曲面造型研究与程序开发

为了满足叶轮叶片类具有复杂曲面形状的零件的数控加工需求,文中以非均匀B样条为数学模型,应用Delphi 5.0程序开发工具进行程序开发,分析了曲面造型的误差,并画出了直观的误差图,最后,将这一理论应用到叶轮叶片曲面造型之中.     

基于UG透平叶轮数字化建模的研究

介绍了复杂自由曲面零件——透平叶轮数字化建模的思路。分析了叶轮建模的具体要求和步骤,研究了基于典型CAD/CAM软件UG的整体叶轮实体造型方法,详细论述了从叶片数据的获得、处理,叶片边缘线及截面轮廓的生成和修改及拟合成光滑的叶片实体等过程,指出叶轮造型的具体思路、重点、难点问题及解决方法,在此基础上加工出的叶轮已应用在透平膨胀机的自主研发中。     

基于Solidworks轴流泵叶轮叶片的三维建模方法

轴流泵叶轮叶片是一种特殊的曲面零件，这种零件的几何造型是三维建模中的重点和难点。基于Solidworks的三维建模功能，研究了轴流泵叶轮叶片的三维建模方法，并以具体实例实现了轴流泵叶轮叶片的三维模型。     

基于Cimatron叶片多轴数控加工

为提高叶片数控加工效率和质量,提出了一种简便的、快捷的、优化的设计方法。以叶片高效率、高质量多轴数控加工为目标,结合企业生产实际,采用Cimatron叶轮加工专用模块进行设计,采用优化的数控加工工艺对零件进行多轴数控加工编程,为叶轮的数控加工提供了设计思路和方法,对其他类零件的数控加工方案具有重要的指导意义。     

基于NURBS理论的叶轮五坐标CAD／CAM技术研究

本文采用当今国际流行的NURBS理论，对叶片及叶轮等五坐标零件进行曲线拟合，曲面造型，曲线及曲面求变，加工刀具迹求解等技术难题的研究，并开发了后置处置，加工轨迹仿真等模块。以DNC方式控制CNC机床进行零件加工，为建立叶片，叶轮等五坐标零件的CAD／CAM集成系统奠定了基础。     

整体式叶轮曲面造型的分型及分向光顺方法

整体式叶轮是发动机的关键部件,叶片的三维造型又是叶轮设计的难点,同时也是影响发动机叶轮性能的重要因素。针对五轴数控加工中心加工整体式叶轮时叶片表面质量较差的问题,总结出了一套基于UG软件的曲线、曲面分型及分向光顺方法,使曲面造型的光顺效果得到显著地改善,从而提高了实际加工时整体式叶轮叶片的表面质量。实例表明,此方法便捷、有效,可明显改善叶片表面质量,满足工程实际的使用要求。为整体式叶轮叶片复杂曲面的模型建立提供了思路和方法。     

基于UG的叶轮实体造型和数控编程技术研究

介绍了叶轮类零件产品设计与制造工艺,提出了叶轮产品造型中的曲线模型原则,对5坐标加工中的机床结构、刀轴控制、加工工艺、加工参数进行了详细的分析,并运用在实际加工中,为复杂产品的模型建立和多坐标数控编程提供了设计思路和方法.     

导向叶片的数控加工技术探讨

根据导向叶片叶型的造型,分析了影响叶片加工精度的各种因素,包括机床、夹具、零件等,分析了如何进行该叶片叶型的加工并最终得出零件的加工方法。     

空间曲面叶片的数控加工

叶轮是汽轮机、水轮机、压汽机、推进器等装置的关键部件.叶片的型面的质量则直接影响叶轮的工作效果,进而直接影响整机的工作性能.空间曲面叶片的加工是叶轮制造工业中的难点.通过对轴流式压缩机叶轮叶片的造型及数控编程,在五轴数控加工中心上使轮毂与叶片在一个毛坯上一次加工完成,它可以满足转子产品强度要求,曲面误差小,动平衡时去质量较少,因此是较理想的加工方法.     

雕塑曲面体混流式叶片的多轴联动数控加工编程技术

转轮叶片是水轮机能量转换的关键部件,也是最难加工的零件,目前多轴联动数控加工是解决该类大型雕塑曲面零件最有效的加工方法。多轴联动数控加工编程则是实现其高精度和高效率加工的最重要环节。本文介绍混流式水轮机叶片五轴联动数控加工大型雕塑曲面编程中涉及到转轮叶片三维造型、刀位轨迹计算、切削仿真、机床运动碰撞仿真、后置变换等关键技术。通过对这些技术的链接和研究,开发实现了大型叶片的多轴联动加工。     

压气机叶轮五轴联动数控加工技术探析

为了能够更好地实现压气机叶轮加工,应设计出符合加工要求的产品,使实际加工中的叶型与理论上的叶型能够达到高度的吻合.为实现高效、高精度和高强度,对压力机叶轮五轴联动数控加工的关键工艺进行了深入的研究分析,其中包括压力机叶轮叶片的几何造型、刀具加工运行的轨迹优化等多个方面,为高精度、高效的压力机叶轮五轴联动数控加工提供给了有效的方法.     

