石墨碳块复合加工机床及碳块自动输送装置的研制

为实现核能内构件石墨碳块的复合加工及毛坯自动输送,设计专用设备.通过分析碳块的加工工艺及确定设备整体方案,对其内部的机械结构采用等强度可靠性设计方法,选用高精度、质量可靠的机床配套件,实现碳块复合加工及坯料输送的自动化.从原理和结构上对复合加工机床的配置、输送系统的设计要点进行了较为详细的论述.该设备已在加工单位调试使用,效果良好,满足用户对碳块加工精度及整机自动化的要求.     

石墨碳块机加工夹具系统的设计

分析核能内构件石墨碳块的加工工艺、工装夹具的结构及设计原则,设计自动加工专用夹紧工装,该工装是能够将工序一与工序二工装组装在一起的套装夹具,解决了碳块加工过程中由于重复定位装夹而产生的误差累积,保证了碳块的加工精度。在加工单位调试使用的效果良好,可满足对碳块加工精度的要求。     

减少机床热变形方法的研究

机床在各种热源的作用下,产生热变形,影响工件与刀具之间的相对位移,造成加工误差,从而影响零件的加工精度。所以,减少机床热变形对提高机床加工精度是极其重要的。本文对机床工艺系统的主要热源进行了分析,并对减少机床热变形的方法及国内外研究的现状进行了讨论。     

用超精密线切割加工机床加工模具

当前,对于线切割加工机床,提出了进一步实现高精度化、加工自动化、无人化及采用CAD/CAM 等完整加工系统,以使其加工性能和功能产生飞跃发展的要求。本文将介绍超精密线切割加工机床 EWP-300A 及加工实例。线切割机床加工精度的因素包括机械系统、放电方式和它们的控制系统,以及工件与加工环境等。这些因素各自独立地或互相关联地对加工精度产生影响,因而实现高精加工的条     

石墨高速加工机床的发展现状

总结了石墨高速加工机床的特点,详细介绍了目前常用的国外石墨高速加工机床的主要机型及其基本性能,为石墨高速加工机床选型提供依据.     

枪钻机床的特点和设计

枪钻机床是一种深孔加工机床 ,在机床结构上与传统的钻镗类组合机床有很大的区别 ,具有自己的特点 :如刀具切削时独特的受力形式 ,排屑方法 ,对机床和切削液的特殊要求等等。枪钻机床用来加工深孔加工深度一般可以做到枪钻直径的 10 0倍 ,采取措施以后可以达到直径的 2 0 0倍以上。另外枪钻加工可以达到的精度很高 ,视不同的被加工材料和选用不同的切削用量可以一次加工出精度很高的孔 ,孔径精度可以达到ＩＴ7以上 ,粗糙度可以达到Ｒａ6.3～Ｒａ0 .4 ,直线度最高可以达到 0 .1/ 10 0 0。由于枪钻的这些特点 ,因此现代枪钻机床不但用来加工深…     

电磁断屑器

在金属切削机床加工中 ,铁屑不易折断已成机械加工中普遍问题 ,尤其在加工塑性金属材料时 ,形成的带状屑 ,有时缠绕在工件或刀具上 ,拉伤工件表面或打坏切削刃 ,甚至伤人 ,影响已加工表面的光洁度 ;而在加工铸铁等脆性材料时 ,切屑崩碎或碎片飞溅伤人 ,并易研损机床滑动表面。为了克服断屑不畅带来的负面影响 ,经过长期研究和反复实践 ,我们提出了“电磁自动断屑器”新课题。1　电磁断屑器的结构原理电磁断屑器是利用电磁铁原理 ,即插入铁蕊的通电螺线管构成一个电磁铁 ,铁蕊在通电螺线管中被磁化 ,产生磁场 ,于是 ,通电螺线管的周围既有电…     

