专业英语封面

1、专业英语封面机电工程系Special English专业英语学号（number）_ 080711225 _姓名(name) _孙聪_ 专业(professional) 自动化班级(class)数控2 成绩(grade)_审阅教师(teacher)_佘勃_现代制造技术在内容上包括了金属切削过程及其基本规律、机床、刀具、夹具的基本知识、机械加工和装配工艺规程的设计、机械加工中精度及表面质量的概念及其控制方法、制造技术哲理与现代生产管理模式、制造技术发展的前沿与趋势。形成以机械制造技术应用能力培养为主线的新的课程体系。本课程以机械产品的加工原理、制造方法及所用的设备和工艺装备为主要研究对象，探讨在各

2、种生产条件下，如何以最低成本，较高的劳动生产率生产出优质的产品。零件的加工是在由机床、夹具、刀具、工件所组成的工艺系统完成的，加工质量、成本、效率在很大程度上取决于加工方法及由此而选用的机床、夹具和刀具。过去，机制专业独立设置了几门专业课，以课程群的组合来建立学生的机械制造技术知识结构。由于各门课程自成体系，不仅相关内容低起点的重复多，浪费了大量学时，而且各门课程的知识很难融会贯通、综合运用，不利于机械制造技术应用能力的培养。本课程在内容体系的安排上，通过外圆、内圆、平面、齿形面等典型面的加工，将工艺、机床、夹具、刀具有机地结合在一起，从而加强了针对性和实用性，较好地解决了这一问题。机械制造工

3、业为人类的生存、生产、生活提供各种设备，是国民经济中极其重要的基础产业。所谓四个现代化，从某种意义上说，就是用现代化设备去装备工业、农业、国防和科学技术事业，使之达到先进的水平。制造业为人类创造着辉煌的物质文明。据统计，90年20个工业化国家制造业所创造的财富占国民生产总值（GDP）的比例平均为22.15%，制造业是一个国家的立国之本。制造技术支持着制造业的健康发展，先进的制造技术使一个国家的制造业乃至国民经济处于有竞争力的地位。忽视制造技术的发展，就会导致经济发展走入岐途。机械工业对提高人民生活质量，推动科学技术进步起着十分重要的作用。而机械工业的发展和进步，在很大程度上又取决于机械制造技术

4、的发展。从历史上看，1769年瓦特发明了蒸汽机，但当时加工技术十分落后，苦于加工不出高精度的汽缸而得不到推广应用。1775年，威尔逊成功地改造了一台汽缸镗床，解决了这一难题。就在第二年(1776年)蒸汽机便得到了实际应用，迎来了第一次产业革命，由此可见，机械制造技术的发展对人类科学技术的进步有何等重要的作用。在科学技术高度发展的今天，依然是如此，现代工业对机械制造技术提出了越来越高的要求，如要求达到纳米级(106mm)的超精密加工，大规模集成电路硅片划片的超微细加工，重型设备超大型件的加工，难加工材料和具有特殊物理性能材料的加工等等，诸如此类，给现代机械制造技术提出了许多新的课题。同时，当产品

5、的设计图样决定之后，要提高产品质量和劳动生产率，降低成本，采用先进的制造技术是关键。因此，在未来的竞争中，谁掌握先进的制造技术，谁就拥有控制市场的主动权。另一方面，也正是由于科学技术的发展，又为机械制造技术的发展提供了工具和手段，特别是计算机技术的发展，促使常规技术与精密检测技术和数控技术、传感技术等相互结合，给机械制造领域带来许多新技术、新观念，使产品质量和生产效率大大提高，当前，机械制造技术的发展主要表现在以下几方面：向高柔性化和自动化方向发展。随着国际市场竞争越来越激烈，机电产品的更新周期越来越短，多品种的中小批生产将成为今后生产一种主要类型。如何解决中小批生产的自动化问题是摆在我们面前

