Body diagonal error measurement and evaluation of a multiaxis machine tool using a multibeam laser interferometer

The International Journal of Advanced Manufacturing Technology - To comprehensively evaluate the accuracy and performance of machine tools, in this paper, a novel measuring method for the body...     

数控机床位置检测的研究

数控机床位置检测应用很广泛,并且很重要.通过数控机床位置检测,其中检测装置包括光电编码器和光栅,掌握光电编码器和光栅的结构、原理,编程方式及仿真等方面和特点,建立感性知识.能够更好的对数控机床位置检测装置加以应用.     

数控机床位置检测元件检修注意事项

阐述娄控机床位置检测元件的维修注意事项及进口件用国产件的替代。     

机床夹具综合定位误差方程及其应用

提出了机床夹具综合定位误差的概念，给出了计算的方程式，应用实例，说明了其应用。     

并联机床位置控制卡局部总线接口设计

针对传统ISA总线位置控制卡由于带宽限制，数据传输速度慢，限制了主机的处理能力等缺陷，设计了基于PCI总接接口的并联机床高性能位置控制卡，打破了数据传输的瓶颈，大幅度地减轻主机负担，有效的提升系统整体性能。     

一种新的机床位置误差灵敏度分析方法

本文提出一种新的机床位置误差灵敏度分析方法。首先基于多体理论和齐次变换矩阵建立了五轴龙门机床位置误差模型。其次通过截断傅里叶技术来表征与位置有关的几何误差参数,每个误差参数对位置误差的灵敏度值可表示为其傅里叶幅值平方。然后归一化处理,关键的几何误差参数为第2,3,8,15和26项误差。通过与传统的Sobol法对比,仿真结果表明两种灵敏度分析方法辨识的关键几何误差相同且灵敏度值相近。此外,本文提出的灵敏度分析计算效率优于传统Sobol法。最后为了验证关键几何误差的有效性,提出了一个关于机床关键几何误差的补偿实验。实验结果表明,补偿关键几何误差后机床的加工精度提升了48%。因此,本文提出的机床位置误差灵敏度分析方法是可行的和有效的。     

CY-K52数控机床进油管位置的改进

针对CY-K52数控机床叶片泵进油口位置与进油管位置不对中,造成叶片偏斜、刮研缸壁、叶片泵损坏的情况,对进油管位置进行了改进,使进油口位置与进油管位置对中,叶片泵工作正常,提高了生产效率。     

并联机床工件位姿测量

因为并联机床的虚实轴之间的非线性关系，使得并联机床工件定位方法不同于传统机床。研究了并联机床工件位姿测量的基本方法，并给出了相关的计算公式。按这些方法设计的工件测量软件模块在并联机床工件测量中得到运用。     

数控机床用模糊型位置控制器的研究与实现

针对数控机床位置控制精度高、实时性强和动态响应特性好的需求，提出了相应的位置模糊控制系统（PFCS）架构。为了兼顾伺服系统稳态精度和动态响应性能指标，对传统的基本型模糊控制器（FC）进行了改进与完善，提出了带智能积分和修正因子的位置模糊控制器（PFC），以及双模（FC＋PID）智能协调控制策略。最后，经过数字仿真结果和实际单轴伺服系统的使用表明，获得了比较理想的综合控制效果。     

新型混联虚拟轴机床的位置正解与工作空间分析

提出了以三自由度空间并联机构作为主进给机构，辅以双向移动工作台实现多坐标数控加工的一种新型混联虚拟轴机床的配置方案。建立了空间并联机构位置正解的封闭方程，分析了空间并联机构及其虚拟轴机床的工作空间，并给出了数值实例。     

全气控气动卧式三面双工位钻孔、铣槽组合机床的设计

问题的提出及设计方案的确定我公司燃气灶中气阀芯（见图１）从单轴纵切自动车床加工后,仍有２个孔、３条槽需要加工。以前加工的工艺方法是用仪表车床开槽,用台钻钻孔,分５道工序完成。这种加工方法存在以下缺点：①因多次定位,零件加工精度难以保障;②生产效率低,完成这５道工序需５台机床,５个工人,生产节拍为４０ｓ;③自动化程度低。为了解决这些问题,我们设想把这５道工序合为１道工序,安排在同一机床上１次装夹完成加工。根据被加工件为铜材,材质较软,切削力小的特点,设计了１台采用全气控气动加工卧式三面双工位钻钻…     

Lapping machine with a cycloid tool trajectory

A lapping machine with a cycloid tool trajectory is proposed for precision plane finishing. The configuration of the machine is described, as well as the kinematics of the primary motion and the forces pressing the parts against the tool. Methods of controlling the density of the network of tool tracks are presented. To boost the productivity and final surface quality, a trajectory with high cutting speed—for example, a cycloid tool trajectory with a low density of tool tracks—is specified at the beginning of machining parts and then, as the margin is removed and the flatness of the machined surface is improved, the density of the network of machining tracks is increased to form the required microrelief.     

