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-NC TeachnologyResearch and development process to such various kinds of new technologies as numerical control lathe , machining center , FMS , CIMS ,etc. of countries all over the world, linked to with the international economic situation closely. The machine tool industry has international economy to mutually promote and develop, enter 21 alert eras of World Affairs, the function that peoples knowledge plays is more outstanding , and the machine tool industry is regarded as the foundation of the manufacturing industry of the machine, its key position and strategic meaning are more obvious. Within 1991-1994 years, the economic recession of the world, expensive FMS, CIMS lowers the temperature, among 1995-2000 years, the international economy increases at a low speed, according to requisition for NC lathe and the world four major international lathes exhibition in order to boost productivity of users of various fields of present world market (EMO , IMTS , JIMTOF , China CIMT of Japan of U.S.A. of Europe), have the analysis of the exhibit, there are the following several points mainly in the technical research of NC lathe in our times: Pay more attention to new technology and innovationWorldwide , are launching the new craft , new material , new structure , new unit , research and development of the new component in a more cost-effective manner, developmental research of for instance new cutter material , the new electric main shaft of main shaft structure , high speed , high-speed straight line electrical machinery ,etc. Regard innovating in improvement of the processing technology as the foundation, for process ultra and hard difficult to cut material and special composite and complicated part , irregular curved surface ,etc. research and develop new lathe variety constantly.Improve the precision and research of machine toolingIn order to improve the machining accuracy of the machining center , are improving rigidity of the lathe , reduction vibration constantly, dispel hotly and out of shape, reduce the noise , improve the precision of localization of NC lathe , repeat precision , working dependability , stability , precision keeping, world a lot of country carry on lathe hot error , lathe sport and load out of shape software of error compensate technical research, take precision compensate , software compensate measure improve , some may make this kind of error dispel 60% already. And is developing retrofit constantly, nanometer is being processed.Improve the research of the machine tooling productivityWorld NC lathe, machining center and corresponding some development of main shaft , electrical machinery of straight line , measuring system , NC system of high speed, under the prerequisite of boosting productivity.What a lot of countries have already begun to the numerical control system melt intelligently, openly, study networkedlyelligent research of the numerical control systemMainly showing in the following aspects: It is intelligent in order to pursue the efficiency of processing and process quality, the self-adaptation to the processing course is controlled, the craft parameter produces research automatically; Join the convenient one in order to improve the performance of urging and use intelligently, to the feedback control , adaptive operation , discerning automatically load selects models automatically , since carries on research whole definitely ,etc. of the electrical machinery parameter; There are such research of the respect as intelligent automatic programming , intelligent man-machine interface , intelligence diagnosing , intelligent monitoring ,etc. The numerical control system melts and studies openMainly showing in