采用虚拟仪器的机床位移远程监测

机床位移状态是保障加工效率与加工精度的重要指标.实现多机床位移状态远程实时监测,对充分发挥机床效能、实现车间集成化管理具有重要的理论意义与实际价值.在系统功能分析基础上,采用虚拟仪器技术,开发了机床位移状态远程监测系统,在保障原有数控系统正常运行的同时,实现机床位移状态数据的实时采集、显示、存储及远程高速传输,为开发多路、多物理量的切削加工监测系统,研究基于网络的切削加工技术提供依据.     

基于工艺参数响应曲面的干式铣削机床能效分析

针对干式切削加工能耗相对较高的问题,通过对数控铣床干切削加工过程的实时功率进行数据采集,采用响应曲面方法描述和分析了数控铣削加工各主要工艺参数与单位切削能耗和机床能效之间的定量关系。通过工艺参数对单位切削能耗和单位机床能耗的响应曲面及降维平面进行了分析,结果表明,增大工艺参数和材料去除率对于提升机床能效具有积极作用。此外,降低机床基础能耗占比、提高切削能耗占比,能有效提高干式切削机床能效。     

高速切削机床的方案设计与应用

介绍了高速切削的特点和高速切削机床的结构,包括高速进给系统、高速主轴系统等,并对高速切削机床作总体方案设计。最后对高速切削机床的应用前景提出了展望。     

Rule-based cutting condition recommendation system for intelligent machine tools

This study relates to a rule-based cutting condition recommendation system for the implementation of intelligent machine tools. For cutting processes, information on the configuration and material of the work-piece, machine tools, and other related tools are essential, similarly as machine tools operators determine appropriate cutting conditions using their own experience along with such details. The development of computer technology has enhanced the intelligence of machine tools, allowing them to automatically calculate and determine relevant cutting data. In this study, a rule-based cutting condition recommendation system is implemented and installed on an open controller for intelligent machine tools. The cutting conditions utilized were provided by tool-makers. The conditions were recommended by classification into high-speed and common speed machining. Efficiency and accuracy has been improved by the implemented system, which is expected to be a key technology for the development of intelligent machine tools. This paper was recommended for publication in revised form by Associate Editor Dae-Eun Kim Seung Woo Lee received his B.S. degree in Industrial Engineering from INHA University, Korea, in 1989. He then received his M.S. and Ph.D. degrees from INHA University in 1991 and 2005, respectively. Dr. Lee is currently a Senior Researcher at the Intelligent Manufacturing Systems Research Division of the Korea Institute of Machinery & Materials in Daejeon, Korea. Dr. Lee’s research interests include Intelligent Systems, Energy Saving Equipment, and MES. Hwa Ki Lee received his B.S. degree in Nuclear Engineering from Seoul National University, Korea, in 1977. He then received his M.S. and Ph.D. degrees in Industrial Engineering from Texas A&M University, USA, in 1981 and 1984, respectively. Dr. Lee is currently a Professor at the Department of Industrial Engineering at INHA University in Incheon, Korea. Hiss research interests include Operation Research, Industrial System Simulation, Job Shop and Vehicle Routing scheduling.     

CNG车载瓶端部机械加工柔性组合机床的开发

针对传统CNG车载瓶加工缺少数控专机造成大质量CNG车载瓶加工质量较差和生产效率低下等技术问题,将基于移置式多轴机床的旋风切削、基于图像反馈的刀具切削路径误差补偿、面向绿色切削的雾化冷却技术等进行组合应用,开发了CNG车载瓶端部机械加工柔性组合机床,实现了高速平稳切削,快速可靠换刀,自适应性补偿缺陷,高效环保的刀具冷却。结果表明,组合机床的应用使得CNG车载瓶加工技术的自动化程度、加工精度和生产效率都得到了明显提高。     

一种数控切削机床运行能耗状态在线判别方法

机床运行能耗状态由一系列的能耗状态节点和能耗过程构成。针对至今仍存在一些关键状态节点无法判别等问题,提出了一种数控机床运行能耗状态在线判别方法。该方法基于数控机床运行能耗状态和状态节点的系统分析,并综合机床功率信息和数控系统通信信息,提出关键节点状态与过程状态在线判别方法,解决了切削加工开始、完成等关键节点和精加工状态判别等难题,从而实现了数控机床全部运行能耗状态的在线判别。在FANUC数控机床上进行的案例研究验证了该方法的有效性和实用性。     

Integration of cutting force control and chatter suppression control into automatic cutting feed adjustment system design