Uncertainty analysis of positional deviations of CNC machine tools

The assessment of the measurement uncertainty is an indispensable task in all calibration procedures. By international accord, the evaluation is to be done in accordance with the ISO Guide to the Expression of Uncertainty in Measurement (GUM). To calibrate the positional deviations of computer numerically controlled (CNC) machine tools, calibration laboratories will usually follow the guidelines in ISO 230-2 International Standard. However, that standard does not address uncertainty. In this paper, we present an uncertainty evaluation scheme that is firmly grounded in the GUM, and can therefore be of use as a guide to develop appropriate uncertainty calculations in this and similar types of calibrations.     

Minimizing the number of tool switches on a flexible machine

This article analyzes a tool switching problem arising in certain flexible manufacturing environments. A batch of jobs have to be successively processed on a single flexible machine. Each job requires a subset of tools, which have to be placed in the tool magazine of the machine before the job can be processed. The tool magazine has a limited capacity, and, in general, the number of tools needed to produce all the jobs exceeds this capacity. Hence, it is sometimes necessary to change tools between two jobs in a sequence. The problem is then to determine a job sequence and an associated sequence of loadings for the tool magazine, such that the total number of tool switches is minimized. This problem has been previously considered by several authors; it is here revisited, both from a theoretical and from a computational viewpoint. Basic results concerning the computational complexity of the problem are established. Several heuristics are proposed for its solution, and their performance is computationally assessed.     

机床床身导轨的磨损及其对机床精度的影响

介绍机床床身导轨的精度对机床精度有决定性影响，它直接影响被加工零件的尺寸、形状和位置误差值；导轨的磨损是造成机床床身导轨精度下降的根本原因，并以不同的形式对被加工零件的误差产生影响；导轨的磨损包括磨粒磨损、粘着磨损和腐蚀磨损等，在不可避免的情况下，介绍所采取的一些措施。     

6自由度并联机床位姿误差线性化计算模型及验证

文章建立了两种6自由度并联机床位姿误差计算模型：基于机构位姿方程与运动学反解方法的线性化计算模型和基于支链杆长方程与运动学正解方法的非线性计算模型。在几何误差为小误差时,应用两种模型计算得到的机床位姿误差的变化规律与误差量值均十分接近。非线性模型比较精确地反映了位姿误差与几何参数误差之间的非线性映射关系,但因显式关系无法获得、计算繁琐而不便应用;线性模型则通过近似处理,建立了位姿误差与几何参数误差之间的线性显式关系,故可作为机床位姿误差的计算模型应用于精度分析与设计、运动学标定等与精度问题相关的分析工作之中。     

加速发展数控机床功能部件推动数控机床产业化

数控系统、电主轴和高速精密主轴单元、刀库和机械手、数控刀架、数控转台、滚珠丝杠副、直线电机等功能部件和电、液、气配套元件是数控机床的重要组成部分,是发展数控机床的基础。提升我国数控机床产业化水平,功能部件必须要进一步加快发展,夯实我国数控机床的基础。进入21世纪,我国数控机床取得了快速发展,2002年数控金属切削机床产量达24803台,比2001年同比增长了31.6％。数控机床的可供品种超过了1000种,掌握了代表     

Assessment of the tool post reliability of a high-stiffness turning machine

Reliability refers to the ability of a part, device or system to conduct an intended function in a given condition for a certain period of time. A mechanical system or structure such as a machine tool exercises the capacity of the entire system with regard to the various constituent parts that are connected to each other; as such, the reliability of the parts constituting the system determines the reliability of the entire system. A tool post is a device designed to efficiently provide the tools necessary for the processing of a turning machine: the parts used in a hard turning machine which requires higher stiffness must provide greater reliability. For the purposes of this study, the reliability of a tool post, which has the highest failure rate of a turning machine system, was assessed. In order to conduct a reliability assessment of a given tool post, reliability prediction using a failure rate database, weak point analysis, the manufacture of a reliability tester and the calculation of reliability testing and quantitative reliability criteria were also carried out. By so doing, the failure rate, the MTBF (Mean time between failures) and other factors could be calculated. Furthermore, the results can also be applied to other parts of the turning machine or to a reliability assessment of a subsystem by using the suggested assessment method.     

世界机床工业发展的特点

机床工业产值虽然只占世界GDP的0.07%,但却在世界制造业和工业中扮演着极其重要的角色,在国民经济中占有重要的战略地位.通过研究分析,我们发现世界机床工业有如下几个特点:1)本土机床工业与本土制造业、工业高度相关;2)机床工业国际化程度很高;3)单个国家国内机床需求波动剧烈,世界总机床需求相对平稳;4)机床工业产业集聚效应显著;5)家族企业是世界机床工业流行的所有制模式.