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关键词：: C6140 车床数控改造设计 cad图纸

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C6140车床数控改造设计

34页 13000字数+说明书+任务书+外文翻译+8张CAD图纸【详情如下】

A1~横向进给机构示意图.dwg

A1~纵向进给机构示意图.dwg

A1~自动转位刀架.dwg

A2~CA6140数控改造总装图.dwg

A2~LBJ光电编码盘.dwg

A2~数控改造原理图.dwg

A2~脉冲发生器安装示意图.dwg

A3~齿轮零件图.dwg

C6140车床数控改造设计论文.doc

任务书.doc

外文翻译--数控机床.doc

01- 评语.doc

C6140数控机床改造

摘要

　　　由于目前国内的数控机床数量需求量大，达到300万台之巨，要进行全部翻新在实践，物质尚不具有足够的条件，为了达到的条件，为达到较高的精度，实现较好的经济性，对普通车床实行数控开环改造。

　　　了解数控机床的概念，所谓数字控制是按照含有机床(刀具)运动信息程序所指定的顺序自动执行操作的过程。而计算机数控机床就是数控机床在计算机监控下进行工作。它的优点很多,可以在同一机床上一次装夹可完成多个操作，生产率显著提高等优点，但它的价格昂贵。由于我国现在使用的机床大多数为普通车床，自动化程度低,要更新现有机床需要很多资金。为了解决这个问题,也为了适应多品种中、小批量零件加工我们选择机床经济型数控改造。本次设计主要为纵向进给系统的设计，其中包括纵向进给系统改造方案的确定，各零部件的设计。　　

关键词数控；车床；改造；

C6140 ordinary lathe of numerical control technology transformation

Abstract

　　　Due to the current number of domestic CNC machine tool demand to reach300 million units of the giant,to be totally refurbished at the time, the material is not yet sufficient condition,in order to achieve the conditions to achieve high accuracy to achieve better economic nature of the open-loop CNC lathe to implement reform.Understand the concept of CNC machine tools,in accordance with the so-called digital control machine tools(tool)motion information in the order specified by the program automatically performs the operation.CNC machine tool sand CNC machine tools is to work under the supervision of the computer.It has many advantages,can be a fixture on the same machine can perform multiple operations,significantly improve productivity, etc., but it's expensive.Since China is now mostly used lathe machine,low degree of automation, to update existing machines need a lot of money.To solve this problem, but also to adapt to many varieties,small batch machining parts we choose economical CNC machine tools transformation.This design is mainly vertical feed system design, including vertical feed system transformation program to determine various parts of the design.　　　

Keywords　 NC; lathe; transform;

摘要I

AbstractII

第1章绪论1

1.1 课题背景1

1.1.1 国内数控机床现状1

1.1.2 国内数控机床的特点1

1.2 数控机床发展概况2

1.2.1 继续向开放式、基于PC的第六代方向发展2

1.2.2 向高速化和高精度化发展2

1.2.3 向智能化方向发展2

1.3 机床数控化改造的必要性2

1.3.1 微观看改造的必要性2

1.3.2 宏观看改造的必要性3

1.4 数控化改造的市场空间3

1.4.1 国内的市场3

1.4.2 进口设备和生产线的数控化改造市场4

1.5 机床改造的效益分析4

第2章普通车床的数控改造和可行性论证6

2.1 车床的数控改造6

2.1.1 设计内容及任务6

2.1.2 数控机床工作原理及组成6

2.2 可行性论证7

第3章总体方案的拟定和论证8

3.1 总体方案的拟定8

3.2 控制方式类型选择9

3.3 伺服进给机构的改造10

3.3.1 纵向进给机构的改造10

3.3.2 横向进给机构的改造10

3.3.3 步进电动机的选用10

3.3.4 丝杠螺母副10

3.3.5 机床导轨改造10

3.4 总体设计方案的确定11

第4章伺服进给机构设计12

4.1 伺服系统的组成原理12

4.2 伺服进给机构的设计内容和设计计算12

4.2.1 纵向进给系统的设计计算13

4.2.2 横向进给系统的设计计算17

4.3 步进电机的选择20

4.3.1 C6140纵向进给系统步进电机确定20

4.3.2 C6140横向进给系统步进电机的确定20

4.4 伺服系统说明21

4.4.1 机床进给系统的结构及工作原理21

第5章自动转位刀架22

5.1 数控车床刀架的基本要求22

5.2 数控车床刀架结构22

5.3 工作原理23

5.4 刀架的安装24

第6章编码盘的安装部分25

6.1 光电编码器工作原理25

6.2 编码盘的安装25

结论27

致谢28

参考文献29

附录30

绪论

课题背景

　　　1946年诞生了世界上第一台电子计算机，这表明人类创造了可增强和部分代替脑力劳动的工具。它与人类在农业、工业社会中创造的那些只是增强体力劳动的工具相比，起了质的飞跃，为人类进入信息社会奠定了基础。6年后，即在1952年，计算机技术应用到了机床上，在美国诞生了第一台数控机床。从此，传统机床产生了质的变化。近半个世纪以来，数控系统经历了两个阶段和六代的发展。