6、的一个突出问题。因此，以解决中小批生产自动化为主要目标的柔性制造技术越来越受到重视，如CNC(计算机数控)、CAD/CAM( Computer-Aided Design 、Computer -Aided Manufacturing计算机辅助设计/计算机辅助制造)、FMS(Flexible Manufacturing System柔性制造系统)的应用越来越广泛，一些发达国家，进而正在大力发展CIMS( Computer Integrated Manufacturing System计算机集成制造系统)，使整个生产过程在计算机控制下，不仅实现自动化，而且实现柔性化、智能化、集成化，使产品质量和生产

7、效率大大提高，生产周期缩短，产生了很好的经济效益。精密加工和超精密加工是机械制造技术发展的另一个方面。在现代高科技领域中，产品的精度要求越来越高，有的尖端产品其加工精度达到0.001um，表面粗糙度小于Ra0.005 um，即纳米(nm)级，促使加工精度由微米级(形状尺寸精度0.11um，表面粗糙度为Ra0.030.3 um)向亚微米级和纳米级发展。掌握超精密加工技术，在未来的科技竞争中具有重要意义，也是一个国家制造水平的重要标志。要实现精密和超精密加工，必须具有与之相适应的加工设备、工具、仪器以及加工环境与检测技术。发展高速切削、强力切削，提高切削加工效率也是机械技术发展的一种趋势。而要实现

8、高速切削（切削速度为常用切削速度的510倍）与强力切削关键是要具有与之相适应的机床和切削工具。目前数控车床主轴转速已达5000r/min，国外有的加工中心主轴转速已达20210r/min以上，磨削速度普遍已达4060m/s （一般在35m/s左右），高的已达80120m/s。解放前，我国的机械工业十分落后，几乎没有什么像样的机械工业，解放后经过40多年的建设，我国的机械工业得到了很大的发展，取得了长足的进步，现已建成100多个行业的机械制造工业体系，国民经济各部门的机电设备，已基本上能自行设计制造。但与世界发达国家相比，还有很大差距。我国机床数控化率到1993年仅为3.74%，而世界发达国家已

9、达70%以上。产品更新换代的周期长、质量差、劳动生产率低，经济效益差是机械行业普遍存在的问题。其中落后的机械制造技术水平是造成上述问题的主要原因之一。机床在加工过程中还需要一系列辅助运动，以实现机床的各种辅助动作，为表面成形创造条件，它的种类很多，一般包括：(1)切入运动刀具相对工件切人一定深度，以保证工件达到要求的尺寸。(2)分度运动多工位工作台、刀架等的周期转位或移位，多头螺纹的车削等。(3)调位运动加工开始前机床有关部件的移位，以调整刀具和工件之间的正确相对位置。(4)各种空行程运动切削前后刀具或工件的快速趋近和退回运动，开车、停车、变速、变向等控制运动，装卸、夹紧、松开工件的运动等。（

10、1）带状切屑它的内表面是光滑的，外表面呈毛茸状。加工塑性金属时，在切削厚度较小、切削速度较高、刀具前角较大的工况条件下常形成此类切屑。（2）节状切屑又称挤裂切屑。它的外表面呈锯齿形，内表面有时有裂纹。在切削速度较低、切削厚度较大、刀具前角较小时常产生此类切屑。（3）粒状切屑又称单元切屑。在切屑形成过程中，如剪切面上的剪切应力超过了材料的断裂强度，切屑单元从被切材料上脱落，形成粒状切屑。（4）崩碎切屑加工脆性材料，切削厚度越大越易得到这类切屑。前三种切屑是加工塑性金属时常见的切屑类型。形成带状切屑时，切削过程最平稳，切削力波动小，已加工表面粗糙度较小；形成粒状切屑时切削过程中的切削力波动最大。前

