圆柱插补在车削中心上的应用

圆柱插补是体现车削中心重要功能的指令之一.以圆柱凸轮的加工为例,对圆柱插补在车削中心上的应用进行了详细分析,将FANUC系统用户手册中较难理解的理论性的阐述应用到实际生产当中,详细比较了两种加工平面状态下的程序编制方法,并进行了编程方法的优化.     

可配置型五坐标B样条插补控制器的研制

针对采用五轴联动数控机床的线性插补功能进行数控加工存在的不足,提出了一种B样条插补控制策略用于五轴联动数控机床以实现复杂曲面零部件的高速高精数控加工。参考开放式、模块化体系结构控制器(OMAC)标准,开发了具有B样条插补功能的五轴联动数控机床运动控制器。该控制器将控制任务按照实时性要求进行划分。人机交互、代码解析及参数映射关系构造等过程离线完成,插补运算、离散逻辑控制及逆运动学变换等过程由实时线程执行,保证了数控系统的硬实时性。为简化NC程序的编制过程,控制器设计为接收工件坐标系下的加工信息。通过开发适应各种形式数控机床的逆运动学变换模块,并将机床参数设计为可用户定制,使得控制器具有良好的通用性。在控制器内部建立NC程序文件中位置曲线和方位曲线间的参数映射关系,使得机床平动轴与转动轴间的运动规划符合实际加工要求,并可保证加工精度。实际加工实验中,在采用B样条插补算法的NC程序量降低为线性插补NC程序量15%倍时,其插补误差为线性插补误差的45%,控制器插补精度为0.68,表明该B样条插补控制器可以满足五坐标数控加工的要求。     

用四心法加工椭圆工件的数值计算

现在绝大部分的中、低档数控机床都不具备椭圆曲线的插补功能。但是,在实际生产过程中常常用这样的数控机床来加工椭圆工件。用这样的数控机床加工椭圆工件的关键就是数值计算。 在不具备椭圆曲线插补功能的数控机床上加工椭圆工件时,一般是根据零件轮廓用直线或圆弧逼近法进行数值计算的,这是因为大部分的数控机床都具有刀具半径补偿功能。但是,在加工精度比较高的工件     

数控车削椭球面通用宏程序的编制与应用

椭球面加工是数控车削中常见的加工内容之一,一般情况下,数控系统只有直线和圆弧插补功能,而无椭圆插补功能。因此,如果要进行椭球面加工,只能采用CAM软件进行自动编程或宏程序进行手工编程,两者相比,使用宏程序进行编程加工要比自动编程加工更加快捷、灵活。本文以FANUC0i数控系统为例,探讨了数控车削椭球面通用宏程序编制的方法,给出了椭球面加工通用宏程序,并针对凸椭球面和凹椭球面进行了实际加工应用。     

曲线的三参数路径规划车削插补算法研究

为了保证数控加工中复杂曲线零件的车削加工精度,在普通二参数车削加工的基础上,提出了一种三参数路径规划车削插补算法。该算法将复杂曲面数控加工插补过程的路径规划分解为若干插补点之间的最优路径搜索和选取问题,根据不同加工要求设置决策变量,并进行取值判别,通过3个参数联动对曲线进行插补运算,优化加工过程中刀具的路径,并应用于相关的实例分析。研究结果表明,该优化算法能保证加工曲线的光滑性,有利于提高曲线的加工质量,并且该算法还具有计算规模小、求解迅速、数控加工插补误差小等优点。     

DDA法抛物线插补运算研究

数控机床中刀具对工件轮廓的插补运算是数控机床的核心内容,插补运算方法的优劣直接影响机床的加工精度。就目前数控机床的发展情况来看,插补运算的种类繁多,且具有不同的优缺点。对于高精度的数控机床,选取好的插补运算方法是实现多坐标轴联动对复杂曲线(如抛物线)快速插补、提高生产效率的关键。针对以上问题,提出了一种插补运算方法——DDA法。利用该法对复杂曲线即抛物线加工的函数进行运算分析及插补结构框图的构建,推出抛物线不同开口方向、不同插补路线的坐标修正方案,给出各坐标轴插补进给方向,并通过实例分析验证该方法的可行性,为抛物线加工的进一步研究及应用提供理论依据。     

