Optimal machine tool spindle drive gearbox design

Many machine tools are equipped with a motor-gearbox to extend the constant power range of the machine tool spindle drive motor at low speeds. Currently, in the latest spindle drive motor technology, the gearboxes are integrated in-line between the water-cooled motor and the spindle inside the machine tool’s ram. The functionality of a spindle gearbox depends directly upon its constructional solution, and on the kinetic energy corresponding to this solution. In this work, spindle gearboxes are optimized taking this design factor into account. In the authors’ opinion, the results could be of great interest for spindle drive gearbox manufacturers.     

六自由度并联运动机床奇异性研究

6-PSS并联运动机床的奇异性分析是6-PSS并联运动机床其它分析的基础,也是空间机构学分析的一个难点。本文首先解释了并联运动机床奇异性特征,通过建立6-PSS并联运动机床结构数学模型,实现了参数化设计。利用螺旋理论空间分析的优势,建立了6-PSS并联运动机床的Plücker坐标,方便地给出机床受力Jacobian矩阵,同时利用Matlab强大数学计算功能,精确的分析出并联机床的奇异性空间,降低了并联运动机床奇异分析的复杂性。     

刀具课程设计题库的设计与开发

论述了应用VB及ADS编程技术开发刀具课程设计题库的过程.VB技术的应用,使得软件界面友好,操作简便,而ADS编程技术又充分发挥了AutoCAD软件的绘图优势,使软件的工件图直接、简洁.该软件的开发与应用,对于教学效率的提高有积极的意义.     

Parameters optimization of a novel 5-DOF gasbag polishing machine tool

The research on the parameters optimization for gasbag polishing machine tools, mainly aims at a better kinematics performance and a design scheme. Serial structural arm is mostly employed in gasbag polishing machine tools at present, but it is disadvantaged by its complexity, big inertia, and so on. In the multi-objective parameters optimization, it is very difficult to select good parameters to achieve excellent performance of the mechanism. In this paper, a statistics parameters optimization method based on index atlases is presented for a novel 5-DOF gasbag polishing machine tool. In the position analyses, the structure and workspace for a novel 5-DOF gasbag polishing machine tool is developed, where the gasbag polishing machine tool is advantaged by its simple structure, lower inertia and bigger workspace. In the kinematics analyses, several kinematics performance evaluation indices of the machine tool are proposed and discussed, and the global kinematics performance evaluation atlases are given. In the parameters optimization process, considering the assembly technique, a design scheme of the 5-DOF gasbag polishing machine tool is given to own better kinematics performance based on the proposed statistics parameters optimization method, and the global linear isotropic performance index is 0.5, the global rotational isotropic performance index is 0.5, the global linear velocity transmission performance index is 1.012 3 m/s in the case of unit input matrix, the global rotational velocity transmission performance index is 0.102 7 rad/s in the case of unit input matrix, and the workspace volume is 1. The proposed research provides the basis for applications of the novel 5-DOF gasbag polishing machine tool, which can be applied to the modern industrial fields requiring machines with lower inertia, better kinematics transmission performance and better technological efficiency.     

新型5自由度并联机床运动学自标定研究

为提高并联机床的运动精度,提出了一种新的运动学自标定方法.该方法基于冗余传感器测出的动平台全部位姿信息,利用运动学反解公式,建立了标定数学模型,并应用遗传算法进行参数辨识,避免了大量的偏导计算.标定后机床X轴定位精度由标定前的士0.06 mm提高到士0.03 mm,Y轴定位精度由标定前的士0.43mm提高到±0.07 mm,Z轴定位精度由标定前的士0.94 mm提高到士0.07 mm.该方法为改善并联机床的运动精度提供了一种有效手段,并为并联机床的闭环控制奠定了基础.     