11、三种切屑类型可以随切削条件变化而相互转化，例如，在形成节状切屑工况条件下，如进一步减小前角、降低切削速度或加大切削厚度，就有可能得到粒状切屑；反之，加大前角、提高切削速度或减小切削厚度，就可得到带状切屑。刀具正常磨损的形式有以下几种：1.前刀面磨损2.后刀面磨损3.边界磨损(前、后刀面同时磨损)从对温度的依赖程度来看，刀具正常磨损的原因主要是机械磨损和热、化学磨损。机械磨损是由工件材料中硬质点的刻划作用引起的，热、化学磨损则是由粘结（刀具与工件材料接触到原子间距离时产生的结合现象）、扩散（刀具与工件两摩擦面的化学元素互相向对方扩散、腐蚀)等引起的。(1)磨粒磨损在切削过程中，刀具上经常被一些硬

12、质点刻出深浅不一的沟痕。磨粒磨损对高速钢作用较明显。(2)粘结磨损刀具与工件材料接触到原子间距离时产生的结合现象，称粘结。粘结磨损就是由于接触面滑动在粘结处产生剪切破坏造成。低、中速切削时，粘结磨损是硬质合金刀具的主要磨损原因。(3)扩散磨损切削时在高温作用下，接触面间分子活动能量大，造成了合金元素相互扩散置换，使刀具材料机械性能降低，若再经摩擦作用，刀具容易被磨损。扩散磨损是一种化学性质的磨损。(4)相变磨损当刀具上最高温度超过材料相便温度时，刀具表面金相组织发生变化。如马氏体组织转变为奥氏体，使硬度下降，磨损加剧。因此，工具钢刀具在高温时均用此类磨损。(5)氧化磨损氧化磨损是一种化学性质的

13、磨损。刀具磨损是由机械摩擦和热效应两方面因素作用造成的。1）在低、中速范围内磨粒磨损和粘结磨损是刀具磨损的主要原因。通常拉削、铰孔和攻丝加工时的刀具磨损主要属于这类磨损。2）在中等以上切削速度加工时，热效应使高速钢刀具产生相变磨损、使硬质合金刀具产生粘结、扩散和氧化磨损。二、刀具磨损过程随着切削时间的延长，刀具磨损增加。根据切削实验，可得图示的刀具正常磨损过程的典型磨损曲线。该图分别以切削时间和后刀面磨损量VB（或前刀面月牙洼磨损深度KT）为横坐标与纵坐标。从图可知，刀具磨损过程可分为三个阶段：A.初期磨损阶段B.正常磨损阶段C.急剧磨损阶段2、刀具磨钝标准刀具磨损到一定限度就不能继续使用。这

14、个磨损限度称为磨钝标准。规定后刀面上均匀磨损区的高度VB值作为刀具的磨钝标准。3、刀具的耐用度（刀具寿命）一把新刀（或重新刃磨过的刀具）从开始切削至磨损量达到磨钝标准为止所经历的实际切削时间，称为刀具的耐用度，用T分钟表示。又称为刀具寿命。三、刀具的破损刀具破损和刀具磨损一样，也是刀具失效的一种形式。刀具在一定的切削条件下使用时，如果它经受不住强大的应力（切削力或热应力），就可能发生突然损坏，使刀具提前失去切削能力，这种情况就称为刀具破损。破损是相对于磨损而言的。从某种意义上讲，破损可认为是一种非正常的磨损。刀具的破损有早期和后期（加工到一定的时间后的破损）两种。刀具破损的形式分脆性破损和塑性

15、破损两种。硬质合金和陶瓷刀具在切削时，在机械和热冲击作用下，经常发生脆性破损。脆性破损又分为：1.崩刀2.碎断3.剥落4.裂纹破损。四、刀具寿命(刀具耐用度)的选择原则切削用量与刀具寿命有密切关系。在制定切削用量时，应首先选择合理的刀具寿命，而合理的刀具寿命则应根据优化的目标而定。一般分最高生产率刀具寿命和最低成本刀具寿命两种，前者根据单件工时最少的目标确定，后者根据工序成本最低的目标确定。1粗车车削加工是外圆粗加工最经济有效的方法。由于粗车的目的主要是迅速地从毛坯上切除多余的金属，因此，提高生产率是其主要任务。粗车通常采用尽可能大的背吃刀量和进给量来提高生产率。而为了保证必要的刀具寿命，切削