数控车削中心C轴编程探讨

CTX400E是德国(德马吉公司)生产的集车、铣功能于一体的数控机床,其转塔刀架上有能使刀具旋转的动力刀座,主轴具有按轮廓成形要求连续回转(不等速回转)运动和进行连续精确分度的C轴功能,并能与X轴或Z轴联动,交叉构成三锥空间,可进行端面和圆周上任意部位的钻削,铣削和功螺纹加工,在具有插补功能的条件下,还可以实现各种曲面铣削加工,独具特色的C轴铣功能,使零件车削、铣削部位一刀加工完成。对CTX400数控车削中心的功能和数控系统进行了简略描述,并结合一个加工实例详细介绍数控车削中心CTX400E独具特色的强大的C轴编程功能,从而进行C轴编程方法分析及实际应用的探讨。     

数控机床三维空间几何误差补偿方法

为了提高数控机床的加工精度,在系统分析数控机床几何误差常用补偿方法基础上,提出了基于数控系统插补数据的几何误差补偿方法,并将误差补偿功能集成于国产数控系统中,以提高国产数控系统的综合性能。通过实验与仿真结果表明,数控系统插补数据的几何误差补偿方案能显著提高数控机床的加工精度。     

数控车床刀尖半径调整方法

在数控曲面车削加工中,影响曲面精度的主要有机床精度（定位精度、重复定位精度、主轴跳动等）、机床数控系统精度、刀具的制造和安装精度等因素。现代数控机床的精度和控制系统精度已达到微米和亚微米级,完全能满足微米级精密加工的要求。由于数控车床在加工曲面采用的是插补方法（直线插补G01,圆弧插补G02、G03）,刀具刀补值的正确与否直接影响着曲面的加工精度。     

极坐标插补法在车削中心上加工端面轮廓零件的方法

极坐标插补方法是利用数控车削中心加工端面轮廓零件的关键技术。本文以FANUC0i-TC数控车削中心HTC2050z为例,研究了极坐标插补及其编程的要点、车削中心常用的M指令及操作要求,并以极坐标插补法进行了端面轮廓零件的编程,实现了在FANUC0i-TC数控车削中心HTC2050z上加工端面轮廓零件。     

锥面砂轮数控磨齿机运动控制系统电气参数设计研究

在分析锥面砂轮数控磨齿机工作原理、结构及特点的基础上,系统地建立了锥面砂轮数控磨齿机运动控制系统重要电气参数的设计方法,分析了运动速度与电动机功率的定量关系,给出了一个锥面砂轮数控磨齿机运动控制系统电气参数的设计实例。该方法能够对锥面砂轮数控磨齿机电气参数进行更为准确合理的设计,提高系统的经济性,并能推广应用于一般数控机床运动运动控制系统电气参数的设计。     

改善数控机床精度的方法探索与分析

从数控机床的精度指标及检验依据分析入手,介绍了精度补偿、数控系统伺服调整与优化、利用数控系统设置的控制功能及改进机床功能部件设计方案等工程实践方法,旨在改善在用机床或机床精度试验中的精度指标。这些实践方法对数控机床的检验、检测、调试、改造等能提供指导,并行之有效。     

Diagnosing the cause of operational faults in machine tools with an open architecture CNC

The conventional computerized numerical controller (CNC) of machine tools has been increasingly replaced by a PC-based open architecture CNC (OAC) that is independent of a CNC vendor. The OAC and machine tools with an OAC have led to a convenient environment in which user-defined applications can be efficiently implemented within a CNC. This paper proposes a method of diagnosing the cause of operational faults. The method is based on the status of a programmable logic controller in machine tools with an OAC. An operational fault is defined as a disability that occurs during the normal operation of machine tools. Operational faults constitute more than 70 percent of all faults and are also unpredictable because most of them occur without any warning. To quickly and correctly diagnose the cause of an operational fault, two diagnostic models are proposed: the switching function and the step switching function. The cause of the fault is logically diagnosed through a fault diagnosis system using diagnostic models. A suitable interface environment between a CNC and developed application modules is constructed to implement the diagnostic functions in the CNC domain. The results of the diagnosis were displayed on a CNC monitor for machine operators and transmitted to a remote site through a Web browser. The proposed diagnostic method and its results were useful to unskilled machine operators and reduced the machine downtime.     

