刀相比,对于同样的残留高度,可以增大加工行距,使刀轨长度变短,可提高整体叶轮数控加工的效率. 相似文献
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Jung-Jae Lee Dr Suk-Hwan Suh 《The International Journal of Advanced Manufacturing Technology》1998,14(11):795-805
Flank milling is the key feature that the five-axis NC machine offers. Compared with bottom-edge based machining (e.g. flat/fillet endmilling), the machinability can be greatly enhanced by flank milling where the side cutting edge is mainly used. As far as tool-path planning is concerned, the conventional method of the cutter-axis parallel to the ruling lines of the generator curves imposes interference problems including overcut/undercut. In this paper, a new interference-free tool-path planning method fortwisted ruled surfaces is presented. Our strategy is to change the tool orientation and offset distance such that the undercut volume is minimised without global tool interference. The validity and effectiveness of the algorithm is demonstrated via several illustrative examples. 相似文献
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基于临界约束的四轴数控加工刀轴优化方法 总被引:1,自引:0,他引:1
针对自由曲面四轴加工中复杂刀具运动导致的干涉和刀具运动不连续等现象,提出一种基于临界约束的刀轴优化方法。基于刀具与工件约束曲面之间的相对位置关系,利用曲线上的点搜索算法确定切触点处的临界刀轴矢量,并计算当前切触点刀轴摆动的可行域;以切削行内所有切触点的刀轴可行域为基础,建立当前切削行内无干涉且相邻刀轴变化最小的刀轴矢量优化模型,实现了自由曲面四轴加工无干涉刀轴矢量的光顺控制。整体叶盘四轴加工试验表明,利用此方法获得的刀轴矢量可以显著改善机床运动的连续性,并避免刀具干涉的产生,提高了加工质量。 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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五轴NC加工中刀具运动包络面的计算 总被引:5,自引:3,他引:2
在机械加工过程中,刀具的铣削在加工体表面形成沟槽,对该沟槽型面的数字化描述是精确计算表面加工残差、判断加工干涉的理论基础,进而可实现表面加工精度评估与控制及加工轨迹全过程的精确规划计算。沟槽型面是刀具刃口回转面在空间运动形成的包络面的一部分,因此推导包络面的解析方程成为解决问题的关键。结合五轴加工机床的运动特点,通过建立加工刀具刃口回转面的数学模型,推导出五轴NC加工刀具运动刃口回转面包络的解析方程。数字仿真的结果与实际完全一致,验证了方法的正确性和有效性,具有较强的理论性和实用价值。 相似文献
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AL-Mokhtar O. Mohamed Robert Bauer Andrew Warkentin 《The International Journal of Advanced Manufacturing Technology》2014,73(5-8):715-725
In this paper, a new grinding wheel grooving system is proposed that is able to both groove as well as re-groove a grinding wheel using a single-point diamond dressing tool. The re-grooving capability of the new system is achieved by synchronizing the grinding wheel angular position with the dressing tool translational position. This position synchronization enables the diamond dressing tip to repeatedly engage the grinding wheel at the same angular position around the wheel and then proceed to trace the existing groove pattern along the wheel surface to, for example, refresh a worn groove geometry. Furthermore, the proposed system can be mounted on either a non-CNC or a CNC conventional grinding machine and can groove and re-groove the grinding wheel without the need to remove it from the grinding wheel spindle. The novel wheel grooving system was experimentally validated by creating helically shaped circumferential grooves on the grinding wheel surface. The resulting maximum differences in groove width and depth were found to be 0.015 and 0.013 mm, respectively, for ten consecutively cut grooves. These small discrepancies are believed to be primarily due to the brittle fracture mechanism of the abrasive grits. Furthermore, the new wheel grooving system was shown to be able to create a wide range of different groove patterns on the wheel surface. A wear study was then carried out to compare the performance of both grooved and non-grooved grinding wheels. For the conditions used in this research, the results of this wear study showed that a grooved wheel not only exhibits less wear than a non-grooved wheel but also can remove approximately twice as much workpiece material before failure occurs. 相似文献
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E. Teimoury M. Modarres A. Kazeruni Monfared M. Fathi 《The International Journal of Advanced Manufacturing Technology》2011,52(1-4):235-244