16、速度则通常较低。粗车时，车刀应选取较大的主偏角，以减小背向力，防止工件的弯曲变形和振动；选取较小的前角、后角和负值的刃倾角，以增强车刀切削部分的强度。粗车所能达到的加工精度为IT12ITll，表面粗糙度Ra为50125m。2精车精车的主要任务是保证零件所要求的加工精度和表面质量。精车外圆表面一般采用较小的背吃刀量与进给量和较高的切削速度进行加工。在加工大型轴类零件外圆时，则常采用宽刃车刀低速精车。精车时车刀应选用较大的前角、后角和正值的刀倾角，以提高加工表面质量。精车可作为较高精度外圆的最终加工或作为精细加工的预加工。精车的加工精度可达IT8IT6级，表面粗糙度Ra可达1608m。3精细车精细

17、车的特点是：背吃刀量和进给量取值极小，切削速度高达1502021mmin。精细车一般采用立方氨化硼（CBN）、金刚石等超硬材料刀具进行加工，所用机床也必须是主轴能作高速回转、并具有很高刚度的高精度或精密机床。精细车的加工精度及表面粗糙度与普通外圆磨削大体相当，加工精度可达IT6以上，表面粗糙度Ra可达040.005m。多用于磨削加工性不好的有色金属工件的精密加工，对于容易堵塞砂轮气孔的铝及铝合金等工件，精细车更为有效。在加工大型精密外圆表面时，精细车可以代替磨削加工。车刀在结构上可分为整体车刀、焊接车刀和机械夹固式车刀。整体车刀主要是整体高速钢车刀，截面为正方形或矩形，使用时可根据不同用途进行

18、刃磨；整体车刀耗用刀具材料较多，一般只用作切槽。切断刀使用。焊接车刀是将硬质合金刀片用焊接的方法固定在普通碳钢刀体上。它的优点是结构简单、紧凑、刚性好、使用灵活、制造方便，缺点是由于焊接产生的应力会降低硬质合金刀片的使用性能，有的甚至会产生裂纹。机械夹固车刀简称机夹车刀，根据使用情况不同又分为机夹重磨车刀和机夹可转位车刀。通过这样的学习，可以了解到基本的现代制造技术，当然在学习的过程当中会有错误，希望在以后的学习中不会再犯。以上就是本人学习现代制造技术的感想Modern manufacturing technologyIn its content includes metal cutting

19、process and basic rule, machine tool, cutting tool, fixture basic knowledge, mechanical processing and assembly process planning design, mechanical processing precision and surface quality concept and its control method, manufacturing technique, philosophy and modern production management mode, manu

20、facturing technology development frontier and trends. Form with mechanical manufacturing technology as the main application ability training of new curriculum system. This course mechanical product processing principle, manufacturing methods and the equipment and process equipment used as the main r

21、esearch object, discusses the various production conditions, how with the lowest cost, higher labor productivity produce quality products.Parts processing is by machine in tool, workpiece, fixture, consisting of completion, processing craft system in quality, cost, efficiency depends largely on the

22、processing method and thus and choose of machine tools and fixtures and tools. In the past, mechanism of independent setting several professional with specialized course curricula group to build up students combination of machinery manufacturing technology knowledge structure. Due to various curricu

23、lum, self-sustaining, not only relevant content repetition of low starting point, wastes a lot of hours, and various curriculum knowledge is difficult to digest and comprehensive application, go against mechanical manufacturing technology application ability. This course in the content system arrang

24、ement, through the outer circle, inner circle, plane, tooth-type surface and so on, the process of typical processing, machine, jigs, and cutting tools together efficiently, thus strengthening the pertinence and practical, a good solution to the problem.Mechanical manufacturing industry for human su

