力明学院大专毕业论文数控车床的基本应用第1页共20页专科力明学院毕业论文题目数控车床的基本应用学生姓名:夏云飞指导教师:解清华专业名称:数控技术所在学院:山东力明科技职业学院摘要世界制造业转移,中国正在逐步成为世界加工厂。美国、德国、韩国等国家已经进入工业化发展的高技术密集时代与微电子时代,钢铁、机械、化工等重工业正逐渐向发展中国家转移。我国目前经济发展已经过了发展初期,正处于重化工业发展中期。未来10年将是中国机械行业发展最佳时期。美国、德国的重化工业发展期延续了18年以上,美国、德国、韩国四国重化工业发展期平均延续了12年,我们估计中国的重化工业发力明学院大专毕业论文数控车床的基本应用第2页共20页展期将至少延续10年,直到2015年。因此,在未来10年中,随着中国重化工业进程的推进,中国企业规模、产品技术、质量等都将得到大幅提升,国产机械产品国际竞争力增强,逐步替代进口,并加速出口。目前,机械行业中部分子行业如船舶、铁路、集装箱及集装箱起重机制造等已经受益于国际间的产业转移,并将持续受益;电站设备、工程机械、床等将受益于产业转移,加快出口进程关键词:数控,工业化发展,刀具,机床目录第一章数控机床的产生第二章数控机床的发展2.1数控系统的发展································································12.2机床的发展趋势································································2第三章数控机床的分类3.1按加工工艺方法分类···························································43.1.1金属切削类数控机床············································································43.1.2特种加工类数控机床············································································43.1.3板材加工类数控机床············································································43.2按控制运动轨迹分类···························································53.1.2点位控制数控机床················································································53.2.2直线控制数控机床················································································53.2.3轮廓控制数控机床················································································53.3按驱动装置的特点分类························································63.3.1开环控制数控机床················································································63.3.2闭环控制数控机床················································································73.3.3半闭环控制数控机床············································································73.3.4混合控制数控机床················································································7第四章数控车的工艺与工装削4.1合理选择切削用量·····························································94.2合理选择刀具··································································94.3合理选择夹具··································································104.4确定加工路线··································································104.5加工路线与加工余量的联系··················································104.6夹具安装要点··································································10力明学院大专毕业论文数控车床的基本应用第3页共20页第五章程序首句妙用与控制尺寸精度的技巧5.1程序首句妙用G00的技巧······················································115.2控制尺寸精度的技巧···························································125.2.1修改刀补值保证尺寸精度······································