the following aspects: The development of the numerical control system is on unified operation platform, face the lathe producer and support finally, through changing, increasing or cutting out the structure target(numerical control target ), form the seriation, and can use users specially conveniently and the technical know-how is integrated in the control system, realize the open numerical control system of different variety , different grade fast, form leading brand products with distinct distinction. System structure norm of the open numerical control system at present, norm , disposing the norm , operation platform , numerical control systematic function storehouse and numerical control systematic function software developing instrument ,etc. are the core of present research to pass through.Meeting the manufacture system of the production line , demand for the information integration of the manufacturing company networkedly greatly of numerical control equipment, it is a basic unit of realizing the new manufacture mode too.Process according to main shaft space position when it classifies to be as follows, horizontal and vertical machining center.Horizontal machining center, refer to the machining center that the axis level of the main shaft is set up . Horizontal machining center for 3-5 sport coordinate axis, a common one three rectilinear motion coordinate axis and one turn the coordinate axis of sports round (turn the workingbench round), it can one is it is it finish other 4 Taxi processing besides installing surfaces and top surfaces to insert to install in work piece, most suitable for processing the case body work piece . Compared with strength type machining center it, the structure is complicated, the floor space is large, quality is large, the price is high.Vertical machining center, the axis of the main shaft of the vertical machining center, in order to set up vertically, its structure is mostly the regular post type, the workingbench is suitable for processing parts for the slippery one of cross, have 3 rectilinear motion coordinate axis generally , can find a room for one horizontal numerical control revolving stage (the 4th axle ) of axle process the spiral part at workingbench. The vertical machining center is of simple structure, the floor space is small, the price is low, after allocating various kinds of enclosures , can carry on the processing of most work pieces .Large-scale gantry machining center, the main shafts are mostly set up vertically, is especially used in the large-scale or with complicated form work piece , is it spend the many coordinate gantry machining center to need like aviation , aerospace industry , some processing of part of large-scale steam turbine.Five machining centers, this kind of machining center has function of the vertical and horizontal machining center, one is it after inserting , can finish all five Taxi processing besides installing the surface to install in work piece, the processing way can make form of work piece error lowest , save 2 times install and insert working, thus improve production efficiency , reduce the process cost.Is it mill machining center to bore, is it mill for vertical door frame machining center , horizontal door frame mill the machining center and Longmen door frame mill the machining center to divide into. Processing technology its rely mainly on the fact that the door frame is milled, used in case body, shell and various kinds of complicated part special curve and large processes , curved surface of outline process, suitable for many varieties to produce in batches small.Complex machining center, point five times and compound and process mainly, the main shaft head can be turned round automatically, stand, lie