国内数控机床现状

　　　近年来我国企业的数控机床占有率逐年上升，在大中企业已有较多的使用，在中小企业甚至个体企业中也普遍开始使用。在这些数控机床中，除少量机床以FMS模式集成使用外，大都处于单机运行状态，并且相当部分处于使用效率不高，管理方式落后的状态。?2001年，我国机床工业产值已进入世界第5名，机床消费额在世界排名上升到第3位，达47.39亿美元，仅次于美国的53.67亿美元，消费额比上一年增长25%。但由于国产数控机床不能满足市场的需求，使我国机床的进口额呈逐年上升态势，2001年进口机床跃升至世界第2位，达24.06亿美元，比上年增长27.3%。?近年来我国出口额增幅较大的数控机床有数控车床、数控磨床、数控特种加工机床、数控剪板机、数控成形折弯机、数控压铸机等，普通机床有钻床、锯床、插床、拉床、组合机床、液压压力机、木工机床等。出口的数控机床品种以中低档为主

国内数控机床的特点

新产品开发有了很大突破，技术含量高的产品占据主导地位。

数控机床产量大幅度增长，数控化率显著提高。2001年国内数控金切机床产量已达1.8万台，比上年增长28.5%。金切机床行业产值数控化率从2000年的17.4%提高到2001年的22.7%。

控机床发展的关键配套产品有了突破。微观看改造的必要性

　　　从微观上看，数控机床比传统机床有以下突出的优越性，而且这些优越性均来自数控系统所包含的计算机的威力。

可以加工出传统机床加工不出来的曲线、曲面等复杂的零件。由于计算机有高超的运算能力，可以瞬时准确地计算出每个坐标轴瞬时应该运动的运动量，因此可以复合成复杂的曲线或曲面。

可以实现加工的自动化，而且是柔性自动化，从而效率可比传统机床提高3～7倍。由于计算机有记忆和存储能力，可以将输入的程序记住和存储下来，然后按程序规定的顺序自动去执行，从而实现自动化。数控机床只要更换一个程序，就可实现另一工件加工的自动化，从而使单件和小批生产得以自动化，故被称为实现了"柔性自动化"。

加工零件的精度高，尺寸分散度小，使装配容易不再需要"修配"。

可实现多工序的集中，减少零件在机床间的频繁搬运。

拥有自动报警、自动监控、自动补偿等多种自律功能，因而可实现长时间无人看管加工。

由以上五条派生的好处。

如：降低了工人的劳动强度，节省了劳动力（一个人可以看管多台机床），减少了工装，缩短了新产品试制周期和生产周期，可对市场需求作出快速反应等等。

宏观看改造的必要性

　　　从宏观上看，工业发达国家的军、民机械工业，在70年代末、80年代初已开始大规模应用数控机床。由于采用信息技术对国外军、民机械工业进行深入改造（称之为信息化），最终使得他们的产品在国际军品和民品的市场上竞争力大为增强。而我们在信息技术改造传统产业方面比发达国家约落后20年。如我国机床拥有量中，数控机床的比重（数控化率）到1995年只有1.9％，而日本在1994年已达20.8％，因此每年都有大量机电产品进口。这也就从宏观上说明了机床数控化改造的必要性。

数控化改造的市场空间

　　　机床的数控制化改造是一个方兴未的行业，从各种统计数字上看前途应该是十分光明的，例如："在美国，日本和德国等发达国家，它们的机床改造人作为新的经济增长行业，生意盎然，正处在黄金时代。由于机床以及数控技术的不断进步，机床改造是一个"永恒"的课题。我国的机床改造业，也从老的行业进入到以数控技术为主的新的行业所以不难看出：

国内的市场

　　　我国目前机床总量380余万台，而其中数控机床总数只有11.34万台，即我国机床数控化率不到3％。近10年来，我国数控机床年产量约为0.6～0.8万台，年产值约为18亿元。机床的年产量数控化率为6％。我国机床役龄10年以上的占60％以上；10年以下的机床中，自动/半自动机床不到20％，FMC/FMS等自动化生产线更屈指可数（美国和日本自动和半自动机床占60％以上）。可见我们的大多数制造行业和企业的生产、加工装备绝大数是传统的机床，而且半数以上是役龄在10年以上的旧机床。用这种装备加工出来的产品普遍存在质量差、品种少、档次低、成本高、供货期长，从而在国际、国内市场上缺乏竞争力，直接影响一个企业的产品、市场、效益，影响企业的生存和发展。所以必须大力提高机床的数控化率。

进口设备和生产线的数控化改造市场

　　　我国自改革开放以来，很多企业从国外引进技术、设备和生产线进行技术改造。据不完全统计，从1979～1988年10年间，全国引进技术改造项目就有18446项，大约165.8亿美元。　　这些项目中，大部分项目为我国的经济建设发挥了应有的作用。但是有的引进项目由于种种原因，设备或生产线不能正常运转，甚至瘫痪，使企业的效益受到影响，严重的使企业陷入困境。一些设备、生产线从国外引进以后，有的消化吸收不好，备件不全，维护不当，结果运转不良；有的引进时只注意引进设备、仪器、生产线，忽视软件、工艺、管理等，造成项目不完整，设备潜力不能发挥；有的甚至不能启动运行，没有发挥应有的作用；有的生产线的产品销路很好，但是因为设备故障不能达产达标；有的因为能耗高、产品合格率低而造成亏损；有的已引进较长时间，需要进行技术更新。种种原因使有的设备不仅没有创造财富，反而消耗着财富。　　这些不能使用的设备、生产线是个包袱，也是一批很大的存量资产，修好了就是财富。只要找出主要的技术难点，解决关键技术问题，就可以最小的投资盘活最大的存量资产，争取到最大的经济效益和社会效益。这也是一个极大的改造市场。　　　提高机床数控化效率有两个途径：一是购买新的数控机床；二是对旧的机床进行改造而对于一个机床拥有量大，经济财力又不足的发展中国家来说，采用旧机床改造来提高设备的先进性和数控化率是一个极其有效和使用的途径，采用第二中方法有以下的优点：