浅谈数控车床实训教学中的撞刀现象及对策

数控机床的应用越来越广泛,因此,对数控机床的保护不容忽视.撞刀现象会影响数控机床的精确度,为了防止学生在数控车床实训时发生撞刀现象,从程序编制和数控车床操作等方面总结出以下几种常见的撞刀现象与解决方法.     

基于高速数控外圆磨床砂轮架伺服进给系统研究

结合当今数控外圆磨床的发展,采用传递函数的建模方法,结合现代机床动力学原理,对MKS1320高速数控外圆磨床的砂轮架伺服进给系统进行了详细的分析;提出了全闭环数控伺服进给系统中各控制环节的影响程度以及解决手段。     

高速数控机床在机械加工中的应用分析

伴随机械制造行业的深入发展,机械自动化技术在飞速进步,这在一定程度上提高机械加工的速度和质量。为了能够更好地提高数控机床的加工速度,高速数控机床应运而生,通过该技术能够更好地提高数控机床的工作速度,有利于提高产品品质。本文首先针对高速数控机床的概念、原理和特点进行阐述,然后对高速数控机床的分类进行论述,并且对数控机床的工艺以及高速数控机床的应用进行整体分析。     

国内重型数控机床的现状及发展趋势

重型数控机床是能源、交通等行业超重、超大零部件的工作母机，制约着这些行业的发展。结合国内重型数控机床设计与制造的挑战，以数控七轴五联动螺旋桨加工重型车铣复合机床CKX5680为例，介绍了重型数控机床的技术突破与创新；介绍了已投入使用的多型国产重型数控机床及其使用中遇到的问题；对重型数控机床的发展趋势进行了展望。     

Quantitative evaluation method for machining accuracy retention of CNC machine tools considering degenerate trajectory fluctuation

Accuracy retention is an important performance index of CNC machine tools. At present, research on the evaluation of machining accuracy retention of CNC machine tools mainly focuses on accuracy value of a fixed time point or different time periods, but studies on the fluctuation degree of degradation trajectory related to time change are limited. Extracting simple and effective degradation characteristics of machining accuracy and then evaluating machining accuracy retention considering fluctuation of degradation trajectory are necessary. The volume error model of CNC machine tools is established on the basis of multibody system theory in this study. Three-dimensional volume error vector is transformed into one-dimensional machining accuracy degradation by calculating offset distance between spatial error and origin points. Degradation data obtained via regular measurement and calculation are used to establish the complete degradation trajectory model of the CNC machine tools machining accuracy using radial basis function interpolation method according to the fluctuation degree of degradation trajectory, and concepts of average degradation rate and average degradation amount are defined. Lastly, examples showed that these two indicators can intuitively reflect fluctuation degree of machining accuracy degradation of CNC machine tools and effectively and quantitatively evaluate accuracy retention of CNC machine tools. The quantitative evaluation method of accuracy retention of CNC machine tools defined in this study considers the fluctuation degree of accuracy degradation trajectory. The quantitative evaluation index of accuracy retention demonstrates satisfactory engineering application because it can reflect not only the accuracy change of a single machine tool but also accurately compare the accuracy retention between different machine tools.

     

数控机床的发展趋势及国内发展现状

简要分析了数控机床高速化、高精化、复合化、智能化、开放化、并联驱动化、网络化、极端化、绿色化等发展趋势,并指出了我国数控机床发展中存在的问题。     

A novel error compensation implementing strategy and realizing on Siemens 840D CNC systems

Error compensation implementing strategy of CNC machine tools is a key technique. Basing on handwheel offset function of CNC system, a novel error compensation implementing strategy were proposed, and an error compensator is developed to realize the error compensation implementing on machine tools with Siemens 840D CNC systems, which communicates with CNC system by the DRF offset function and substitutes for electronic handwheel of CNC system. The error compensator’s hardware and software systems, in which multithread technique was used to parallel run to avoid CPU’s long-playing employment by one task, were developed. Finally, to test the feasibility of the implementing strategy, an experiment was carried out to compensate geometric error of a heavy-duty CNC floor-typed boring and milling machine tool. Experimental results show that error synthetic compensation equipment developed in this paper can perfectly implement error compensation function.