An allowance allocation method based on dynamic approximation via online inspection data for deformation control of structural parts

Deformation resulting from residual stress has been a significant issue in machining. As allowance allocation can directly impact the residual stress on part deformation, it is essential for deformation control. However, it is difficult to adjust allowance allocation by traditional simulation methods based on residual stress, as the residual stress cannot be accurately measured or predicted, and many unexpected factors during machining process cannot be simulated accurately. Different from traditional methods, this paper proposes an allowance allocation method based on dynamic approximation via online inspection data for deformation control of structural parts. An Autoregressive Integrated Moving Average (ARIMA) model for dynamic allowance allocation is established so as to approach the minimum deformation, which is based on the in-process deformation inspection data during the alternative machining process of upside and downside. The effectiveness of the method is verified both by simulation cases and real machining experiments of aircraft structural parts, and the results show that part deformation can be significantly reduced.     

开放式数控系统--新一代NC的主流

在分析传统数控封闭体系结构固有不足的基础上，引入了开放式数控系统的概念，并对其技术特征和开放途径进行了探讨。简要介绍了国外开放式数控的研究动态，指出了开展开放式数控研究对国产数控技术进步的重要意义     

选购加工中心诸因素的分析处理

数控加工中心的选购是企业技术改造的重要一环，本文对选购的前提条件、机床性能指标及机床价格进行了探讨分析。     

Process-scheme-driven N C machining cell for automatic construction of aircraft structural parts

In order to enhance the NC programming efficiency and quality of aircraft structural parts （ASPs）, an intelligent NC programming pattern driven by process schemes is presented. In this pattern, the NC machining cell is the minimal organizational structure in the technological process, consisting of an operation machining volume cell, and the type and parameters of the machining operation. After the machining cell construction, the final NC program can be easily obtained in a CAD/CAM system by instantiating the machining operation for each machining cell. Accordingly, how to automatically establish the machining cells is a key issue in intelligent NC program- ming. On the basis of the NC machining craft of ASP, the paper aims to make an in-depth research on this issue. Firstly, some new terms about the residual volume and the machinable volume are defined, and then, the technological process is modeled with a process scheme. Secondly, the approach to building the machining cells is introduced, in which real-time complement machining is mainly considered to avoid interference and overcutting. Thirdly, the implementing algorithm is designed and applied to the Intelligent NC Programming System of ASP. Finally, the developed algorithm is validated through two case studies.     

基于ANSYS的参数化薄壁件加工变形分析与计算

随着对航空产品性能要求的进一步提高,现代航空工业中广泛使用薄壁件零件.由于薄壁件零件刚度差,在加工过程中极易发生变形.建立了参数化薄壁件加工过程有限元模型,借助有限元软件ANSYS 10.0对薄壁件加工变形量进行分析计算研究.由于ANSYS本身功能有限,不能提供较为友好的图形化界面输入,所以基于C#环境完成了ANSYS...     

UG软件系统在某框数控加工中的应用

２４５０框是机身的主要受力构件，尺寸大，形状复杂，加工困难。本文主要介绍采用ＵＧ软件对该框进行数控编程的方法，以及编程中对几个主要技术问题的解决。     

基于CATIA生成数控加工路径的机器人纤维铺放轨迹规划

纤维铺放轨迹规划是纤维铺放成型中控制加工路径的关键步骤,直接影响复合材料构件的成型精度和铺放效率。本文基于成熟的商业化CATIA数控加工编程软件进行纤维铺放轨迹计算,获取待处理的加工路径,利用矢量补充和格式转换算法解决了铺放轨迹信息与FANUC机器人兼容性差的问题;借助插值算法求出了输送点和剪断点,补充了铺放轨迹信息,进而得到了完整的铺放信息,缩短了开发周期。在基于FANUC机器人的铺放装备上对某飞机舱门进行铺放实验,验证了基于CATIA数控加工技术的纤维铺放轨迹生成方法具有可行性,铺放轨迹结束点位置误差及轨迹间距误差都在±0.5mm之内。     

Design and implementation of five-axis transformation function in CNC system

To implement five-axis functions in CNC system, based on domestic system Lan Tian series, an improved design method for the system software structure is proposed in this paper. The numerical control kernel of CNC system is divided into the task layer and the motion layer. A five-axis transformation unit is integrated into the motion layer. After classifying five-axis machines into different types and analyzing their geometry information, the five-axis kinematic library is designed according to the abstract factory pattern. Furthermore, by taking CA spindle- tilting machine as an example, the forward and the inverse kinematic transformations are deduced. Based on the new software architecture and the five-axis kinematic library, algorithms of RTCP （rotation tool center point control） and 3D radius compensation for end-milling are designed and realized. The milling results show that, with five-axis functions based on such software struc- ture, the instructions with respect to the cutter＇s position and orientation can be directly carried out in the CNC system.     

复杂曲面五轴数控加工中刀具位置优化

针对复杂曲面五轴数控加工的刀具位置优化进行了研究并提出了一种基于五轴数控加工中非线性误差的分析和补偿的刀具位置优化方法。首先,简述了曲面加工中所用的平底圆角铣刀刀具位置的计算方法;然后,对刀具位置进行非线性误差分析并建立非线性误差模型,并基于这个模型得出插补段的最大非线性误差;接着通过对非线性误差模型中的非线性误差进行检测计算和补偿,最终得到满足加工精度要求的刀具位置。最后对该方法进行了模拟仿真。模拟的结果显示非线性误差的补偿对复杂曲面数控切削成形的几何精度有很重要的影响。     

Vibration coupling effects and machining behavior of ultrasonic vibration plate device for creep-feed grinding of Inconel 718 nickel-based superalloy

Ultrasonic vibration-assisted grinding(UVAG) is an effective and promising method for machining of hard-to-cut materials. This article proposed an ultrasonic vibration plate device enabling the longitudinal full-wave and transverse half-wave(L2T1) vibration mode for UVAG.The characteristics of two-dimensional coupled vibration in different directions were analyzed on the basis of apparent elastic method and finite element method. Furthermore, a correction factor was applied to correct the freque...