共查询到20条相似文献,搜索用时 15 毫秒
1.
Inhaeng Cho Dr Kunwoo Lee Jongwon Kim 《The International Journal of Advanced Manufacturing Technology》1997,13(8):523-529
In five-axis milling, optimal cutter location data (CL-data) should be generated to have advantages over three-axis milling in terms of accuracy and efficiency. This paper presents an algorithm for generating collision-free CL-data for five-axis milling using the potential energy method. By virtually charging the cutter and part surfaces with static electricity, global collision as well as local interference is eliminated. Moreover, machining efficiency is simultaneously improved by minimising the curvature difference between the part surface and tool swept surface at a cutter contact point (CC-point). 相似文献
2.
整体叶轮五轴侧铣数控加工方法的研究 总被引:7,自引:0,他引:7
为提高整体叶轮的五轴编程和加工的能力,生成合理的刀位文件,在制定出合理的加工工艺的基础上,提出了一种适合于直纹面叶片五轴侧铣加工的刀轴矢量计算方法.对两个相邻叶片的直母线进行插值后,得到的刀轴矢量能完全避免刀具与叶片之间的干涉问题.同时,提出了一种小四边形参数模型来解决直线与自由曲面求交问题,并成功应用于刀心计算中.实例计算表明,所提出的方法能很好地应用于整体叶轮的五轴加工. 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
4.
自由曲面的五坐标端铣加工研究 总被引:2,自引:1,他引:2
针对自由曲面的五坐标端铣加工,建立了平底刀有效切削轮廓的数学模型,分析了刀具姿态对有效切削轮廓及加工效率的影响。沿行距方向,通过对被加工曲面法截线的偏置曲线与有效切削轮廓求交,得到一种走刀行距的计算方法。探讨了影响走刀行距的因素,在不发生干涉的前提下,小的后跟角和侧偏角有利于加工行距的提高。结合平底刀加工不发生过切的充要条件和被加工曲面沿行距方向的法曲率,给出了后跟角的自动计算方法。算例表明,所提出的走刀行距及刀具倾角的计算方法合理可行,能够有效提高计算精度和加工效率。 相似文献
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汽车玻璃钢化风栅成形器五轴加工刀轴矢量插值 总被引:4,自引:0,他引:4
为了解决汽车玻璃钢化风栅成形器五轴加工时刀轴矢量频繁变换造成冲击或发生干涉等问题,提出一种刀轴矢量插值方法。根据被加工曲面的几何形状和误差要求确定刀触点,根据被加工曲面的微分几何性质确定刀轴矢量的后跟角和摆转角。在已确定刀触点处的刀轴矢量的基础上,采用空间矢量光滑插值方法获得一系列中间位置刀轴矢量使刀轴变化较均匀。以货车前挡风玻璃钢化风栅成形器的一个拼镶块工作表面和风栅孔五轴NC加工为例进行仿真。结果表明,该刀轴矢量光顺方法可以避免刀轴方向频繁变换,同时也可有效地提高加工精度。 相似文献
7.
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
8.
