共查询到19条相似文献,搜索用时 109 毫秒
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自由曲面3轴NC加工的全干涉检查研究 总被引:1,自引:0,他引:1
对自由曲面用球头刀进行3轴NC加工的干涉检查方法进行了研究,提出了一种新的干涉检查方法,该方法不仅可检查曲面加工时的局部干涉,而且还可对曲面加工时的全局干涉进行检查。通过与传统干涉检查方法的比较,并对不同刀具半径下干涉结果的比较,验证了本文提出的干涉检查方法的完整性、精确性和实时性,可指导曲面加工时刀具的选择。最后的实例证实了该方法及算法是合理可行的。 相似文献
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为了提高三角网格曲面五轴加工的加工效率,提出了基于最大材料去除率(maximal materialremoval rate,MMR)的平底刀五轴加工刀轨生成算法。首先计算无曲率干涉且具有最大材料去除率的网格曲面五轴加工的刀具方位角;然后在确定网格曲面可能干涉区域的基础上,提出刀触点处干涉性假设,并以最大材料去除率、刀具无曲率干涉和全局干涉为约束条件,采用二分法确定具有最大材料去除率的无干涉刀具方位角;最后采用截面线法生成三角网格曲面MMR平底刀五轴加工刀轨。通过实验验证了采用文中算法生成的刀轨进行加工能够获得较高的加工效率和表面质量。 相似文献
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用投影方法进行数控加工干涉检查与修正 总被引:7,自引:1,他引:7
解决了数控加工的干涉检查问题。数控加工的干涉检查实际上就是检查刀具曲面和被加工曲面的有向距离。根据有向距离的符号进行干涉与否的判断并由其值(极值)的大小及极值的位一进行干涉修正,利用刀具曲面是一个绕刀轴的旋转面,易抉辅度离散处理的特点,不离散(分割)待检查曲面,而离散刀具曲面,在经度方向上可用刀具轮廓线(母线)绕刀轴旋转得到的一组均通过刀尖点的曲线来逼近,在纬度方向上可用圆心在刀轴上的一组经过同一条毋线的圆来逼近。利用相邻点间的相关性,采用跟踪技术求取离散的刀具曲面嵌入被检查曲面的干涉深度及其位置。 相似文献
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对自由曲面用带角圆柱铣刀3轴NC加工提出了系统的刀具干涉检测方法。加工自由曲面时,刀具干涉可以出现在包括刀具驱动面的刀具周围的任何地方。本文提出先检测自由曲面上可能产生刀具干涉的区域,然后再生成刀具路径,这样不但可极大地简化安排刀具路径的过程,改善加工的精度和可靠性,而且有利于产品的几何设计和影响加工效率的刀具选择。研究表明所提方法和算法是合理有效的。 相似文献
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基于坐标系变换原理进行五轴数控加工刀具全局干涉检测,将曲面检测点变换到刀具局部坐标系中,通过判断曲面点是否落到刀具半径范围内来判断是否为干涉点,大大降低了计算量,提高了数控加工效率.对干涉点通过最小二乘法确立最小包容区域以及刀具姿态最优偏转轴及偏转角.为了防止在偏转过程中产生新的干涉,确立了刀具姿态有效区域,使得偏转角度能够避免刀具干涉且在有效区域内.通过实例验证了所提方法的可行性和有效性. 相似文献
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刀具的类型与尺寸是影响曲面加工效率的一个重要方面。刀具尺寸过小将导致零件程序膨胀、编程效率下降及曲面加工效率的降低。而刀具尺寸过大则在曲面的若干区域将无法实现刀具的无干涉切削,干涉的避免只能通过抬刀处理来实现,增加了后续处理的工作量,从而降低了曲面的加工效率。因此,刀具类型与尺寸的合理选择是提高曲面加工效率的重要手段。 相似文献
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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
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通过深入研究提出了一种直线段相对于圆形窗口位置关系的快速判别方法 ,以此方法可以大大提高分析逼近曲面的三角片与刀具在刀轴方向的投影之间关系的效率 ,从而加快了自由曲面三轴数控加工的干涉检验速度 相似文献
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YI Xianzhong MA Weiguo QIHaiying YAN Zesheng GAO Deli 《机械工程学报(英文版)》2008,21(3):52-57
A new milling methodology with the equivalent normal curvature milling model machining freeform surfaces is proposed based on the normal curvature theorems on differential geometry. Moreover, a specialized whirlwind milling tool and a 5-axis CNC horizontal milling machine are introduced. This new milling model can efficiently enlarge the material removal volume at the tip of the whirlwind milling tool and improve the producing capacity. The machining strategy of this model is to regulate the orientation of the whirlwind milling tool relatively to the principal directions of the workpiece surface at the point of contact, so as to create a full match with collision avoidance between the workpiece surface and the symmetric rotational surface of the milling tool. The practical results show that this new milling model is an effective method in machining complex three- dimensional surfaces. This model has a good improvement on finishing machining time and scallop height in machining the freeform surfaces over other milling processes. Some actual examples for manufacturing the freeform surfaces with this new model are given. 相似文献