and process, after the main shaft is turned round automatically, realize knowing that varies in the horizontal and vertical direction. Single workingbench , a pair of workingbench machining center;Single axle , dual axle , three axle can change machining center , main shaft of case;Transfer vertically to the tower machining center and transfer ;One hundred sheets of storehouses adds the main shaft and changes one one hundred sheets of machining centers;One hundred sheets of storehouses connects and writes hands to add the main shaft and change one hundred sheets of machining centers; One hundred sheets of storehouses adds the manipulator and adds one pair of main shafts to transfer to the tower machining center.At present, the advanced manufacturing technology in the world is rising constantly, such application of technology as ultrafast cutting , ultraprecision processing ,etc., the rapid development of the flexible manufacturing system and integrated system of the computer one is constant and ripe, have put forward higher demand to the process technology of numerical control. Nowadays the numerical control lathe is being developed in several following directions.The speed and precision at a high speed , high accuracy are two important indexes of the numerical control lathe , it concerns directly that processes efficiency and product quality. At present, numerical control system adopt-figure number, frequency high processor, in order to raise basic operation speed of system. Meanwhile , adopt the super large-scale integrated circuit and many microprocessors structure, in order to improve systematic data processing ability , namely improve and insert the speed and precision of mending operation. Adopt the straight line motor and urge the straight line of the lathe workingbench to be servo to enter to the way directly, it is quite superior that its responds the characteristic at a high speed and dynamically. Adopt feedforward control technology , make it lag behind error reduce greatly , thus improve the machining accuracy cut in corner not to track.For meet ultrafast demand that process, numerical control lathe adopt main shaft motor and lathe structure form that main shaft unite two into one, realize frequency conversion motor and lathe main shaft integrate , bearing , main shaft of electrical machinery adopt magnetism float the bearing , liquid sound pigeonhole such forms as the bearing or the ceramic rolling bearing ,etc. At present, ceramic cutter and diamond coating cutter have already begun to get application.Multi-functional to is it change all kinds of machining centers of organization (a of capacity of storehouse can up to 100 of the above ) automatically to furnished with, can realize milling paring , boring and pares , bores such many kinds of processes as paring , turning , reaming , reaming , attacking whorl ,etc. to process at the same time on the same lathe , modern numerical control lathe adopt many main shaft , polyhedron cut also , carry on different cutting of way process to one different position of part at the same time. The numerical control system has because adopted many CPU structure and cuts off the control method in grades, can work out part processing and procedure at the same time on a lathe , realize so-called the front desk processes , the backstage supporter is an editor . In order to meet the needs of integrating the systematic one in flexible manufacturing system and computer, numerical control system have remote serial interface , can network , realize data communication , numerical control of lathe, can control many numerical control lathes directly too. Intelligent modern numerical control lathe introduce the adaptive control technology, according