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快速成形数据处理的分层算法 总被引:1,自引:0,他引:1
针对快速成形制件的精度和效率问题,分析了分层方法与层面轮廓精度等影响因素.利用快速成形制造系统普遍采用的STL初始文件,提出利用延拓逼近重构处理层面轮廓和逐步细化分层的数据处理算法,得到了精确的层面轮廓,有效地减小了台阶效应误差并提高了分层效率,与目前采用的直接分层和自适应分层等算法相比,本算法具有更高的成形精度和效率.通过仿真和实际加工验证了所提方法的有效性、实用性和系统适应性. 相似文献
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为克服STL网格化文件存在容易丢失精度等固有缺陷,提出基于STL的精确自适应分层系列算法,从提高分层截面的轮廓曲线精度出发,同时考虑到后续数控插补的适应性,采用曲率连续的适应性强的Clothoid曲线拟合算法,重构曲线轮廓并得到拟合加工点;同时在自适应分层中采用垂直轮廓参考曲线上点的切线角决定切片的厚度,有效提高了切片精度和效率,最后采用熔融沉积成形系统进行快速成形验证。结果表明,该方法有效减小了原有的STL格式文件的固有误差,提高了快速成形制件的加工表面质量和效率。 相似文献
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《机械工程与自动化》2017,(6)
目前快速成型制件的成形精度制约着该技术的推广和发展,对于给定的设备,设置不同的工艺参数将会对最终模型的成形性能、制件精度和质量等构成较大差异。分析了FDM快速成型技术的成型原理和特点,研究了分层厚度和成形角度对阶梯效应的影响。 相似文献
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快速成形的成形精度和速度往往是一对矛盾体 ,自适应分层方法是解决这一矛盾很好的方法之一。本文通过分析和比较切片轮廓信息 ,提出了一种简单而实用的适用于STL及PIC文件格式的自适应分层方法 ,并介绍了该自适应分层的算法。该方法在保证制件成形精度的前提下能极大地提高制件的成形速度 相似文献
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结合分层制造和数控加工的技术优势,提出了一种以六轴并联机床为切削加工平台、基于加工特征的复合快速成形方法。利用Parasolid modeling kernel开发了具有加工特征提取与消除、分层处理等功能的数据处理软件系统。以顶针座零件为对象进行了原型制作实验,整个制作过程需要8h,制作精度为0.05mm,与SLA方法相比具有较高的成形效率和精度。 相似文献
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先进激光制造技术研究新进展 总被引:10,自引:0,他引:10
介绍了激光板与管无模成形、激光表面强化处理、激光微细加工和激光直接沉积成形等四种激光制造前沿研究技术。阐述了基本作用原理、影响建模分析的因素和测试验证的方法。指出了各自的关键技术及研究焦点。介绍了国内外的相关研究进展。指出了在小批量多品种难加工材料成形与快速承载构件成形、复杂形面构件表面强化处理和微细构件高效加工方面的潜在用途。 相似文献
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针对在新产品的开发过程中,由于快速成型设备工作台成型尺寸的限制,对于类似摩托车覆盖件等大型快速成型样件的加工难题.本文分析了快速成型技术和精密雕刻技术在加工过程中的优缺点,提出在摩托车覆盖件的开发过程中,用精雕机和快速成型机结合的方法来进行新产品样件的制作,并且运用基于特征的数据分块技术,对大型样件进行合理的分块,再分... 相似文献
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逆向工程曲面构建与快速成型 总被引:1,自引:1,他引:0
逆向工程与快速成型技术相结合,能快速实现模型的复制,改变了传统的产品开发设计和制造模式。快速成型要求曲面必须保证一定的制作精度和光顺性,本文基于Imageware软件,结合具体的案例,就曲面构建方法和曲面的拼接质量影响因素进行了探讨,提出了较为完整的曲面逆向构建及快速成型的技术途径。 相似文献
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J. Y. Kim K. Lee J. C. Park Dr Y. H. Jung 《The International Journal of Advanced Manufacturing Technology》1998,14(12):882-888
Prototypes of a design are always needed for the purposes of visualisation and evaluation for manufacturability, functionality, and aesthetic appearance. Since the prototyping process requires a significant amount of cost and time, various rapid prototyping processes have recently been introduced. However, it is usually necessary for a part built up by a rapid prototyping system to be finished by a post-processing process, in which the stair steps on the surfaces, the support structures (if they exist), and the unprocessed material are eliminated. This post-processing is usually done manually and is a time-consuming task. Eliminating the trapped volumes (the volume of the unprocessed material entrapped by the solidified portion) is sometimes impossible in some processes.This study provides a designer with a tool to detect the existence of trapped volumes and to calculate the quantity in a given build-up direction, so that a suitable build-up direction is chosen or the part is built in pieces to avoid the problems caused by the trapped volumes. Since the proposed algorithm can efficiently calculate the amount of the trapped volumes in any build-up direction, it has the potential for such applications as optimising the build-up direction to minimise the trapped volumes. 相似文献
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快速制模是快速成型的主要应用之一,但成型件的精度难以达到快速制模对原型或型芯尺寸精度和表面精度的要求.系统分析了熔融堆积成型( FDM)工艺成型精度的影响因素,分析产生误差的根源及作用机理.针对FDM产生的误差,通过定性和定量分析,提出减小误差的途径和方法,并通过实例验证了解决翘曲变形和尺寸精度问题的方法,提高了原型的精度,对熔融堆积成型工艺精度的提高具有实际的参考价值. 相似文献
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讨论和分析了SLS快速成形伺服系统的闭环和半闭环控制,并提出了利用双闭环控制实现伺服系统的高精度控制。研究表明,SLS快速成形的双闭环控制能够获得较好的控制稳定性并能进一步提高原型件的成形精度。 相似文献
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Y. Tang H.T. Loh J.Y.H. Fuh Y.S. Wong S.H. Lee 《The International Journal of Advanced Manufacturing Technology》2005,25(9-10):895-901
A CAD application tool kit interfacing with a Unigraphics (UG) system was developed for disintegrating large and complex rapid prototyping objects into smaller and simpler components which can be fabricated by a rapid prototyping system. As the core of the tool kit, the algorithm of such disintegration is described in detail in this paper. The algorithm combines the flat planar parting method and feature-based volume decomposition. Due consideration is also given to the optimisation of the surface accuracy, the build time, and the strength and number of segments generated. Based on the algorithm and the CAD application tool kit, the disintegration of two RP objects was realised in a selective laser sintering system. 相似文献
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Hsiao-Chuan Yen Hwa-Hsing Tang 《The International Journal of Advanced Manufacturing Technology》2008,36(3-4):280-287
“Step effect” is one of the major concerns for engineers because it affects the surface quality in layer manufacturing. Instead
of constant thickness, adaptive slicing procedures use slices of variable thickness that are governed by the model geometry,
manufacturing process, material, and rapid prototyping system. The RP system has the capability of fabricating the layer between
a minimum and maximum thickness with certain intermediate thickness during the model making and is indispensable. Due to agglomeration
of powder and upward deformation of the layer, the layer’s thickness in powder-based rapid prototyping processes is restricted.
To improve surface quality, the current study constructs a paving system to minimize the layer thickness. Based on a wet process-ceramic
laser rapid prototyping technique, a paving system, which can fabricate ultra-thin layers to a thickness of 20 μm and can
achieve instant layer drying, was successfully constructed. A strategy of compensative layer was induced to improve accuracy
of the Z-axis. Due to the ultra-thin layers, a plane surface finishing of Rz = 15∼24 μm was obtained. 相似文献