减少了投资和交货的期限，同购置新的数控机床相比，一般可以节省60%到80%的费用，改造的费用大大减低。

机械的稳定性可靠机床的床身，立柱等基础件都是重而坚固的铸铁构件，而铸件越久自然失效充分，内应力的消除使得比新的铸件更稳定，这些铸件的使用又可以节约社会资源，又减少了铸铁件生产时对环境的污染。

熟悉了解设备结构性能，便于操作维修购买的新设备，事先很难前面了解机床的结构性能，以至很难预算是否完全适合加工要求，而改造则完全可以避免这种情况，并且大大缩短了对数控机床在使用和维修方面的培训时间，机床一旦改装完成，很快就可以投入使用，见效较快。

可以充分利用现有的条件，可以充分利用现有的地基，不必像购新机时重新构筑新基，同时工夹具、样板和外设备也可以在利用。

可更好的因地制宜合理筛选功能，购买现成的通用型机床，往往对一个具体的生产加工有一些多余的功能，又可能缺少某一个专用的特殊功能，如向机床制造厂提出特殊定货要求，增加某些特殊的加工要求，往往费用大，交货的日期又长。而采用改造的方案就可以根据生产加工要求，采用组合的方法再某些部件设计改造成专用的数控机床。

可及时采用最新技术，充分利用社会资源，由于技术进步和我国机床功能部件专业化生产的发展，目前已有众多的疏忽资源支持机床方面的改造，如随意采购各种尺寸的滚珠丝杠副，且交货期短；采用贴塑导轨新技术，可使传统的滑动导轨的摩擦系数降低五至十几倍来防止爬行，还可以使得刮研极容易，等等例子说明有一大批社会资源，可根据技术更新的发展速度，及时地采用最新技术来提高生产设备的自动化水平和效率，提高设备质量和档次，将旧机场改造成当今水平的机床。普通车床的数控改造和可行性论证

车床的数控改造

设计内容及任务

　　　普通车床（）的数控改造设计内容包括：总体方案的确定和验证、机械改造部分的设计计算（伺服进给机构设计、自动转位刀架的选择或设计、编码盘安装部分的结构设计）、主运动自动变速原理、部分系统控制软件设计。

　　　本设计任务是对卧式车床进行数控化改造，实现微机对车床的数控化控制。利用微机对车床的纵向、横向进给系统进行数字控制，并要达到纵向最小运动单位为0.01/脉冲，横向最小运动单位0.005/脉冲，主运动要实现自动变速，刀架要改造成自动控制的自动转位刀架，要能自动的切削螺纹。

数控机床工作原理及组成

数控机床工作原理：

　　　数控机床加工零件时，首先应编制零件的加工程序，这是数控机床的工作指令。将加工程序输入到数控装置，再由数控装置控制机床主运动的变化、起停，进给运动的方向、速度和位移量以及其它如刀具选择交换、工件夹紧松开和冷却润滑的开、关等动作，使刀具与工件及其它辅助装置严格的按照加工程序规定的顺序、轨迹和参数进行工作，从而加工出符合要求的零件。

数控机床的组成：

　　　数控机床主要由控制介质、数控装置、伺服系统和机床本体等四部分组成，其组成框图如图2-1

图2-1数控机床的组成图

可行性论证

　　　根据《自动化制造系统》，可行性论证使用户建造自动化制造系统项目前所进行的技术和经济性分析报告，是上级主管部门审定和批准立项的基本依据。同样，在进行普通车床的经济型数控改造之前进行合理的、科学的可行性论证是必要的。

　　　根据传统的论证方法，普通车床的经济型数控改造的可行性论证应围绕以下几个方面进行，即企业生产经营现状及存在的问题分析，企业生产经营目标，改造的基础条件、目标、技术方案、投资概算、效益分析，改造后车床的实施计划，结论等。

　　　由于本设计仅作为大学本科生的毕业设计，故在此，设计者仅对改造的投资概算作一简要的可行性论证。

　　　本改造设计是对普通车床C1640进行经济型数控改造。在改造设计中，采用的是广州数控设备厂生产的GSK980T型数控系统，加上两台伺服电机，费用约为4万余元；两套滚珠丝杠副和相配的传动部分以及齿轮副、贴塑导轨等零件，费用约为1万余元，总的改造费用约为5～6万元。旧车床估计截至在6～7万元。这样设备改造费用和旧设备费用总计不会超过13万元。因此，对普通车床作经济型数控改造适合我国国情，是国内企业提高车床的自动化能力和精密程度的有效选择。它具有一定的典型性和实用性。　　　C6140车床主要用于对中小型轴类、盘类以及螺纹零件的加工，这些零件加工工艺要求机床应完成的工作内容有：控制主轴正反转和实现其不同切削速度的主轴变速；刀架能实现纵向和横向的进给运动，并具备在换刀点自动改变四个刀位完成选择刀具；冷却泵、润滑泵的启停；加工螺纹时，应保证主轴转一转，刀架移动一个被加工螺纹的螺距或导程。这些工作内容，就是数控化改造数控系统控制的对象。察看C616车床及有关资料，并且参照数控车床的改造经验，确定总体改造方案。