to cutting the change of the condition, automatic working parameter, make the processing course can keep the best working state , thus get the higher machining accuracy and roughness of smaller surface , can improve the service life of the cutter and production efficiency of the equipment at the same time . Diagnose by oneself , repair the function by oneself, among the whole working state, the system is diagnosed, checked by oneself to CNC system and various kinds of equipment linking to each other with it at any time. While breaking down , adopt the measure of shutting down etc. immediately , carry on the fault alarm, brief on position , reason to break down ,etc. Can also make trouble module person who take off automatically , put through reserve module , so as to ensure nobody demand of working environment. For realize high trouble diagnose that requires , its development trend adopts the artificial intelligence expert to diagnose the system.Numerical control programming automation with the development of application technology of the computer, CAD/CAM figure interactive automatic programming has already get more application at present, it is a new trend of the technical development of numerical control. It utilize part that CAD draw process pattern , is it calculate the trailing punishing to go on by cutter orbit data of computer and then, thus produce NC part and process the procedure automatically, in order to realize the integration of CAD and CAM. With the development of CIMS technology , the full-automatic programming way in which CAD/CAPP/CAM integrates has appeared again at present, it, and CAD/CAM systematic programming great difference their programming necessary processing technology parameter neednt by artificial to participate in most, get from CAPP database in system directly.The dependability of the dependability maximization numerical control lathe has been the major indicator that users cared about most all the time . The numerical control system will adopt the circuit chip of higher integrated level , will utilize the extensive or super large-scale special-purpose and composite integrated circuit, in order to reduce the quantity of the components and parts , to improve dependability . Through the function software of the hardware, in order to meet various kinds of demands for controlling the function, adopt the module , standardization , universalization and seriation of the structure lathe noumenonn of the hardware at the same time , make not only improve the production lot of the hardware but also easy to is it produce to organize and quality check on. Still through operating and starting many kinds of diagnostic programs of diagnosing , diagnosing , diagnosing off-line online etc. automatically, realize that diagnoses and reports to the police the trouble to hardware , software and various kinds of outside equipment in the system. Utilize the warning suggestion, fix a breakdown in time; Utilize fault-tolerant technology, adopt and design the important part redundantly , in order to realize the trouble resumes by oneself; Utilize various kinds of test , control technology , exceed Cheng , one one hundred sheets of damages , interfering , cutting out ,etc. at the time of various kinds of accidents as production, carry on corresponding protection automatically.Control system miniaturization systematic miniaturization of numerical control benefit and combine the machine , electric device for an organic whole. Adopt the super large-scale integrated component , multi-layer printed circuit board mainly at present, adopt the three-dimensional installation method , make the electronic devices and components must use the high density to install, narrow systematic occupying the space on a larger scale. And utilize the new-type slim display of colored liquid crystal to substitute the traditional cathode ray tube, will make the operating system of numerical control miniaturize further. So can install it on the machine tool conveniently, benefit the operation of the numerical control lathe correctly even more.