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回顾了超精密加工技术的发展,主要包括超精密加工设备的开发历程,以及超精密单点金刚石切削技术基础,并对微工程技术作一简要介绍;重点论述微结构自由曲面的微纳切削技术,包括单点金刚石车削(Single point diamond turning, SPDT),快刀伺服加工(Fast tool servo, FTS),金刚石微凿切(Diamond micro chiseling, DMC),光栅铣削等技术。指出微结构自由曲面测量领域面临的挑战和存在的问题,包括接触式测量和非接触式测量。通过几个典型微结构自由曲面的加工及测量的应用进行举例说明;最后介绍我国在超精密加工机床领域内的研制情况,展望了超精密切削技术未来发展趋势。 相似文献
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Hongbin Liang Xia Li 《The International Journal of Advanced Manufacturing Technology》2013,68(9-12):2791-2800
Five-axis machining is more widely used in manufacturing of freeform surfaces. However, in five-axis machining of freeform surfaces, incomplete information exchange between computer numerical control (CNC) and computer-aided design/computer-aided manufacturing (CAM) results in many limitations need to be rectified. In the paper, a new structure of CNC based on STEP-NC standard is proposed, where tool path planning, tool offset, and inverse kinematics are transferred from CAM to CNC. In order to guarantee good openness, open platform and standard interface are applied in the development. Technology of module collaboration and design of data flow are studied. A five-axis real-time interpolator for non-uniform rational B-spline surfaces machining is realized. Based on these technologies, a five-axis CNC is developed in the manner of software realization, which consists of interpreter, task coordinator, axis group, softPLC, etc. The software CNC system has been applied on a tilt-rotary type five-axis machine tool, where the milling experiment has been performed successfully. 相似文献
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《机械工程学报(英文版)》1999,(2)
0INTRODUCTIONFreeformsurfacemachiningisanimportantfeatureinmanyengineringparts.Inordertoobtaindesiredsurfacequalityandhighpro... 相似文献
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Characteristics of Inclined Planes According to the Variations of Cutting Direction in High-Speed Ball-End Milling 总被引:2,自引:2,他引:0
M. C. Kang K.K. Kim D.W. Lee J. S. Kim N. K. Kim 《The International Journal of Advanced Manufacturing Technology》2001,17(5):323-329
The recent developments of the manufacturing industry require the machining of freeform surfaces using a ball-end mill. The
ball-end mill is geometrically complex. For this reason, there are frequent changes of the contact point between a workpiece
and a tool, which changes the machining characteristics when machining a freeform surface. In this study, a comparative evaluation
of cutting characteristics will be made for a workpiece with inclined planes at angles of 15°,30°, and 45° each using four
possible tool paths in down cutting. Then, tool life will be evaluated for heat-treatment materials of high hardness before
obtaining the optimal tool path, which makes machining stable and improves tool life. 相似文献