主传动系统的设计改造

　　　对普通车床进行数控改造时，一般可保留原有的主传动系统和变速操作机构，以减少改造量。但本设计中为了提高车床的自动化程度，以便于在加工过程中实现自动变换切削速度，对其作了相应的简化改造。

　　　采用交流调速电机做车床主轴电机以取代原来的主轴电机，以实现无级调速；并简化原来传动系统，以达到多档调速范围的确定。

数控系统的选择设计

　　　计算机数控装置（CNC）即控制装置是数控机床的中心环节。它通过对加工程序的运行处理，发出控制信号，实现对加工过程的自动控制。

　　　在本设计中，由于时间较短、设计人员少，因而我们决定引进江苏东方数控新技术公司生产的NIM-9702数控系统。

自动转为到家选择设计

　　　数控机床的刀架是机床的重要组成部分。其结构直接影响车床的切削性能和效率。卧式车床数控改造应将原来机床的普通手动转位刀架替换成自动换位刀架，本设计决定采用常州武进数控设备厂生产的LD4四工位螺旋转位刀架。

驱动系统的设计改造

由于改造设计的是简易型经济数控，所以在考虑具体方案时，基本原则是在满足需要的前提下，对于机床尽可能减小改动量，以降低成本。总体改造如下图3-1所示：

参考文献

张新义主编.经济型数控机床系统设计.机械工业出版社,1998:120~125

余英良主编.机床数控改造设计与实例.机械工业出版社,1994:40~47

孙桓等主编.机械原理，高等教育出版社，1995

王贵明主编.数控实用技术，机械工业出版社，2001：12~15

张建纲、胡大锋主编.数控技术.华中科技大学出版社，2000：15~22

张建明主编.机电一体华系统控制．高等教育出版社，2001:135~140

邓星钟主编.机电传动控制．华中科技大学出版社，2001:77~80

王爱玲主编．现代数控机床结构与设计．兵器工业出版，1997:223~280

卜云峰主编．机械工业及自动化简明设计手册上下册．机械工业出版社，1999:200~247

李洪主编．实用机床设计手册．辽宁科学技术出版社，1999:155~173

陶晓杰主编. 伺服电机用于车床进给系统.制造业自动化，2004:20~158

机床设计手册编写组. 机床设计手册（第三册）. 机械工业出版社，1986:65~95

English for Numerical Control Technology.高等教育出版社，2009

John L.Feirer.Machine Tool Metalworking.1973　

A1~横向进给机构示意图.gif

A1~自动转位刀架.gif

A1~纵向进给机构示意图.gif

A2~CA6140数控改造总装图.gif

A2~LBJ光电编码盘.gif

A2~脉冲发生器安装示意图.gif

A2~数控改造原理图.gif

A3~齿轮零件图.gif

内容简介：: 哈尔滨理工大学毕业设计（论文）评语学生姓名：马露学号：0930060101学院：荣成学院专业：机械设计制造及自动化任务起止时间： 2013 年 2月25 日至2013年 6月 21 日毕业设计（论文）题目：C6140车床的数控改造指导教师对毕业设计（论文）的评语：该课题源于生产实践，该同学在毕业设计中，态度端正，能把所学习相关知识运用设计中，设计结构基本合理正确，设计论文论述正确、格式规范，能正确运用所学基本知识，完成任务要求，可以参加答辩。指导教师签名：指导教师职称：评阅教师对毕业设计（论文）的评语：该同学论文格式规范，对机械设计有了一定了解，设计符合任务书要求，所做画纸符合要求，但在图纸的绘制和尺寸的标注需要改进，建议参加答辩。评阅教师签名：评阅教师职称：答辩委员会对毕业设计（论文）的评语：该同学的设计符合“毕业设计任务书”的要求，任务量适中，答辩表述清晰，能恰当的回答论文的有关提问，概念清晰，条理性强，设计的内容合理，掌握了一定的基础知识和基本技能。符合学院本科毕业设计的要求。答辩委员会评定，该生毕业设计（论文）成绩为：答辩委员会主席签名：职称：年月日教务处制表哈尔滨理工大学专科生毕业论文哈尔滨理工大学荣成学院本科生毕业设计（论文）任务书学生姓名：马露学号：0930060101学院：荣成学院专业：机械设计制造及其自动化任务起止时间： 2013年02月25日至 2013年06月 21日毕业设计（论文）题目：C6140车床数控改造毕业设计工作内容：1、实际调研，收集相关资料，完成开题报告；13周。2、结合生产实际，对C6140车床数控改造；3、设计C6140车床数控改造原理图；47周。4、设计C6140车床数控改造纵向、横向进给结构图；811周。5、设计相关零件图； 1213周。6、撰写毕业设计论文。 1416周。注：要求全部用计算机绘图和打印文稿（交打印件和电子稿）资料：1、金属切削机床与数控机床；2、非标设计手册；3、金属切削用量手册；4、相关的技术资料。指导教师意见：签名：2013年 2 月 24 日系主任意见：签名：2013年2月 25日附录外文翻译CNC machine toolsEnterprises still have large amounts general-purpose machine tools which have longevity of service, low precision, can not adapt to mass production, low automatization and adaptability, but can not be washed out because of its low cost and continuity of enterprises production.As a representative production of mechanical, electronic, hydraulic and pneumatic integration, numerically controlled machines have a stabilization quality and high efficiency, and can solve problems such as complex structure, high precision, mass production, part variety in machining.Purchasing new numerically controlled machines is an important way to improve production precision and efficiency, but it may not come true to many enterprises because it cost much. Enterprises equipment updating step are counteracted severly. So General lathes numerically controlled reforming is a quick way that costs less, improve production precision and efficiency, and it can improve enterprises competitive power. So it can takes its place in our way to a powerful manufacturing country. The main contents is:1 The economical efficiency of the reform is evaluated in detail and the reforming scheme is maked according to misty optimums synthesize adjudicate principle.2 The ball screws type, assembling, supporting, bearing type, and stepping motorof feeding system is designed.3 The import and domestic NC systems were compared carefully, brought up a choose method and selected the NC system and automatic tool rest according to the function and accuracy index of reforming.4 The complete electricity control diagram was drawn out according to the result of comparing CA6140s electricity control system and principle with the reforming CJK6140-As NC system.5 In order to protect the function of cutting a screw ,we carefully studied the impulse regulator and its connection with the principal axis, and draw out a techniquediagram.6 Disassembled the lathe, throw away the old feeding system, repaired the main driving system ,covered plastics on sliding surface, shoveling or scraping and testing, counted or measured the parts of the lathe.7 Draw out parts diagrams and assemble diagram.8 Methods of installing and testing of general purpose lathes numerically controlled reforming were put forward. While the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment.The first benefit offered by all forms of CNC machine tools is improved automation. The operator intervention related to producing workpieces can be reduced or eliminated. Many CNC machines can run unattended during their entire machining cycle, freeing the operator to do other tasks. This gives the CNC user several side benefits including reduced operator