Effects of inclination angles on geometrical features of machined surface in five-axis milling 总被引:1,自引:1,他引:0
Xiaoxiao Chen Jun Zhao Yongwang Dong Shiguo Han Anhai Li Dong Wang 《The International Journal of Advanced Manufacturing Technology》2013,65(9-12):1721-1733
With the development of manufacturing technology, five-axis milling has been one of the most important solution strategies in machining field. To deepen the understanding of multi-axis processing and improve the application level of the technology, the current work was carried out. This paper investigated the effects of tilt and lead angle on the scallop height, surface roughness, surface topography, and surface damages in five-axis ball-end milling process. Both geometrical analysis and experiment research are conducted to investigate the scallop height after five-axis milling, and variation of the surface roughness and surface topography with tool inclination angle obtained from the experiments was analyzed. Surface damages under the different inclination angles were also observed and analyzed with optical profiler. Several conclusions are made as follows. The inclination angles of the ball-end mill have no effect on the scallop height when only the spherical part of the cutter participates in the cutting process according to the geometrical analysis. Surface roughness with regard to tilt angles presents symmetrical characteristic around 0°. Surface texture feature, especially the texture direction, is closely related with the tool posture. The surface concave pits, convex marks, microscopic cracks, and spot corrosions are mainly the damage forms of the machined surface. More surface blemishes appeared when small inclination angles are adopted in cutting. As a result, the recommendatory inclination angle values for inclination angle are proposed. A better understanding of the five-axis machining process would be given by the detailed analysis of generation reason of the machined surface features, and the results could provide support for process parameter optimization. 相似文献
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Xiao-zhong Deng Geng-geng Li Bing-yang Wei Jing Deng 《The International Journal of Advanced Manufacturing Technology》2014,71(5-8):1049-1057
In order to solve some common problems of CNC-machined spiral bevel gears such as small cutting strip width and poor surface quality, while milled by the ball-end, a machining method of face milling using a disk cutter with a concave end is presented. The research theories are based on the foundation of spiral bevel gears’ geometry structure. Firstly, a bigger diameter disk cutter with a concave end is selected. Then, change the setting order of cutter orientation angles. The functions of cutter tilt and yaw angle are separated, and tooth surfaces machined with big cutting strip width and no bottom land gouge can be expected. Since the cutter yaw angle, determined firstly by cutting contact point, positions in the tooth surface machine, the bottom land gouge interference can be avoided effectively. Then, the tilt angles of the gear pair, both side tooth surfaces, are determined by the theory of sculptured surfaces machined by the flat-end cutter, respectively. As a result, the improved cutting strip width and machining efficiency can be realized. Finally, feasibility of this method is verified through machining experiment and measurement of a spiral bevel gear pair. 相似文献
11.
Generating tool-path with smooth posture change for five-axis sculptured surface machining based on cutter’s accessibility map 总被引:4,自引:4,他引:0
L. L. Li Y. F. Zhang H. Y. Li L. Geng 《The International Journal of Advanced Manufacturing Technology》2011,53(5-8):699-709
In five-axis high speed milling, one of the key requirements to ensure the quality of the machined surface is that the tool-path must be smooth, i.e., the cutter posture change from one cutter contact point to the next needs to be minimized. This paper presents a new method for generating five-axis tool-paths with smooth tool motion and high efficiency based on the accessibility map (A-map) of the cutter at a point on the part surface. The cutter’s A-map at a point refers to its posture range in terms of the two rotational angles, within which the cutter does not have any interference with the part and the surrounding objects. By using the A-map at a point, the posture change rates along the possible cutting directions (called the smoothness map or S-map) at the point are estimated. Based on the A-maps and S-maps of all the sampled points of the part surface, the initial tool-path with the smoothest posture change is generated first. Subsequently, the adjacent tool-paths are generated one at a time by considering both path smoothness and machining efficiency. Compared with traditional tool-path generation methods, e.g., iso-planar, the proposed method can generate tool-paths with smaller posture change rate and yet shorter overall path length. The developed techniques can be used to automate five-axis tool-path generation, in particular for high speed machining (finish cut). 相似文献
12.
Tao Chen Peiqing Ye Jinsong Wang 《The International Journal of Advanced Manufacturing Technology》2005,25(3-4):343-349
The tool interference problem is the most critical problem faced in sculptured surface machining. This paper presents a methodology for interference detection and avoidance in five-axis NC machining of sculptured surfaces with a filleted-end cutter. The surfaces to be machined are divided into convex and non-convex regions. There is no local interference inside the convex regions. For the non-convex regions, based on the analysis of the different local interference, local gouging is first detected and avoided by determining optimal cutter orientations. Rear gouging detection and avoidance algorithms are then proposed for simple smooth surfaces and complex shaped surfaces, respectively. The techniques presented in this paper can be used to generate interference-free tool paths. The realistic results indicate that the proposed method is feasible and reliable . 相似文献
13.
This paper presents an efficient five-axis machining method of centrifugal impeller based on regional milling. As the base of the machining method, geometry of the centrifugal impeller and blade surface is analyzed, and sub-machining regions are presented through the division of the double three-cubic d non-uniform rational B-spline (NURBS) surface. In rough milling, the cutter parameters, tool path interval, tool path curves, and the fixed tool axis vector are calculated by the novel algorithm based on regional milling; the biggest cutter and smaller tool path length are obtained. In finish milling, for the aerodynamic performance of the finished impeller, the tool path curves are modified and interlinked to make them uniform and orderly. A modified algorithm of the finish milling of the blade surface is proposed, and not only are the machining errors reduced; their reasonable distribution is also realized. Numerical simulation and a real test impeller are presented as the test of the proposed method. 相似文献
14.