Abstract

This study designed an automatic cutting feed adjustment system for computer numerical control (CNC) turning machine tools, which integrate the operational characteristics of cutting force control and chatter suppression control to shorten the machining time and maintain the quality of workpieces. The setting of appropriate machining conditions (such as cutting feed, spindle speed and depth of cut) to consider both machining quality and efficiency often causes difficulties for machine tool operators. Therefore, this study uses cutting force control to design an automatic cutting feed adjustment method for cutting tools, and then, the chatter suppression control design is used to modify the cutting force command to suppress cutting chatter. The experimental results of the CNC turning machine tool show that the use of the cutting force control to adjust the cutting feed can shorten the machining time; however, the cutting chatter results in larger surface waviness on the workpiece surface. When the cutting force command is properly modified by actuating the chatter suppression control, the workpiece shows better surface roughness with prolonged machining time. Therefore, the cutting tests demonstrate that the proposed system is feasible for satisfying the machining requirements of the manufacturing processes of mechanical parts for high speed and high accuracy.     

Evaluation of machinability according to the changes in machine tools and cooling lubrication environments and optimization of cutting conditions using Taguchi method

This study analyze the effect of machine tools, cooling lubrication environments and cutting conditions on surface roughness and cutting force, and propose the combination of cutting conditions which minimizes the effect of machine tool variables on the dispersion of cutting force and surface roughness by treating the changes in machine tool itself and the installation environments as a noise factors. To do so, the Taguchi method is used to establish an experiment plan, and flat end milling is carried out to measure cutting force and surface roughness. The research results show that in the case of cutting force, the effect of cutting conditions is dominant, and changes in machine tools and cooling lubrication environments barely have effect on cutting force. However, in the case of surface roughness, all of the cutting conditions, machine tool and cooling lubrication environment variables have impact. In order to select a combination of cutting conditions insensible to changes in machine tools, considerations for feed per revolution and axial depth of cut turn out most important in the aspect of cutting force, and considerations for feed per revolution is most important in the surface roughness.     

Tool condition monitoring in an end-milling operation based on the vibration signal collected through a microcontroller-based data acquisition system

Machine condition plays an important role in machining performance. A machine condition monitoring system will provide significant economic benefits when applied to machine tools and machining processes. Development of such a system requires reliable machining data that can reflect machining processes. This study demonstrates a tool condition monitoring approach in an end-milling operation based on the vibration signal collected through a low-cost, microcontroller-based data acquisition system. A data acquisition system has been built through interfacing a microcontroller with a signal transducer for collecting cutting vibration. The examination tests of this developed system have been carried out on a CNC milling machine. Experimental studies and data analysis have been performed to validate the proposed system. The onsite tests show the developed system can perform properly as proposed.     

刀具磨损寿命分布规律的现场验证

通过对数控机床加工情况的现场调查，验证了关于刀具磨损寿命分布规律的研究成果，分析了刀具可靠性对切削加工过程的影响，建立了应根据刀具的可靠性来决定换刀间隔和切削用量，并提出了提高刀具可靠性的具体措施。     

五轴数控机床几何误差的建模与补偿技术

实时误差补偿技术是近代机床技术的研究重点,多轴数控机床的误差补偿问题有很高的难度和研究价值。本文提出了基于多体系统的五轴数控机床几何误差建模技术,研究了误差补偿的关键,即表示几何误差的参数,同时为了评估建模的好坏,研究了基于多体系统的切削工件过程仿真。     

德国伊萨切割机的故障分析和维修技巧

数控切割机是机械工业中常见的设备,数控机床是一种高科技含量、高精度要求,专门用于加工复杂曲面零件的机床,这种机床的数控系统对一个国家的航空、航天、军事、科研、精密器械、高精医疗设备等行业,有着举足轻重的影响力.     

The influence of the metal working fluids on machine tool failures

The coolant system for metal working is a typical example of a tribomechanical system, where several wear mechanisms are present simultaneously. The metal particles in the coolant system have the appearance of tiny chips, grains, coils of fine wire and so on. Particulate composition varies significantly depending on the cutting process and operating conditions, as well as coolant characteristics and coolant systems. During the cutting process, the metal working fluid is also exposed to changes due to: chemical reactions between its substances; tool surfaces and workpieces; the presence of particles and high temperatures on contact surfaces.The aim of the present work is to study the tribological processes, wear and failures on tribomechanical system elements of machine tools by exposing them to fluid for metal working with particles. The experimental investigations of effect of metal working fluids on tribological processes of tribomechanical system elements have been carried out at a metal working factory. The investigations were carried out on 30 lathes in four periods of time. The obtained results have proved that water based metal working fluids have quite a great influence on tribological processes, wear and failures of tribomechanical system elements of machine tools.     