fatigue, fewer mistakes caused by human error, and consistent and predictable machining time for each workpiece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing workpieces with conventional machine tools.The second major benefit of CNC technology is consistent and accurate workpieces. Todays CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical workpieces can be easily produced with precision and consistency.A third benefit offered by most forms of CNC machine tools is flexibility. Since these machines are run from programs, running a different workpiece is almost as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since these machines are very easy to set up and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with todays just-in-time (JIT) product requirements.Motion control - the heart of CNCThe most basic function of any CNC machine is automatic, precise, and consistent motion control. Rather than applying completely mechanical devices to cause motion as is required on most conventional machine tools, CNC machines allow motion control in a revolutionary manner2. All forms of CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned along their lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed commands. Generally speaking, the motion type (rapid, linear, and circular), the axes to move, the amount of motion and the motion rate (feedrate) are programmable with almost all CNC machine tools.A CNC command executed within the control tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw. And the ball screw drives the linear axis (slide). A feedback device (linear scale) on the slide allows the control to confirm that the commanded number of rotations has taken place3. Refer to fig.1. Fig.1Though a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis.How axis motion is commanded - understanding coordinate systemsIt would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion amount4. (This would be like having to figure out how many turns of the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more logical way by utilizing some form of coordinate system. The two most popular coordinate systems used with CNC machines are the rectangular coordinate system and the polar coordinate system. By far, the more popular of these two is the rectangular coordinate system.The program zero point establishes the point of reference for motion commands in a CNC program. This allows the programmer to specify movements from a common location. If program zero is chosen wisely, usually coordinates needed for the program can be taken directly from the print.With this technique, if the programmer wishes the tool to be sent to a position one inch to the right of the program zero point, X1.0 is commanded. If the programmer wishes the tool to move to a position one inch above the program zero point, Y1.0 is commanded. The control will automatically determine how many times to rotate each axis drive motor and ball screw to make the axis reach the commanded destination point . This lets the programmer command axis motion in a very logical manner. Refer to fig.2, 3. Fig.2 Fig.3All discussions to this point assume that the absolute mode of programming is used6. The most common CNC word used to designate the absolute mode is G90. In the absolute mode, the end points for all motions will be specified from the program zero point. For beginners, this is usually the best and easiest method of specifying end points for motion commands. However, there is another way of specifying end points for axis motion.In the incremental mode (commonly specified by G91), end points for motions are specified from the tools current position, not from program zero. With this method of commanding motion, the programmer must always be asking How far should I move the tool? While there are times when the incremental mode can be very helpful, generally speaking, this is the more cumbersome and difficult method of specifying motion and beginners should concentrate on using the absolute mode.Be careful when making motion commands. Beginners have the tendency to think incrementally. If working in the absolute mode (as beginners should), the programmer should always be asking To what position should the tool be moved? This position is relative to program zero, NOT from the tools current position.Aside from making it very easy to determine the current position for any command, another benefit of working in the absolute mode has to do with mistakes made during motion commands. In the absolute mode, if a motion mistake is made in one command of the program, only one movement will be incorrect. On the other hand, if a mistake is made during incremental movements, all motions from the point of the mistake will also be incorrect.Assigning program zeroKeep in mind that the CNC control