Design of High Precision CNC Vertical Lathe Turning Tool Holder

A large aspect ratio vibration reducing tool holder based on passive damping vibration reduction technology is designed to solve the vibration problem that occurs in deep hole machining of vertical lathes.A dynamic model of passive damping vibration reduction tool holder was established,and the optimal damping ratio,optimal frequency ratio,and maximum relative amplitude were derived.Modal analysis of the passive damping vibrationreduction tool holder was conducted using software.The results showed that the maximum response amplitude of the passive damping vibration reduction tool holder decreased significantly compared to the original one.

A Reliability Allocation Method of CNC Lathes Based on Copula Failure Correlation Model

The current research of reliability allocation of CNC lathes always treat CNC lathes as independent series systems. However, CNC lathes are complex systems in the actual situation. Failure correlation is rarely considered when reliabil?ity allocation is conducted. In this paper, drawbacks of reliability model based on failure independence assumption are illustrated, after which, reliability model of CNC lathes considering failure correlation of subsystems is established based on Copula theory, which is an improvement of traditional reliability model of series systems. As the failure time of CNC lathes often obeys Weibull or exponential distribution, Gumbel Copula is selected to build correlation model. After that, a reliability allocation method considering failure correlation is analyzed based on the model established before. Reliability goal is set first and then failure rates are allocated to subsystems according to the allocation vector through solving the correlation model. Reliability allocation is conducted for t = 1. A real case of a CNC lathe and a numerical case are presented together to illustrate the advantages of the reliability model established consider?ing failure correlation and the corresponding allocation method. It shows that the model accords to facts and real working condition more, and failure rates allocated to all the subsystems are increased to some extent. This research proposes a reliability allocation method which takes failure correlation among subsystems of CNC lathes into consid?eration, and costs for design and manufacture could be decreased.

Applied research on reliable increase measures of CNC lathes

According to the reliable data of sixteen CNC lathes, each reliable index of the serial CNC lathes is evaluated before tackling and after tackling. According to the failure analysis, reliable improvement measures of the serial CNC lathes are put forward.

Comprehensive Reliability Allocation Method for CNC Lathes Based on Cubic Transformed Functions of Failure Mode and Effects Analysis

Reliability allocation of computerized numerical controlled（CNC）lathes is very important in industry.Traditional allocation methods only focus on high-failure rate components rather than moderate failure rate components,which is not applicable in some conditions.Aiming at solving the problem of CNC lathes reliability allocating,a comprehensive reliability allocation method based on cubic transformed functions of failure modes and effects analysis（FMEA）is presented.Firstly,conventional reliability allocation methods are introduced.Then the limitations of direct combination of comprehensive allocation method with the exponential transformed FMEA method are investigated.Subsequently,a cubic transformed function is established in order to overcome these limitations.Properties of the new transformed functions are discussed by considering the failure severity and the failure occurrence.Designers can choose appropriate transform amplitudes according to their requirements.Finally,a CNC lathe and a spindle system are used as an example to verify the new allocation method.Seven criteria are considered to compare the results of the new method with traditional methods.The allocation results indicate that the new method is more flexible than traditional methods.By employing the new cubic transformed function,the method covers a wider range of problems in CNC reliability allocation without losing the advantages of traditional methods.

Importance Analysis on Subsystem of CNC Lathe Based on TOPSIS

An importance analysis model for computer numerical control（CNC）lathe subsystems was proposed.The model was based on technique for order preference by similarity to an ideal solution（TOPSIS）and considered the structure correlation between subsystems and the complete machine,the fault correlation of each subsystem and so on.The model can obtain a comprehensive sequencing of subsystems based on their importance to the complete machine.It lays a theoretical foundation for reliability allocation.

Reliability evaluation on CNC lathes based on the modified L-M method

Equivalent ways commonly used in engineering works are not effective to estimate the reliability of tandem system based on L-M method. One modified L-M method is an important means to estimate the reliability of CNC lathes. A method of using two named confidence limits for the estimation is put forward. Fitting resuits of the sub-systems of CNC machine tools are estimated. And the scattered level of confidence limits facing the reliability matrix of sub-systems can be clearly seen.

数控车床常见问题及解决方案的探索与研究

数控车床具备高精度的加工技术,作为新时代的产物,在现代加工中的地位越来越突出,使用的频率也越来越高。在高频繁使用中不可避免地会出现各种各样故障,设备故障出现后如果无法及时排除,不仅会严重影响零件的加工精度,甚至造成事故。因此,数控车床故障分析、预防措施及排除方法具有重要的意义。

数字孪生驱动的数控车床主传动系统故障诊断研究

数控车床主传动系统是机床的核心部件,其一旦发生故障会造成加工质量甚至作业安全问题。数字孪生技术能降低故障诊断的难度,但目前研究仍存在物理实体到虚拟实体转换效率低和神经网络过拟合问题。为了解决上述问题,提出一种基于数字孪生和正则化BP神经网络的故障诊断方法。建立数控车床主传动系统数字孪生模型,通过OPC UA通信完成了物理实体和虚拟实体间孪生数据的交换,对比分析正则化改善过拟合问题的4种方法,构建了丢弃法正则化BP神经网络故障诊断模型。通过对比不同信噪比下BP神经网络、丢弃法正则化BP神经网络和卷积神经网络的损失函数和预测准确度,验证了诊断模型的可行性和算法的适用性。