Dynamic analysis of the 2-DOF planar parallel manipulator of a heavy duty hybrid machine tool

This paper focuses on the dynamic characteristics of the two degree-of-freedom (DOF) planar parallel manipulator of a heavy duty hybrid machine tool. The Newton-Euler approach is employed to derive the inverse dynamic equation of the parallel manipulator. According to the motion planning of the cutting tool, dynamic simulation without cutting force is performed, and the ratio of the masses of counterweights to that of moving parts (not including the counterweight) is optimized. It demonstrates that the manipulator which is designed with over constraint can improve the dynamic behaviour. Furthermore, the cutting force model for face milling is introduced and the dynamic simulation with the dynamic cutting force is carried out. Simulation shows that the oscillation of cutting force is one cause of the vibration of the machine tool in the milling process. In the detailed design, some modification in the structure of the machine tool is made to suppress the vibration.     

A novel 5-DOF fully parallel kinematic machine tool

A novel 5-DOF (degree of freedom) fully parallel machine tool is presented in this paper. The parallel machine tool uses a compound limb to restrict the rotational degree of freedom of the moving platform, which is an unnecessary degree of freedom in the 5-axis machining process. The kinematics of the compound limb is illuminated especially. The closed-form solution is developed for the inverse kinematics. Due to the difficulty in comprehending the kinematics of the parallel kinematic machine tool, the movement of the moving platform in the fixed frame is also explained.     

基于知识的组合机床总体设计CAD系统的研究与开发

根据组合机床产品设计的特点,采用模块化设计思想,建立了组合机床总体设计CAD系统体系架构,系统的设计过程以自顶向下为主、自底向上为辅;研究了知识工程关键技术在系统中的应用,将组合机床总体设计的领域与经验知识和知识工程相结合,加强对设计知识的继承和重用,实现组合机床总体的快速设计,为组合机床设计提供了可靠的技术保障;最后介绍了系统开发平台和开发工具,并通过实例验证了系统可以显著提高组合机床产品设计效率和质量。     

基于模糊遗传算法的二自由度PID控制器优化设计

针对一般遗传算法中交叉概率和变异概率存在的选择困难问题，利用模糊推理系统来自适应估计交叉概率和变异概率，提出了模糊遗传算法（FGAs），并用于二自由度PID控制器参数寻优设计。仿真和实验表明，所设计的二自由度PID控制器可以使系统同时具有良好的目标值跟随特性和干扰抑制特性。     

机床的动态优化设计

1机床动态优化设计的现状关于机床动态性能的优化设计的研究,已有40多年的历史,国内外许多学者为此作了大量的基础性研究,开发研制了一批具有实用价值的理论、方法、测试手段和分析软件等,不仅使动态性能研究达到了很高的学术水平,也进行了大量实践应用研究,在高端数控机床的研发中,起到了很明显的作用.实践证明,在高端数控机床的研发中,动态优化设计是不可或缺的重要手段.但目前在国内实际机床研发中,还较少有意识地将已设计的工程方案进行动态优化,其主要原因有以下几方面:     

5-UPS/PRPU五自由度并联机床静力学分析

介绍了5-UPS／PRPU五自由度并联机床机构,通过对该机构进行静力学分析,建立了该机床的静力平衡方程和静力传递矩阵。对机床加工过程中的受力进行了具体分析,根据作用在动平台上的外力负载,可以得到5个驱动杆的受力大小和中间分支所承受的力偶矩大小,为该机床的结构设计、运动规划和动力学分析奠定了基础。     

数控机床中主轴变速箱的设计

社会注意市场经济的发展为我国工业生产创造了条件,在现代一体化生产模式中运用了很多先进的设备.对于数控机床而言,主轴箱是其最为核心的组织结构,整个主轴箱影响着数控机床的变速情况.大部分制造企业在实行技术改造时把重点放在了主轴箱变速器上,这是调整机床运行速度的重点.在设计过程中必须要对主轴箱的每个部件加以控制,这样才能确保数控机床主轴变速性能的良好.本文从数据机床主轴箱的主轴、Z轴、滚丝珠杆等方面进行设计,以对主轴箱性能加以改进.     