must be told the location of the program zero point by one means or another. How this is done varies dramatically from one CNC machine and control to another8. One (older) method is to assign program zero in the program. With this method, the programmer tells the control how far it is from the program zero point to the starting position of the machine. This is commonly done with a G92 (or G50) command at least at the beginning of the program and possibly at the beginning of each tool.Another, newer and better way to assign program zero is through some form of offset. Refer to fig.4. Commonly machining center control manufacturers call offsets used to assign program zero fixture offsets. Turning center manufacturers commonly call offsets used to assign program zero for each tool geometry offsets. Fig. 4 Flexible manufacturing cellsA flexible manufacturing cell (FMC) can be considered as a flexible manufacturing subsystem. The following differences exist between the FMC and the FMS:1 An FMC is not under the direct control of thecentral computer. Instead, instructions from the centralcomputer are passed to the cell controller.2 The cell is limited in the number of part families itcan manufacture.The following elements are normally found in an FMC:1 Cell controller2 Programmable logic controller (PLC)3 More than one machine tool4 A materials handling device (robot or pallet)The FMC executes fixed machining operations with parts flowing sequentially between operations. High speed machiningThe term High Speed Machining (HSM) commonly refers to end milling at high rotational speeds and high surface feeds. For instance, the routing of pockets in aluminum airframe sections with a very high material removal rate1. Over the past 60 years, HSM has been applied to a wide range of metallic and non-metallic workpiece materials, including the production of components with specific surface topography requirements and machining of materials with hardness of 50 HRC and above. With most steel components hardened to approximately 32-42 HRC, machining options currently include: Rough machining and semi-finishing of the material in its soft (annealed) condition heat treatment to achieve the final required hardness = 63 HRC machining of electrodes and Electrical Discharge Machining (EDM) of specific parts of dies and moulds (specifically small radii and deep cavities with limited accessibility for metal cutting tools) finishing and super-finishing of cylindrical/flat/cavity surfaces with appropriate cemented carbide, cermet, solid carbide, mixed ceramic or polycrystalline cubic boron nitride (PCBN)For many components, the production process involves a combination of these options and in the case of dies and moulds it also includes time consuming hand finishing. Consequently, production costs can be high and lead times excessive.It is typical in the die and mould industry to produce one or just a few tools of the same design. The process involves constant changes to the design, and because of these changes there is also a corresponding need for measuring and reverse engineering .The main criteria is the quality level of the die or mould regarding dimensional, geometric and surface accuracy. If the quality level after machining is poor and if it cannot meet the requirements, there will be a varying need of manual finishing work. This work produces satisfactory surface accuracy, but it always has a negative impact on the dimensional and geometric accuracy.One of the main aims for the die and mould industry has been, and still is, to reduce or eliminate the need for manual polishing and thus improve the quality and shorten the production costs and lead times.Main economical and technical factors for the development of HSMSurvivalThe ever increasing competition in the marketplace is continually setting new standards. The demands on time and cost efficiency is getting higher and higher. This has forced the development of new processes and production techniques to take place. HSM provides hope and solutions.MaterialsThe development of new, more difficult to machine materials has underlined the necessity to find new machining solutions. The aerospace industry has its heat resistant and stainless steel alloys. The automotive industry has different bimetal compositions, Compact Graphite Iron and an ever increasing volume of aluminum3. The die and mould industry mainly has to face the problem of machining high hardened tool steels, from roughing to finishing.QualityThe demand for higher component or product quality is the result of ever increasing competition. HSM, if applied correctly, offers a number of solutions in this area. Substitution of manual finishing is one example, which is especially important on dies and moulds or components with a complex 3D geometry.ProcessesThe