经济型数控车床自动化制造单元的设计

针对现有经济型数控车床的上下料、抓取、装夹动作依赖于人工的问题,提出了改进设计方案。设计了上下料装置、抓取装置、零件装夹装置、料盘装置等机构,采取伺服电动机和气缸驱动形式,借助PLC和PMC控制程序,实现数控车床自动上下料、语音报警、自动加工等功能,加快了生产节拍,稳定了产品质量,可满足数控机床单机设备生产过程的自动化需求。

基于G71外圆粗车复合循环指令的对刀原理

以CJK6032教学型数控车床车削轴肩为例,针对常用的G71外圆粗车复合循环指令的使用特点及工件坐标系与机床坐标系的转换关系,详细论述了该指令的数控编程方法及对刀原理,为提高数控编程效率及加工精度、掌握对刀技巧提供参考。

CNC车床的故障概率模型

本文从ＣＮＣ车床的故障数据的采集入手，建立了ＣＮＣ车床的故障数据库。

CNC车床维修性水平的评价

通过对现场采集的226条数控车床维修时间数据的分析,建立了其维修时间的分布模型,CNC车床维修时间服从对数正态分布,从而得出了其维修性特征函数(维修度函数M(t)、概率密度函数m(t)、维修率函数μ(t))。在此基础上对CNC车床的维修性水平进行了评价。

CNC车床螺纹加工的插补方法

针对ＣＮＣ车床螺纹加工时存在的问题。

运用CAXA电子图板解决CNC车床编程中的难点问题

通过对计算机数控车床手工编程常见难点问题的分析,提出了利用 CAXA电子图板软件的绘图、编辑、工程标注、坐标查询等功能直观形象地提高数控编程精度、效率和工艺合理性的新方法。阐述了 CAXA 电子图板在数控工艺处理、图形数学处理、刀具干涉分析、编写数控程序、校验调试与仿真运行数控程序等编程阶段的应用技巧和应用特点,并通过编程实例予以详细说明。

机械制造技术中数控技术运用分析

本文首先对数控技术的概念、组成及工作原理进行概述,然后重点分析了数控技术在机床领域中的具体应用情况。文中以数控车床和数控铣床为例,从控制原理、运动控制等方面详细阐述了数控技术如何实现对机床高效、精密的运动控制,以满足汽车行业的高质量加工需求。数控技术可以极大提高机械加工的自动化水平,使机械制造向精益求精的方向发展。

面向造纸辊轴的数控车床编程参数优化研究

造纸辊轴质量本质上取决于数控车床加工程序,因此在车床数控化率日趋攀升的推动下,满足数控车床快速编程与高效加工的个性化需求值得探究。而由于数控车床缺乏非圆曲线插补功能,因此实际生产过程中椭圆与抛物线等典型非圆曲线编程需以宏程序加以实现。由此,基于造纸辊轴加工需求与椭圆曲线方位,针对性设置了数控车床编程参数,以计算与生成了数控车床宏程序。此数控车床宏程序不仅能提高造纸辊轴加工精确度与加工效率,还可优化加工工序,消除加工空行程,兼具可靠性与通用性。

数控车床加工精度的影响因素分析及对策

数控车床工艺与技术在机械加工制造领域中的推广和应用,促进了机械产品加工精度的有效提升。由于数控车床精度对机械产品加工精度有着决定性影响。所以,机械加工企业对数控车床工艺与技术发展的关注度也越来越高。机械加工企业应紧跟数控车床工艺技术发展的潮流,加大影响数控车床精度因素研究分析的力度,并以此为基础制定和实施有助于数控车床加工精度提升的策略,为机械加工企业的健康可持续发展保驾护航。基于此,针对数控车床加工精度的影响因素进行分析。

基于包络解调分析法的数控车床镗孔振纹分析与改进

针对数控车床镗孔表面振纹问题,文章采用由简至繁的原则,初步确定振纹故障来源,并利用卡盘浮动支撑工装来间接提高主轴刚性和缓解刀纹的深度,排除加工振纹与主轴关联;利用包络解调分析法,通过LC-810型振动信号采集分析仪对主轴前端和后端振动信号进行采集,均值分别在22.37 Hz、45.94 Hz;与NN3048和NU1038轴承故障特征频率22.127 Hz、44.792 Hz相近。通过轴承拆卸和镗孔实验,验证了包络解调分析法在轴承故障辨识的有效性。实验结果表明:NN3048轴承滚动体和NU1038轴承外环磨损是导致切削振纹的故障源,理论方法故障辨识结果与拆卸实验辨识结果一致。

数控车工编程加工工艺设计技巧研究

数控机床加工的精度与效率远超普通车床,合理设计加工工艺,可提升生产零件的质量,赋予其更高价值,促进行业发展。该文分析影响数控车工编程加工质量的因素,明确设计加工工艺原则,结合数控车工编程加工工艺发展需要,探究设计加工工艺的技巧,充分发挥数控车工编程加工工艺优势,保证生产产品的质量。

数控车床加工的产品质量控制

使用数控车床在加工过程中,经常会碰到尺寸精度不稳定、位置精度不稳定、表面粗糙度不稳定等产品质量难以控制的问题,甚至会碰到不明原因的振刀、断刀、缠屑、零件变形等问题,本文主要从三个大方面阐述数控车床加工的产品质量控制方法,数控车床设备,工艺方法、刀杆、刀片的选择和切削用量。