································125.2.2半精加工消除丝杆间隙影响保证尺寸精度·············································125.2.3程序编制保证尺寸精度·········································································125.2.4修改程序和刀补控制尺寸······································································13第六章数控技术6.1数控机床电气控制系统综述···················································146.2数控机床运动坐标的电气控制················································16结语致谢参考文献力明学院大专毕业论文数控车床的基本应用第4页共20页第一章数控机床的产生在机械制造工业中并不是所有的产品零件都具有很大的批量,单件与小批量生产的零件(批量在10~100件)约占机械加工总量的80%以上。尤其是在造船、航天、航空、机床、重型机械以及国防工业更是如此。为了满足多品种,小批量的自动化生产,迫切需要一种灵活的,通用的,能够适用产品频繁变化的柔性自动化机床。数控机床就是在这样的背景下诞生与发展起来的。它为单件、小批量生产的精密复杂零件提供了自动化的加工手段。根据国家标准GB/T8129-1997,对机床数字控制的定义:用数字控制的装置(简称数控装置),在运行过程中,不断地引入数字数据,从而对某一生产过程实现自动控制,叫数字控制,简称数控。用计算机控制加工功能,称计算机数控(computerizednumerical,缩写CNC)。数控机床即使采用了数控技术的机床,或者说装备了数控系统的机床。从应用来说,数控机床就是将加工过程所需的各种操作(如主轴变速、松加工件、进刀与退刀、开车与停车、选择刀具、供给切削液等)和步骤,以及刀具与工件之间的相对位移量都用数字化的代码来表示,通过控制介质将数字信息送入专用的或通用的计算机,计算机对输入的信息进行处理与运算,发出各种指令来控制机床的伺服系统或其他执行元件,是机床自动加工出所需要的零件。力明学院大专毕业论文数控车床的基本应用第5页共20页第二章数控机床的发展2.1数控系统的发展从1952年第一台数控机床问世后,数控系统已经先后经历了两个阶段和六代的发展,其六代是指电子管、晶体管、集成电路、小型计算机、微处理器和基于工控PC机的通用CNC系统。其中前三代为第一阶段,称作为硬件连接数控,简称NC系统;后三代为第二阶段,乘坐计算机软件数控,简称CNC系统。2.2机床的发展趋势数控机床总的发展趋势是工序集中、高速、高效、高精度以及方便使用、提高可靠性等。(1)工序集中20世纪50年代末期,在一般数控机床的基础上开发了数控加工中心,即自备刀具库的自动换刀数控机床。在加工中心机床上,工件一次装夹后,机床的机械手可以自动更换刀具,连续的对工件进行多种工序加工。目前,加工中心机床的刀具库容量可达到100多把刀具,自动换刀装置的换刀时间仅需0.5~2秒。加工中心机床使工序集中在一台机床上完成,减少了由于工序分散,工件多次安装引起的定位误差,提高了加工精度,同时也减少了机床的台数与占地面积,压缩了半成品的库存量,减少了工序间的辅助时间,有效的提高了数控机床的生产效率和数控加工的经济效益。(2)高速、高效、高精度高速、高效、高精度是机械加工的目标,数控机床因其价格昂贵,在上述三方面的发展也就更为突出。(3)方便使用数控机床制造厂把建立友好的人机界面、提高数控机床的可靠性作为提高竞争能力的主要方面。1)加工编程方便手工编程和自动编程已经使用了几十年,有了长足的发展,在手工编程方面,开发了多种加工循环、参数编程和除直线、圆弧以外的各种插补功能,CAD/CAM的研究发展,从技术上来讲可以替代手工编程。但是一套适用的CAD/CAM软件加上计算机硬件,投资较大,学习、掌握时间较长,对大多数的简单工件很不经济。近年来,发展起来的图形交互式编程系统(WOP,又称面向车间编程),很受用户欢迎。这力明学院大专毕业论文数控车床的基本应用第6页共20页种编程方式不使用G、M代码,而是借助图形菜单,输入整个图形块以及相应参数作为加工指令,形成加工程序,与传统加工时的思维方式类似。图形交互编程方法在制定标准后,有可能成为各种型号的数控机床统一的编程方法。2)使用方法数控机床普遍采用彩色CRT进行人机对话、图形显示和图形模拟的。有的数控机床将采用说明书、编程指南、润滑指南等存入系统共使用者调阅。第三章数控机床的分类3.1按加工工艺方法分类3.1.1.金属切削类数控机床与传统的车、铣、钻、磨、齿轮加工相对应的数控机床有数控车床、数控铣床、数控钻床、数控磨床、数控齿轮加工机床等。尽管这些数控机床在加工工艺方法上存在很大差别,具体的控制方式也各不相同,但机床的动作和运动都是数字化控制的,具有较高的生产率和自动化程度。在普通数控机床加装一个刀库和换刀装置就成为数控加工中心机床。加工中心机床进一步提高了普通数控机床的自动化程度和生产效率。例如铣、镗、钻加工中心,它是在数控铣床基础上增加了一个容量较大的刀库和自动换刀装置形成的,工件一次装夹后,可以对箱体零件的四面甚至五面大部分加工工序进行铣、镗、钻、扩、铰以及攻螺纹等多工序加工,特别适合箱体类零件的加工。加工中心机床可以有效地避免由于工件多次安装造成的定位误差,减少了机床的台数和占地面积,缩短了辅助时间,大大提高了生产效率和加工质量。3.1.2.特种加工类数控机床除了切削加工数控机床以外,数控技术也大量用于数控电火花线切割机床、数控电火花成型机床、数控等离子弧切割机床、数控火