demands on shorter throughput times via fewer setups and simplified flows (logistics) can in most cases, be solved by HSM. A typical target within the die and mould industry is to completely machine fully hardened small sized tools in one setup. Costly and time consuming EDM processes can also be reduced or eliminated with HSM.Design & developmentOne of the main tools in todays competition is to sell products on the value of novelty. The average product life cycle on cars today is 4 years, computers and accessories 1.5 years, hand phones 3 months. One of the prerequisites of this development of fast design changes and rapid product development time is the HSM technique. Complex productsThere is an increase of multi-functional surfaces on components, such as new design of turbine blades giving new and optimized functions and features. Earlier designs allowed polishing by hand or with robots (manipulators). Turbine blades with new, more sophisticated designs have to be finished via machining and preferably by HSM . There are also more and more examples of thin walled workpieces that have to be machined (medical equipment, electronics, products for defence, computer parts)Production equipmentThe strong development of cutting materials, holding tools, machine tools, controls and especially CAD/CAM features and equipment, has opened possibilities that must be met with new production methods and techniques5.Definition of HSMSalomons theory, Machining with high cutting speeds. on which, in 1931, took out a German patent, assumes that at a certain cutting speed (5-10 times higher than in conventional machining), the chip removal temperature at the cutting edge will start to decrease.Given the conclusion: . seems to give a chance to improve productivity in machining with conventional tools at high cutting speeds.Modern research, unfortunately, has not been able to verify this theory totally. There is a relative decrease of the temperature at the cutting edge that starts at certain cutting speeds for different materials.The decrease is small for steel and cast iron. But larger for aluminum and other non-ferrous metals. The definition of HSM must be based on other factors.Given todays technology, high speed is generally accepted to mean surface speeds between 1 and 10 kilometers per minute or roughly 3 300 to 33 000 feet per minute. Speeds above 10 km/min are in the ultra-high speed category, and are largely the realm of experimental metal cutting. Obviously, the spindle rotations required to achieve these surface cutting speeds are directly related to the diameter of the tools being used. One trend which is very evident today is the use of very large cutter diameters for these applications - and this has important implications for tool design.There are many opinions, many myths and many different ways to define HSM.Maintenance and troubleshootingMaintenance for a horizontal MCThe following is a list of required regular maintenance for a Horizontal Machining Center as shown in fig.5. Listed are the frequency of service, capacities, and type of fluids required. These required specifications must be followed in order to keep your machine in good working order and protect your warranty.fig. 5 DailyTop off coolant level every eight hour shift (especially during heavy TSC usage).Check way lube lubrication tank level.Clean chips from way covers and bottom pan.Clean chips from tool changer.Wipe spindle taper with a clean cloth rag and apply light oil.Weekly1 Check for proper operation of auto drain on filter regulator. On machines with the TSC option, clean the chip basket on the coolant tank.Remove the tank cover and remove any sediment inside the tank. Be careful to disconnect the coolant pump from the controller and POWER OFF the control before working on the coolant tank . Do this monthly for machines without the TSC option.Check air gauge/regulator for 85 psi.For machines with the TSC option, place a dab of grease on the V-flange of tools. Do this monthly for machines without the TSC option.Clean exterior surfaces with mild cleaner. DO NOT use solvents.Check the hydraulic counterbalance pressure according to the machines specifications.Place a dab of grease on the outside edge of the fingers of the tool changer and run through all tools.MonthlyCheck oil level in gearbox. Add oil until oil begins dripping from over flow tube at bottom of sump tank.Clean pads on bottom of pallets.Clean the locating pads on the A-axis and the load station. This requires removing the pallet.2 Inspect way covers for proper operation and lubricate with light oil, if necessary.Six monthsReplace coolant and thoroughly clean the coolant tank.Check all hoses and lubrication lines for cracking.Annually3 Replace the gearbox oil. Drain the oil from the gearbox, and slowly refill