基于有限元分析的机床导轨热变形研究

高速高精度机床切削加工过程中,在多种热源的作用下导轨会产生热变形,影响工件与刀具间的相对位置,造成加工误差。找出导轨热位移较大的点,并分析其对加工精度的影响,对于减小加工误差提高加工精度至关重要。文章在对导轨热边界条件进行分析的基础上,应用有限元分析方法,建立了一类机床导轨的有限元热变形分析模型,并进行了热变形分析计算,为分析导轨的热变形对加工精度的影响提供了依据,并为机床综合热误差补偿提供参考。     

曲轴轴端内孔加工组合机床的设计

在现代加工业中，组合机床在提高产量和保证质量等方面起着重要作用。论文主要从机械、电气、液压等几个方面简要介绍曲轴轴端内孔加工组合机床的设计思路与实现、该机床采用移动工作台实现双工位、双向工作进给，工作随夹具移动，以缩短辅助工作时间，提高工作效率；其特点还在于任一工位可单独实现自动循环加工。机床夹具采用液压夹紧，工作用V型块定位，为了在磨损后更换方便，设计时对V型块和定位块的尺寸精度及行位公差提出严格的要求。     

机床转台角度与偏心误差的分析与校正

机床转台的几何精度对零件的加工精度产生很大影响。针对转台在运行时所产生角度误差和偏心误差,提出旋转台误差的分离方法。通过配合使用常规测量工具水平仪和角摆仪,快速检测和校正旋转台几何误差,从而减小机床转台的加工误差。通过实验验证校正前后机床转台角度的定位误差。结果表明：校正后转台的定位精度提高了23%,证明该校正方法能够有效提高机床转台的几何精度,而且操作简便、成本低。     

Multi-functional machine tool

The functions of metal cutting machine tools have been increasing to meet the demands of high productivity and high accuracy in machining complicated and difficult parts on one machine. This paper presents a comprehensive survey of multi-functional machine tools used for metal cutting, and their kinematic configurations, control and programming technologies. Design principles and assessment of multi-functional machine tools are discussed mainly taking examples of 5-axis machining centers. The paper also presents examples of latest multi-functional machine tools as well as current status of related supporting technologies.     

Energy optimized jerk-decoupling technology for translatory feed axes

Dynamic feed axes for machine tools are usually optimized for high jerk rates. This, however, might lead to excitations of the machine frame due to reaction forces of the linear motor. This paper describes the development of a jerk-decoupled feed axis with an innovative guidance system and energy-optimized spring-damper-elements. An accomplished system simulation is based on an energy observer applied to accomplish the energy-optimal design of an example jerk-decoupled feed axis. The simulatory results are verified at a test bed using adjustable adaptronic components. A concluding verification proves the positive effects of this technology without negative effect on the accuracy.     

Development and Application of a Direct Drive Motor for Performance Enhancement of Versatile Machine Tool Systems

For highly productive machining operations, multi-axis versatile machine tools are drawing more attention in today's market. In order to maintain the stability and the motion accuracy over a long operation time, it is important for such a versatile machine tool to avoid complicated mechanisms, such as an indirect drive, from the viewpoint of machine design. This paper presents a design methodology for the specification of a direct drive (DD) motor to enhance the overall performance of versatile machine tools. Practical application examples to different types of machine tools are also presented.     

数控机床热误差建模及预测方法分析

热误差作为制约数控机床加工精度的关键因素,在重型数控机床上表现得尤为明显。以重型落地镗铣床为例,根据热误差测量试验数据,分析重型数控机床温度场特性,并基于兼顾相关系数和欧式距离的系统聚类准则,对温度测点系统进行优化,以减小温度测点间共线性。通过优化温度测点,采用多元线性回归分析,建立重型数控机床热误差预测模型。由现场试验可知,建立的热误差预测模型可将均方根误差控制在10μm以内,有效地提高了热误差预测精度。     

Adaptive preloading for rack-and-pinion drive systems

In the field of machine tools, rack-and-pinion drive systems are one of the commonly used feed drive systems. In order to achieve the high accuracy specifications of modern production facilities, these drives are electrically preloaded to reduce backlash in the drive train. In most cases, the preload is fixed, even though the method of electrical preloading allows adjustment during operation.This paper describes a novel approach – called adaptive preloading – to adjust preload during operation. The objective is to increase the drive system’s energy efficiency by continuously adapting the preload, which is minimally required for maintaining the drive system’s accuracy.     