25、rvival, production, life offers all kinds of equipment, it is extremely important in the national economy based industry. The so-called the four modernizations, in a sense, is to use modern equipment to equipment industry, agriculture, national defence and science and technology enterprise, to reach

26、 the advanced level. Manufacturing for human creating the magnificent material civilization. According to statistics, 90 years 20 industrialized countries of wealth created in the manufacturing sector by gross domestic product (GDP) ratio 22.15%, manufacturing is average for a nations founding of th

27、e company. Manufacturing technology to support the manufacturing healthy development, advanced manufacturing technology makes a countrys manufacturing and even national economy is in competitive position. Ignore manufacturing technologydevelopment, will lead to economic development into guhya way.Ma

28、chinery industry to improve the peoples living quality, promote the progress of science and technology plays an important role.And machinery industrys development and progress, to a great extent, depends on the development of mechanical manufacturing technology. Historically, 1769 watt invented the

29、steam engine, but at that time the processing technique is very backward, suffer from high precision processing not cylinder and cant get application. In 1775, Wilson successfully transformed a cylinder boring, solved this problem. In the following year (1776) steam engine obtaining an actual applic

30、ation and ushered in the first industrial revolution, therefore, mechanical manufacturing technology, the development of science and technology progress human how important role. In science and technology are highly development today, is still so, modern industrial machinery manufacturing technology

31、 to put forward more and more high requirements, such as requirements to the nanometer level (10 - ultra-precision 6mm), large scale integrated circuit wafer of HuaPian superfine processing, heavy equipment super-large parts processing, refractory materials and have special physical properties of ma

32、terials processing, etc, such modern machinery manufacturing technology, to put forward many new problems. Meanwhile, when product design pattern, to improve decision after product quality and productivity, reduce cost, use advanced manufacturing technology is the key. Therefore, in the competition

33、in the future, who master advanced manufacturing technology, who h On the other hand, it is also due to the development of science and technology, and for mechanical manufacturing technology development provides tools and methods, especially the development of computer technology, prompting conventi

34、onal technology and precision detection technology and CNC technology, sensing technology, etc, to mutual combination of mechanical manufacturing causes many new technology, new ideas, and make the quality of our products and production efficiency greatly improved, the current, machinery manufacturi

35、ng technology development mainly displays in the following aspects:To high flexibility and automation direction. With the increasingly fierce competition in international market, mechanical and electrical products update cycle increasingly short, many varieties of small and medium-sized batch produc

36、tion will become a main type of production. How to solve the automation problems small batch production before us is a prominent problem. Therefore, in order to solve medium and small batch production automation as the main target flexible Manufacturing technology of more and more attention, such as

37、 CNC (Computer numerical control), CAD/CAM (Computer - applicants themselves, Computer - applicants Manufacturing Cad/CAM), big Manufacturing System (FMS) application Flexible Manufacturing System is more and more extensive, some developed countries, which are developing CIMS (Manufacturing System i

38、s done Computer Integrated Manufacturing System), make the whole production process under Computer control, not only realize automation, and to realize the Flexible, intelligence, integration, and make product quality and production efficiency greatly improved, production cycle shortens, produced go

39、od economic benefits.as control market initiative.Precision processing and ultra-precision processing machinery manufacturing technology development is another aspect. In the modern high-tech fields, product accuracy requirement more and more high, some cutting-edge products its processing accuracy

40、reached 0.001 um, um, less than Ra0.005 surface roughness is nano (nm) level, prompted by microns (machining accuracy 0.1 1um shape dimension accuracy, the surface roughness as Ra0.03 0.3 to um) sub-micron and nanoscale development. Master ultra-precision processing technology in the future, plays a

41、n important role in technological competition, also is a country manufacturing level of important symbol. To realize the precision and ultra-precision processing, must have corresponding processing equipment, tools, instruments and processing environment and testing technology.High-speed cutting, st