Optimal strategy for finishing impeller blades using 5-axis machining

This paper deals with the machining of impeller blades by defining a numerical method to optimize the finishing strategy. This method is based on the evaluation of new multi-physical functional indicators, which express the geometric and economical performances of a toolpath. Geometric indicators are defined to ensure functional requirements: aerodynamic, mechanical, and machining-related. Using these indicators, the viable impeller blade finishing strategies are compared, considering their geometric performances and production cost. The production cost is represented by machining time, which is accurately computed to limit blade and tool deflections, in order to reduce and control the geometric errors caused by these deflections. Machining time is directly linked to the feed rate, which is coupled to radial cutting forces. Thus, the finishing strategy is optimized by considering simultaneously a complete set of impeller machining problems: geometric errors and deflections. The method presented to optimize the blade finishing strategy is then applied to an industrial impeller used in a pump.     

带冠整体叶轮加工现状及新方法探索

综述了带冠整体叶轮的特点及国内外研制工作的现状，针对现有工艺方法的不足，提出了一种新的加工方法，即电解加工与电火花加工的组合电加工方法，进而对该工艺方法进行了介绍，分析了其技术特点。通过试验，其可行性得到了验证，有望成为带冠整体叶轮叶片型面的一种有效加工方法。     

An efficient five-axis machining method of centrifugal impeller based on regional milling

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.     

螺旋桨叶型数控加工编程研究

文章提出一种螺旋桨叶型数控加工编程新方法,通过实际加工证明其实用可靠,而且大大提高了表面加工质量和加工效率.     

叶轮造型与加工支撑软件的选择及技术特性

三元整体叶轮叶片形状复杂,制造需采用CAD/CAM技术,以三维造型与编程软件编程,应用五坐标数控机床加工实现。对国内常用的典型三维CAD/CAM软件的建模特点和CAM性能进行了分析与比较。按照叶轮造型与加工对支撑软件的技术要求,指出适合于叶轮造型的CAD系统软件应以Pro/E和UG两种软件为主。在CAM方面,通用型CAM系统,可选用PowerMILL软件。如果条件允许,可选择专用叶轮加工软件NRECMAX-PAC或带叶轮模块的HyperMILL软件。几种软件混合使用,充分利用不同软件各自的优势,在实际应用中会取得很好的效果。     

<Emphasis Type="Bold">An Integrated Machining Approach for a Centrifugal Impeller</Emphasis>

When a 3-axis CNC machining centre is used for producing an impeller, great difficulties, i.e. collisions between the cutting tool and the impeller, can occur. The blade of an impeller is usually designed with a ruled surface. As the surface is normally twisted in design to achieve the required performance, it can cause overcut and collision problems during machining. The hub of the impeller is usually designed with an irregular surface, and is machined within a narrow and deep groove. The issues – how to satisfy the quality requirements of the part, reduce the machining time, and avoid the occurrence of collision – become an integral problem. This work develops an integrated 5-axis machining module for a centrifugal impeller by combining related machining technologies. As a result, cutter location (CL) data based on the geometric model of blade and hub are generated. Finally, the CL data are confirmed through software simulation. The results of verification show that the machining methodology and procedure adopted are successful.     

Optimization of the rough cutting factors of impeller with five-axis machine using response surface methodology

Turbo-machinery gradually has expanded its business into the automotive and aircraft industries. A core part of turbo-machinery is the impeller which can lead to manufacturing problems because it has twisted surfaces. Therefore, impeller machining requires five-axis machining technology and expert knowledge. Five-axis machining has the advantages of being able to select a variety of tool axis in the machining and remove uncut region which are impossible in the three-axis machining, which could obtain high productivity and good surface quality. Rough cutting is one very important operation as it affects productivity in the impeller machining and it is necessary to determine cutting strategies and select optimal cutting condition. This paper proposes a statistical method to optimize the rough cutting parameters in impeller machining by response surface methodology and efficient strategy to divide cutting region. Firstly, the rough operation was divided into three steps to remove volume from inducer to exducer and two steps were also added to remove the fillets between blade surfaces and hub surfaces. These machining strategies are selected as the qualitative factors when the response surface method is used. Secondly, cutting time was set as the response factor for productivity, and step-down, step over, and feed rate were determined as independent factors. Finally, the response surface model was estimated by a single surface in order to predict rough cutting time and the optimum cutting conditions were searched by the estimated model.     

整体叶轮五轴数控插铣加工刀位轨迹生成算法研究

为了提高整体叶轮粗加工效率和质量,提出了一种整体叶轮五轴插铣加工刀位轨迹的计算方法。根据整体叶轮的几何特征和插铣特点,定义与叶轮轴线垂直的截平面族,构造截平面与叶片型面交线的单侧包络直线族,作为边界面加工刀位,在边界面刀位之间插值,得到整个流道的插铣加工刀位轨迹。运用UG/Open API开发了整体叶轮插铣加工软件模块,最后通过实例验证了所提出的方法是有效的。