In this paper, a method to determine the optimal tool orientation to make a more perfect impeller blade surface using a five-axis flank milling machine is presented. Verification of surface geometric accuracy using a 3D coordinate measuring machine is also shown. A mathematical formula is derived which includes the parameters of tool and curved surface to calculate the appropriate tool orientation, whose direction is named the optimal tool orientation. The 3D CAD software Unigraphics (UG) is used to plot models which include the curved surface and the tools of optimal tool orientation and other orientations. The reasonable overlap between curved surface and tool is obtained (overcutting) by checking the interference from the UG, its tool orientation is the optimal tool orientation. According to the optimal tool orientation and position at all cutting points on curved surface, a cutting location source file is derived, which can transform into the NC code for the five-axis tool machine to make the centrifugal impellers of various types. These impellers are measured by using the 3D Coordinate Measuring Machine to verify blade to be free of flaws, and with accurate geometry and the tool, marks are removed from its surfaces. 相似文献
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In this paper, an efficient method tor generating 5-axis cutting data for a turbine blade is presented. The interference elimination
of 5-axis cutting currently is very complicated, and it takes up a lot of time. The proposed method can generate an interference-free
tool path, within an allowance range. Generating the cutting data just point to the cutting process and using it to obtain
NC data by calculating the feed rate, allows us to maintain the proper feed rate of the 5-axis machine. This paper includes
the algorithms for: (1) CL data generation by detecting an interference-free heel angle, (2) finding the optimal tool path
interval considering the cusp-height, (3) finding the adaptive feed rate values for each cutter path, and (4) the inverse
kinematics depending on the structure of the 5-axis machine, for generating the NC data. 相似文献
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Chun Hong Park Chang Kyu Song Jooho Hwang Byung-Sub Kim 《International Journal of Precision Engineering and Manufacturing》2009,10(4):85-91
The goal of this research is to develop a multi-functional ultra precision machine to generate micro features on large surfaces.
Design and characteristic analyses of our machine are presented. The analyses include its structural analysis and accuracy
tests. Each axis of the developed machine was corrected and/or compensated from accuracy tests enough to generate grooves
on workpieces with a less than 10 μm pitch size. After compensation, the 2-dimension position error between X-axis and Y-axis
was reduced to 1.4 μm for a 400×400 mm2 surface. From a 24 hours relative thermal displacement test between Y-axis and Z-axis, the machine showed a stable thermal
displacement which was measured to be less than 1 μm. From groove machining tests, our machine could successfully generate
5 μm and 10 μm pitch grooves and showed a stable micro machining characteristics. From this research, we can conclude that
the developed machine has mechanical characteristics enough to generate less than 10 μm pitch grooves on a 400×400 mm2 surface. 相似文献
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对采用鼓形砂轮周磨自由曲面的刀位计算进行了研究。为了提高加工效率,提出了一种基于避免加工中砂轮和工件曲面局部干涉的鼓形砂轮几何参数的优化方法。在刀位计算中,砂轮被限定在摆刀平面中旋转;离散鼓形砂轮表面,计算采样点到工件曲面的有向距离,获得当前刀位的加工误差分布和加工带宽;以砂轮轴和工件曲面最小法曲率方向的夹角为优化变量,以当前刀位的加工带宽的最大化为优化目标,用格点法进行了鼓形砂轮周磨自由曲面的刀位优化。利用UG二次开发技术编程,生成了Bezier曲面的加工轨迹的计算实例,验证了所提出的砂轮几何参数和刀位的优化算法。 相似文献