A general approach for error modeling of machine tools

This paper presents a general and systematic approach for geometric error modeling of machine tools due to the geometric errors arising from manufacturing and assembly. The approach can be implemented in three steps: (1) development of a linear map between the pose error twist and source errors within machine tool kinematic chains using homogeneous transformation matrix method; (2) formulation of a linear map between the pose error twist and the error intensities of a machine tool; (3) combination of these two models for error separation. The merit of this approach lies in that it enables the source errors affecting the compensatable and uncompensatable pose accuracy of the machine tool to be explicitly separated, thereby providing designers and/or field engineers with an informative guideline for the accuracy improvement by suitable measures, i.e. component tolerancing in design, manufacturing and assembly processes, and error compensation. Two typical multi-axis machine tools are taken as examples to illustrate the generality and effectiveness of this approach.     

Mechatronic Systems for Machine Tools

This paper reviews current developments in mechatronic systems for metal cutting and forming machine tools. The integration of mechatronic modules to the machine tool and their interaction with manufacturing processes are presented. Sample mechatronic components for precision positioning and compensation of static, dynamic and thermal errors are presented as examples. The effect of modular integration of mechatronic system on the reconfigurability and reliability of the machine tools is discussed along with intervention strategies during machine tool operation. The performance and functionality aspects are discussed through active and passive intervention methods. A special emphasis was placed on active and passive damping of vibrations through piezo, magnetic and electro-hydraulic actuators. The modular integration of mechatronic components to the machine tool structure, electronic unit and CNC software system is presented. The paper concludes with the current research challenges required to expand the application of mechatronics in machine tools and manufacturing systems.     

Predictive simulation of damping effects in machine tools

A predictive simulation of the different damping effects in machine tools is required to optimize the dynamic behavior and thus increase their performance and working accuracy. Previously, holistic optimization based on damping was not possible due to non-predictive damping models and the lack of adequate modeling approaches. This paper presents a modeling approach, which allows the efficient simulation of the dynamic behavior. By applying this procedure and suitable damping and friction models, the dynamic behavior of a four-axes machining center was simulated with high accuracy – FRAC values above 95% were achieved.     

Mechanical module interfaces for reconfigurable machine tools

Reconfigurable manufacturing systems (RMS) enable industrial companies to adapt to frequent and unpredictable changes of production requirements in a cost-efficient way. RMS are constituted by modular machine tools that provide variable overall functions with the ability to add, remove, rearrange and replace functional sub-units. The performance of these machine tools as regards the quick and flexible arrangement of modules and high work piece quality strongly depends on the properties of the mechanical module interfaces. In this paper, performance parameters for mechanical module interfaces were defined and their influence on the machine tool’s performance discussed. Then flexibly arrange-able quick-coupling interfaces as a promising solution for module assembly were analyzed. Finally, tools for the determination for those interface performance parameters are presented, which require technical testing.     

Evaluation of electromagnetic guides in machine tools

Guides in machine tools aim for high accuracy, stiffness and damping. However, these characteristics are mainly limited by the working principle. In this paper, the implementation of electromagnetic guides in linear machine tool axes is evaluated. A milling machine prototype, with the opportunity of using ball guides or electromagnetic guides in the z-axis, is employed. Primarily, working principle and properties of the electromagnetic guide are presented and analyzed. Operating behaviour, stiffness and damping of the two guiding principles are compared. The electromagnetic guide is finally assessed in the milling process and beneficial functions of the system are presented.