机床设计中的人性化

人性化设计已成为产品设计的一种主流。通过数控机床加工中心设计实践 ,分析其中的人性化设计 ,并完成了TH63 40卧式加工中心造型的改良设计 ,提高产品竞争力。     

机床静态精度设计与测量 “机床产品创新与设计”专题(七)

1高端数控机床的精度观念机床的基本功能是实现刀具与工件间的准确运动关系,以获得工件的精确尺寸和形状。所以机床从出现的第一天起,就存在着精度问题。静态精度是指机床在无外载荷条件下的几何和位置精度,包括基础结     

Optimal design of a 3-leg 6-DOF parallel manipulator for a specific workspace

Researchers seldom study optimum design of a six-degree-of-freedom(DOF) parallel manipulator with three legs based upon the given workspace. An optimal design method of a novel three-leg six-DOF parallel manipulator(TLPM) is presented. The mechanical structure of this robot is introduced, with this structure the kinematic constrain equations is decoupled. Analytical solutions of the forward kinematics are worked out, one configuration of this robot, including position and orientation of the end-effector are graphically displayed. Then, on the basis of several extreme positions of the kinematic performances, the task workspace is given. An algorithm of optimal designing is introduced to find the smallest dimensional parameters of the proposed robot. Examples illustrate the design results, and a design stability index is introduced, which ensures that the robot remains a safe distance from the boundary of sits actual workspace. Finally, one prototype of the robot is developed based on this method. This method can easily find appropriate kinematic parameters that can size a robot having the smallest workspace enclosing a predefined task workspace. It improves the design efficiency, ensures that the robot has a small mechanical size possesses a large given workspace volume, and meets the lightweight design requirements.     

机床开发中并行式面向环境设计的研究

针对现行传统的串行式机床设计方法所存在的问题,提出机床开发中基于并行工程的面向环境的设计模式、基本特性和关键技术,以提高企业产品开发设计能力,缩短开发周期,提高质量,降低成本,并增强机床的绿色程度.     

Post-processor development for a turning and milling composite machine tool

The accomplishment of a turning and five-axis milling in only one setup is extremely useful and is possible on a turning and milling composite machine tool. In this work, we present a control algorithm and develop a post-processor for this machine, which has six linear and three rotary axes. To calculate a generalized kinematics model, coordinate systems are established by analyzing the basic kinematic chain relation of the turning and milling composite machine tool. The two vectors, which control the motions of the cutter contact workpiece, are simultaneously transformed to provide the algorithms of the rotary angles and motion coordinate. A special post-processor written in JAVA language is developed according to the proposed algorithm. To evaluate the effectiveness and accuracy of the developed post-processor, a specimen (blade) is used in the cutting simulation and real machining experiment. Experimental results showed the effectiveness and accuracy of the proposed algorithm. Furthermore, Compatibility is improved by adding new functions such as change of target machine, cutter location data change, workpiece origin offset, and cutting feed rate control.     

中国经济发展和机床市场

一、中国经济发展和金属加工机床市场 2003年中国坚持执行扩大内需的方针,实行积极的财政政策和稳定的货币政策,加大对固定资产投资力度,发行1400亿元长期国债,在全球经济低迷不振,回复乏力的国际经济环境下和非典疫情的影响下,中国经济继续保持较快的发展,2003年上半年实现国内生产总值(GDP)50053亿元人民币,同比增长8.2%,与去年同期相比,还提高了0.4个百分点.     

工业设计在机床中的应用

沈阳机床在第六届中国数控机床展览会期间（CCMT2010）和第十二届中国国际机床展览会（CIMT2011）期间展出的产品都具有新颖时尚的外观，彰显了人性化的设计理念，将机械的刚性与艺术的柔性完美的结合在一起，适应了国际化市场现代化的时代趋势。在柔性化、个性化、可视化等方面达到完美的融合，将给国内外用户以全新的视觉冲击。这些机床展品给笔者留下了深刻的印象，也让笔者改变了对国产机床以往的观点和看法。     

二自由度PID控制器优化设计

遗传算法提供了一种复杂系统优化问题求解的通用框架,它通过对生物遗传和进化过程的模仿,来实现对问题的最优解的自适应搜索,本文应用改进的遗传算法(变因子),有效的克服了基本遗传算法应用中出现的问题,并针对二自由度控制器设计,运用改进的遗传算法,在MATLAB上进行了控制器参数的设计.