CIMT’97主要展品的技术特点综述

两年一度的中国国际机床展览会是国际机床界和我国机械制造业的一件盛事。第五届中国国际机床展览会(CIMT’97)又一次荟萃了国内、外各机床厂及相关配套件厂和工具厂的精华,既可看到一些名牌企业享有盛名的产品,也会发现一些脱颖而出的新秀企业所展示的精品。从展览会上我们能深刻地领会到机床工具行业的发展动向,也能生动地观察到琳琅满目的新产品和新结构。从中既反映了丰富多采的世界先进实用制造技术和最新制造技术,也展示了中国机床工具行业通过“三大战役”在增强开发能力和竞争实力方面所取得的可喜的巨大进步。     

高速数控铣削的机床刀具及编程技术

分析了高速数控铣削的机床、刀具及编程中的特点及技术要点,提出了高速数控铣削机床结构、刀具系统及基于CAM的高速数控铣削编程技术的策略,实践证明,效果良好.     

Monitoring and control of tools in multifunctional machine tools

Machining centers and multifunctional machine tools are used in computerized integrated production. They are equipped with a large number of cutting tools for production of a specific batch of parts. In such automatic systems, monitoring and control systems replace the human operator. Monitoring of the state of machining systems is essential today in monitoring and control of the machining operations [1, 2]. It is important to create monitoring systems to support reliable tool operation in multifunctional machine tools. The goals of such systems are to minimize the damage from serious disruption of tool operation and to ensure timely tool replacement. To that end the multifunctional machine tools and/or the numerical control system must be equipped with sensors and various monitoring devices. A strategy must be developed for the prevention of disruption of the machining process and tool failure.     

The mathematical models of the basic entities of multi-axis serial orthogonal machine tools using a modified Denavit–Hartenberg notation

The use of virtual techniques as a means of training operators and familiarizing them with the machine tools on which they work has become increasingly widespread throughout the manufacturing industry in recent years. To support the development and implementation of virtual machine tools, this paper constructs the generic mathematical models of the basic building links, joint types, and cutting tools of multi-axis serial orthogonal machine tools. The modeling methodology can support the synthesis of various machine tools with different configurations but similar functions and facilitates the processes of error analysis, numerical control data generation, parameter measurement, and cutting kinematics analysis. The validity of the modeling approach is demonstrated using a six-axis serial orthogonal machine tool for illustration purposes.     

振动切削机理研究及应用

提出机床传统切削存在的问题及振动切削对机床研究的重要性，介绍了振动切削的机理，特点，并指出振动切削的研究是精密切削和超精切削的一个重要的发展方向。     

Influence of the phase composition and microstructure of plasma cladding Fe-Cr-Ni-C alloy coating on residual stress and crack formation

Tool path generation is one of the key challenges in multi-axis sculptured surface machining. Besides geometry accuracy, machining processes have been considered in tool path generation in order to improve machining quality and efficiency as far as possible. However, so far, the machine tool accuracies have not been yet fully taken into account during tool path generation. Contour accuracy is one of the most important precision indexes to guarantee the machining quality of sculptured surfaces. One of the major reasons causing contour error is the dynamic mismatch between feed axes of machine tools. In this study, the mathematic relationship between the cutting direction, dynamic mismatch of feed axes and contour error is theoretically established. The mathematic relationship can be used to calculate the optimal cutting directions which minimize the contour error caused by dynamic mismatch between feed axes during machining a sculptured surface by a three-axis machine tool. A machining experiment is carried out to verify the mathematic relationship. In the experiment, the tool paths are generated along the optimal cutting direction and other cutting directions for comparison. The results show that the contour error under the case of the optimal cutting direction is much smaller than that under the other cases.     

基于PLC的数控机床电气控制系统研究

数控机床在解决复杂、精密零件的加工方面起到了重要的作用,是具有典型机电一体化系统的数控机床。基于PLC的数控机床电气控制系统是数控技术发展的必然结果。PLC数控机床在应用中有很多优点,例如,电气控制系统通过采用工件自动夹紧、断刀检测和机械手自动换刀等实现了数控机床的自动化。本文探讨了加工中心的电气控制技术和设计方法,对确保机床的安全可靠,提高加工精度和生产率具有重要意义。