《Computer Integrated Manufacturing Systems》1998,11(4):337-350
This paper discusses automatic tool path generation for five-axis filleted end mill finish-surface machining. A new method of automatic five-axis tool path generation is introduced called Grind-Free (GF) tool path generation. GF surfaces result from tool paths that avoid gouging and have scallops that are within the surface profile or waviness tolerances. New algorithms are presented for determining tool forward step and tool path step-over that produce a GF surface. Gouge-free tool paths can be generated directly from CAD data based solely on local and global machining constraints. The proposed methodology for GF tool path generation has been implemented in the C language using the CODE/Robline system. Surfaces were machined on a Boston Digital 505 five-axis milling machine to confirm this method. 相似文献
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针对自由曲面的五轴数控加工,提出一种新的刀具选择方法,此算法可以自动地选择出最优刀具组合,每个刀具对应一个或多个特定的加工区域。多刀具组合的加工方法既可以保证加工曲面的精确性,又可以实现大刀具的高效加工。此外,还提出了种五轴教控加工时间的近似算法,通过对比用刀具组合加工时间和单个刀具加工时间,从而证明了该方法的有效性。 相似文献
18.
余摆线铣削因切削力小、表面质量和生产率高,而广泛应用于高速加工中。球头铣刀因适应性好,且姿态可灵活调整,而成为多轴加工复杂表面的常用刀具。然而,球头铣刀齿形复杂,余摆线铣削的运动轨迹方向不断变化,工件的材料去除和表面形貌的创成过程异常复杂,传统方法建模困难。提出一种球头铣刀余摆线加工表面形貌的数值仿真方法,根据齐次坐标矩阵变换原理建立刀齿的运动轨迹方程,通过改进Z-MAP算法完成了加工表面形貌的仿真。该算法通过建立刀齿微元的随动矩形包围圈和瞬时扫掠四边形,使用角度累加法快速地获取刀齿微元在单位时间步长内扫掠到的工件网格点,根据多元函数的泰勒公式,用线性插值的方法求出该网格点的高度坐标。仿真结果表明球头铣刀余摆线铣削的表面形貌整体上优于普通直线铣削。试验结果表明,在垂直和倾斜加工条件下,球头铣刀余摆线铣削获得的表面形貌与仿真结果具有较高的一致性,说明所提出的方法可以预测球头铣刀余摆线的加工表面形貌。 相似文献
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Geometric error compensation for five-axis ball-end milling by considering machined surface textures
Guoqiang Fu Tengda Gu Hongli Gao Yu’an Jin Xiaolei Deng 《The International Journal of Advanced Manufacturing Technology》2018,99(5-8):1235-1248
Arbitrarily adjusting tool poses during error compensation may affect the quality of surface textures. This paper presents one tool center limitation-based geometric error compensation for five-axis ball-end milling to avoid the unexpected machined textures. Firstly, the mechanism of cutter location generation with cuter contact (CC) trajectory is analyzed. Due to zero bottom radius of ball-end cutter, CC points of the surface are only related to the tool center of the cutter. Realizing that, tool center limitation method of ball-end milling is established based on the generation of movements of all axes in order to ensure the machined textures. Then, geometric error compensation of ball-end milling is expressed as optimizing rotation angles of rotary axes by limiting tool centers of cutter locations. Next, particle swarm optimization (PSO) is intergraded into the geometric error compensation to obtain the compensated numerical control (NC) code. The limited region for particles of rotation angles is established, and moving criterion with a mutation operation is presented. With the help of the tool center limitation method, fitnesses of all particles are calculated with the integrated geometric error model. In this way, surface textures are considered and geometric errors of the machine tool are reduced. At last, cutting experiments on five-axis ball-end milling are carried out to testify the effectiveness of the proposed geometric error compensation. 相似文献