数控技术世界各国对数控机床、加工中心以至FMS、CIMS等各种新技术的研究与发展进程,是与世界经济形势紧密相连的。机床工业有世界经济相互促进和发展,进入21世界知识机警时代,人们的知识所起的作用更加突出,而机床工业作为机器制造业的基础,其重点地位与战略意义也更加明显。在19911994年间,世界经济衰退,昂贵的FMS,CIMS降温,19952000年间,世界经济在低速增长,根据当前世界市场各方面用户为提高生产率对NC机床的要求以及世界四大国际机床展(欧洲的EMO、美国的IMTS、日本的JIMTOF、中国的CIMT)上展品的分析,当前世界NC机床的技术研究主要有以下几点:在世界范围内,对新工艺、新材料、新结构、新单元、新元件的研究开发工作正在大力开展,如新的刀具材料、新的主轴结构、高速电主轴、高速直线电机等的开发研究。以加工工艺的改进创新为基础,为加工超硬、难切削材料及特殊复合材料及复杂零件、不规则曲面等在不断研究开发新机种。为了提高加工中心的加工精度,不断提高机床的刚度、减少振动,消除热变形,降低噪声,提高NC机床的定位精度、重复精度、工作可靠性、稳定性、精度保持性,世界很多国家都在进行机床热误差、机床运动及负载变形误差的软件补偿技术研究,并采取精度补偿、软件补偿等措施加以改善,有的已经可以使此类误差消除60%。并在不断开发精细加工,纳米加工。世界NC机床、加工中心及相应的高速点主轴、直线电机、测量系统、NC系统的开发,均以提高生产率为前提。主要表现在:为追求加工效率和加工质量的智能化,对加工过程的自适应控制,工艺参数自动生成进行研究;为提高驱动性能及使用连接方便的智能化,对反馈控制、电机参数的自适应运算、自动识别负载自动选定模型、自整定等进行研究;还有智能化的自动编程、智能化的人机界面、智能诊断、智能监控等方面的研究。主要表现在:数控系统的开发在统一的运行平台上,面向机床厂家和最终拥护,通过改变、增加或剪裁结构对象(数控对象),形成系列化,并可方便地将用户的特殊应用和技术诀窍集成到控制系统中,快速实现不同品种、不同档次的开放式数控系统,形成具有鲜明个性的名牌产品。目前开放式数控系统的体系结构规范、通行规范、配置规范、运行平台、数控系统功能库以及数控系统功能软件开发工具等是当前研究的核心。数控装备的网络化将极大地满足生产线制造系统、制造企业对信息集成的需求,也是实现新的制造模式的基础单元。按主轴加工时的空间位置分类有:卧式和立式加工中心。卧式加工中心,是指主轴轴线水平设置的加工中心。卧式加工中心一般具有35个运动坐标轴,常见的是三个直线运动坐标轴和一个回转运动坐标轴(回转工作台),它能在工件一次装夹完成除安装面和顶面以外的其余4个面的加工,最适合加工箱体类工件。它与力式加工中心相比,结构复杂,占地面积大,质量大,价格高。立式加工中心,立式加工中心主轴的轴线为垂直设置,其结构多为固定立柱式,工作台为十字滑台,适合加工盘类零件,一般具有3个直线运动坐标轴,并可在工作台上安置一个水平轴的数控转台(第4轴)来加工螺旋类零件。立式加工中心结构简单,占地面积小,价格低,配备各种附件后,可进行大部分工件的加工。大型龙门式加工中心,主轴多为垂直设置,尤其使用于大型或形状复杂的工件,像航空、航天工业及大型汽轮机上的某些零件的加工都需要用这类多坐标龙门式加工中心。五面加工中心,这种加工中心具有立式和卧式加工中心的功能,在工件一次装夹后,能完成除安装面外的所有五个面的加工,这种加工方式可以使工件的形状误差降到最低,省去二次装夹工作,从而提高生产效率,降低加工成本。镗铣加工中心,分为立式樘铣加工中心、卧式樘铣加工中心和龙门樘铣加工中心。其加工工艺以樘铣为主,用于箱体,壳体以及各种复杂零件特殊曲线和曲面轮廓的多工序加工,适合多品种小批量生产。复合加工中心,主要指五面复合加工,主轴头可自动回转,进行立,卧加工,在主轴自动回转后,在水平和垂直方向实现知道变换。 单工作台、双工作台加工中心; 单轴、双轴、三轴及可换主轴箱的加工中心; 立式转塔加工中心和卧式转塔加工中心; 刀库加主轴换刀加工中心; 刀库接写手加主轴换刀加工中心; 刀库加机械手加双主轴转塔加工中心。目前,世界先进制造技术不断兴起,超高速切削、超精密加工等技术的应用,柔性制造系统的迅速发展和计算机集成系统的不断成熟,对数控加工技术提出了更高的要求。当今数控机床正在朝着以下几个方向发展。高速度、高精度化速度和精度是数控机床的两个重要指标,它直接关系到加工效率和产品质量。目前,数控系统采用位数、频率更高的处理器,以提高系统的基本运算速度。同时,采用超大规模的集成电路和多微处理器结构,以提高系统的数据处理能力,即提高插补运算的速度和精度。并采用直线电动机直接驱动机床工作台的直线伺服进给方式,其高速度和动态响应特性相当优越。采用前馈控制技术,使追踪滞后误差大大减小,从而改善拐角切削的加工精度。为适应超高速加工的要求,数控机床采用主轴电动机与机床主轴合二为一的结构形式,实现了变频电动机与机床主轴一体化,主轴电机的轴承采用磁浮轴承、液体动静压轴承或陶瓷滚动轴承等形式。目前,陶瓷刀具和金刚石涂层刀具已开始得到应用。多功能化配有自动换刀机构(刀库容量可达100把以上)的各类加工中心,能在同一台机床上同时实现铣削、镗削、钻削、车削、铰孔、扩孔、攻螺纹等多种工序加工,现代数控机床还采用了多主轴、多面体切削,即同时对一个零件的不同部位进行不同方式的切削加工。数控系统由于采用了多CPU结构和分级中断控制方式,即可在一台机床上同时进行零件加工和程序编制,实现所谓的“前台加工,后台编辑”。为了适应柔性制造系统和计算机集成系统的要求,数控系统具有远距离串行接口,甚至可以联网,实现数控机床之间的数据通信,也可以直接对多台数控机床进行控制。智能化现代数控机床将引进自适应控制技术,根据切削条件的变化,自动调节工作参数,使加工过程中能保持最佳工作状态,从而得到较高的加工精度和较小的表面粗糙度,同时也能提高刀具的使用寿命和设备的生产效率。具有自诊断、自修复功能,在整个工作状态中,系统随时对CNC系统本身以及与其相连的各种设备进行自诊断、检查。一旦出现故障时,立即采用停机等措施,并进行故障报警,提示发生故障的部位、原因等。还可以自动使故障模块脱机,而接通备用模块,以确保无人化工作环境的要求。为实现更高的故障诊断要求,其发展趋势是采用人工智能专家诊断系统。数控编程自动化随着计算机应用技术的发展,目前CADCAM图形交互式自动编程已得到较多的应用,是数控技术发展的新趋势。它是利用CAD绘制的零件加工图样,再经计算机内的刀具轨迹数据进行计算和后置处理,从而自动生成NC零件加工程序,以实现CAD与CAM的集成。随着CIMS技术的发展,当前又出现了CADCAPPCAM集成的全自动编程方式,它与CADCAM系统编程的最大区别是其编程所需的加工工艺参数不必由人工参与,直接从系统内的CAPP数据库获得。可靠性最大化数控机床的可靠性一直是用户最关心的主要指标。数控系统将采用更高集成度的电路芯片,利用大规模或超大规模的专用及混合式集成电路,以减少元器件的数量,来提高可靠性。通过硬件功能软件化,以适应各种控制功能的要求,同时采用硬件结构机床本体的模块化、标准化和通用化及系列化,使得既提高硬件生产批量,又便于组织生产和质量把关。还通过自动运行启动诊断、在线诊断、离线诊断等多种诊断程序,实现对系统内硬件、软件和各种外部设备进行故障诊断和报警。利用报警提示,及时排除故障;利用容错技术,对重要部件采用“冗余”设计,以实现故障自恢复;利用各种测试、监控技术,当生产超程、刀损、干扰、断电等各种意外时,自动进行相应的保护。控制系统小型化数控系统小型化便于将机、电装置结合为一体。目前主要采用超大规模集成元件、多层印刷电路板,采用三维安装方法,使电子元器件得以高密度安装,较大规模缩小系统的占有空间。而利用新型的彩色液晶薄型显示器替代传统的阴极射线管,将使数控操作系统进一步小型化。这样可以方便地将它安装在机床设备上,更便于对数控机床的操作使用。9
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