it with 2 quarts of Mobil DTE 25 oil.4 Check oil filter and clean out residue at bottom for the lubrication chart.Replace air filter on control box every 2 years.Mineral cutting oils will damage rubber based components throughout the machine.TroubleshootingThis section is intended for use in determining the solution to a known problem. Solutions given are intended to give the individual servicing the CNC a pattern to follow in, first, determining the problems source and, second, solving the problem.Use common senseMany problems are easily overcome by correctly evaluating the situation. All machine operations are composed of a program, tools, and tooling. You must look at all three before blaming one as the fault area. If a bored hole is chattering because of an overextended boring bar, dont expect the machine to correct the fault.Dont suspect machine accuracy if the vise bends the part. Dont claim hole mis-positioning if you dont first center-drill the hole.Find the problem firstMany mechanics tear into things before they understand the problem, hoping that it will appear as they go. We know this from the fact that more than half of all warranty returned parts are in good working order. If the spindle doesnt turn, remember that the spindle is connected to the gear box, which is connected to the spindle motor, which is driven by the spindle drive, which is connected to the I/O BOARD, which is driven by the MOCON, which is driven by the processor. The moral here is dont replace the spindle drive if the belt is broken. Find the problem first; dont just replace the easiest part to get to.Don tinker with the machineThere are hundreds of parameters, wires, switches, etc., that you can change in this machine. Dont start randomly changing parts and parameters. Remember, there is a good chance that if you change something, you will incorrectly install it or break something else in the process6. Consider for a moment changing the processors board. First, you have to download all parameters, remove a dozen connectors, replace the board, reconnect and reload, and if you make one mistake or bend one tiny pin it WONT WORK. You always need to consider the risk of accidentally damaging the machine anytime you work on it. It is cheap insurance to double-check a suspect part before physically changing it. The less work you do on the machine the better. 数控机床虽然各种数控机床的功能和应用各不相同，但它们有着共同的优点。这里是数控设备提供的比较重要的几个优点。各种数控机床的第一个优点是自动化程度提高了。零件制造过程中的人为干预减少或者免除了。整个加工循环中，很多数控机床处于无人照看状态，这使操作员被解放出来，可以干别的工作。数控机床用户得到的几个额外好处是：数控机床减小了操作员的疲劳程度，减少了人为误差，工件加工时间一致而且可预测。由于机床在程序的控制下运行，与操作普通机床的机械师要求的技能水平相比，对数控操作员的技能水平要求（与基本加工实践相关）也降低了。数控技术的第二个优点是工件的一致性好，加工精度高。现在的数控机床宣称的精度以及重复定位精度几乎令人难以置信。这意味着，一旦程序被验证是正确的，可以很容易地加工出2个、10个或1000个相同的零件，而且它们的精度高，一致性好。大多数数控机床的第三个优点是柔性强。由于这些机床在程序的控制下工作，加工不同的工件易如在数控系统中装载一个不同的程序而己。一旦程序验证正确，并且运行一次，下次加工工件的时候，可以很方便地重新调用程序。这又带来另一个好处可以快速切换不同工件的加工。由于这些机床很容易调整并运行，也由于很容易装载加工程序，因此机床的调试时间很短。这是当今准时生产制造模式所要求的。运动控制CNC的核心任何数控机床最基本的功能是具有自动、精确、一致的运动控制。大多数普通机床完全运用机械装置实现其所需的运动，而数控机床是以一种全新的方式控制机床的运动。各种数控设备有两个或多个运动方向，称为轴。这些轴沿着其长度方向精确、自动定位。最常用的两类轴是直线轴（沿直线轨迹）和旋转轴（沿圆形轨迹）。普通机床需通过旋转摇柄和手轮产生运动，而数控机床通过编程指令产生运动。通常，几乎所有的数控机床的运动类型（快速定位、直线插补和圆弧插补）、移动轴、移动距离以及移动速度（进给速度）都是可编程的。数控系统中的CNC指令命令驱动电机旋转某一精确的转数，驱动电机的旋转随即使滚珠丝杠旋转，滚珠丝杠将旋转运动转换成直线轴（滑台）运动。滑台上的反馈装置（直线光栅尺）使数控系统确认指令转数已完成，普通的台虎钳上有着同样的基本直线运动，尽管这是相当原始的类比。旋转虎钳摇柄就是旋转丝杠，丝杠带动虎钳钳口移动。与台虎钳相比，数控机床的直线轴是非常精确的，轴的驱动电机的转数精确控制直线轴的移动距离。轴运动命令的方式-理解坐标对CNC用户来说，为了达到给定的直线移动量而指令各轴驱动电机旋转多少转，从而使坐标轴运动，这种方法是不可行的。（这就好像为了使钳口准确移动1英寸需要计算出台虎钳摇柄的转数！）事实上，所有的数控系统都能通过采用坐标系的形式以一种较为简单而且合理的方式来指令轴的运动。数控机床上使用最广泛的两种坐标系是直角坐标系和极坐标系。目前用得较多的是直角坐标系。编程零点建立数控程序中运动命令的参考点。这使得操作员能从一个公共点开始指定轴运动。如果编程零点选择恰当，程序所需坐标通常可从图纸上直接获得。如果编程员希望刀具移动到编程零点右方1英寸（25.4毫米）的位置，则用这种方法指令X1.0即可。如果编程员希望刀具移动到编程零点上方1英寸的位置，则指令Y1.0。数控系统会自动确定（计算）各轴驱动电机和滚珠丝杠要转动多少转，使坐标轴到达指令的目标位置。这使编程员以非常合理的方式命令轴的运动，参见图2和图3.理解绝对和相对运动至此，所有的讨论都假设采用的是绝对编程方式。用于指定绝对方式的最常用的数控代码是G90。绝对方式下，所有运动终点的指定都是以编程零点为起点。对初学者来说，这通常是最好也是最容易的指定轴运动终点的方法，但还有另外一种指定轴运动终点的方法。增量方式（通常用G91指定）下，运动终点的指定是以刀具的当前位置为起点，而不是编程零点。用这种方法指定轴运动，编程员往往会问“我该将刀具移动多远的距离？”，尽管增量方式多数时候很有用，但一般说来，这种方法指定轴运动较麻烦、困难，初学者应该重点使用绝对方式。指令轴运动时一定要小心。初学者往往以增量方式思考问题。如果工作在绝对方式（初学者应该如此），编程员应始终在问“刀具应该移动到什么位置？”，这个位置是相对于编程零点这个固定位置而言，而不是相对于刀具当前位置。绝对工作方式很容易确定指令当前位置，除此之外，它的另外一个好处涉及轴运动中的错误。绝对方式下，如果程序的一个轴运动指令出错，则只有一个运动是不正确的。而另一方面，如果在增量运动过程中出错，则从出错的那一点起，所有的运动都是不正确的指定编程零点记住必须以某种方式对数控系统指定编程零点的位置。指定编程零点的方式随数控机床和数控系统的不同而很不相同。（较老的）一种方法是在程序中指定编程零点。用这种方法，编程员告诉数控系统从编程零点到机床起始点的距离。通常用G92（或G50)在程序的一开始指定，很可能在各把刀具的开头指定编程零点。另一种较新、更好的指定编程零点的方法是通过偏置的形式。通常，加工中心上用于指定编程零点的偏置被称作夹具偏置，车削中心上用于指定编程零点的偏置被称作刀具几何偏置。柔性制造单元柔性制造单元（FMC）被认为是柔性制造子系统。以下是FMC和FMS之间的区别：FMC不受中央计算机的直接控制，中央计算机发出的指令被传送到单元控制器。FMC能制造的零件族的数目有限。FMC一般由下列部分组成：单元控制器可编程逻辑控制器（PLC）一台以上的机床物流设备（机器人或托盘）FMC按顺序对零件流执行固定的加工操作。高速加工术语“高速加工(HSM)”一般是指在高转速和大进给量下的立铣。例如，以很高的金属切除率对铝合金飞机翼架的凹处进行切削。在过去的60年中，高速加工己经广泛应用于金属与非金属材料，包括有特定表面形状要求的零件生产和硬度高于或等于HRC 50的材料切削

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