42、rong cutting, improve the machining efficiency is mechanical technology development trend. To realize high speed cutting (cutting speed for common cutting speed is 5 10 times) and strong cutting the key is to have conesponding machine tools and cutting tools. At present numerical control lathe spind

43、le speed has reached 5000r/min, foreign some processing center spindle speed has amounted to more than 20210r/min, grinding speed universal has amounted to 40 60m/s (usually in a 35m/s or so), high has reached 80 120m/s.Before liberation, our machinery industry extremely backward, almost without any

44、 decent machinery industry, the construction of the liberation after more than 40 years, China machinery industry got great development, has made good progress, has built more than 100 industry, machinery manufacturing industry system of national economic sectors electromechanical equipment, has bas

45、ically can be designed manufacturing. But compared with the developed countries, also has the very b ig disparity. Our machine tools in 1993 to numerical control rate is only, and the world developed country were 3.74% has reached more than 70%. Product update cycle length, poor quality, low labor p

46、roductivity, poor economic returns is the mechanical industry common problem. Among them backward mechanical manufacturing technology level is the main reason caused one of the above problems.Machine tools in the machining process also needs a series of supplementary motor, so as to realize the auxi

47、liary motion, all kinds of machine tools for surface forming create conditions, it is a lot of more phyletic, generally include:1) cut cut sport tool relative workpiece certain depth, to ensure that the workpiece meet the required size.(2) dividing sports such as multistage workstation, the cycle of

48、 throats pedicle or shift, bull threaded turning, etc.(3) regulating a movement before the start of relevant parts processing machine the shift, adjusting to the correct cutting tools and relative position between parts.(4) various spare travel sports cutting tool or workpieces quickly before reachi

49、ng and returned movement, drive, parking, change, change to control movement, such as loading, unloading and clamping workpiece, loosen the sports, etc.1) the inner surface of the shingles scraps its appearance is smooth, angled chopped MAO swelling. Processing plastic metal cutting thickness in sma

50、ller, cutting speed is higher, cutting tools rake Angle larger conditions often form such scraps.(2) section shape also called crashing scraps of scraps. Its appearance, angled jagged surface sometimes a crack in. In cutting speed is low and cutting tools rake Angle of bigger, thickness produced suc

51、h small often scraps.(3) granular scraps say again unit scraps. In forming process, such as scraps of shear plane than the material shear stress rupture intensity, scraps units from off the cut materials, forming a granular scraps.(4) collapse of scraps processing brittle material, broken cutting th

52、ickness the bigger the easy to get this kind of scraps.The first three plastic metal scraps is processing when common scraps type. Form bands scraps, the most stable, cutting process of cutting force small ripple, processed surface roughness small; Form when the granular scraps cutting process of cu

53、tting force fluctuation is the largest. The first three scraps type can follow a cutting condition change and transformation, for example, in forming section shape scraps conditions, such as further reduce the anterior horn, reduce the cutting speed or increase cutting, you might have got the thickn

54、ess granular scraps; Conversely, increase the anterior horn, improve the cutting speed or decrease the cutting thickness, can get ribbon scraps.Tool normal wearing of form has the following kinds:1. Former knife knife with worn2. With worn after 3) before and after boundary wear (sword surface and w

55、ear)From the perspective of temperature dependence, tool normal wear are the main reasons why abrasion and thermal and chemical wear. Mechanical wear is hard spots by the workpiece material in the role of the cause, hot characterizations, chemical wear is by bonding (tool and workpiece material cont

56、act to the atom produced when the distance between the combination of spread (phenomenon), the cutter and workpiece two friction chemical element to each other diffusion, corrosion) caused.(1) particle attritionIn cutting process, tools is often some hard spots on carving out the cleft two-tone. Par

57、ticle attrition of HSS role is obvious.(2) adhesion wearTool and workpiece material contact to the atom produced when the distance between the combination of binding phenomenon, said. Interface adhesion wear is due in bonded to produce shear slide in destruction. Low, medium speed cutting, adhesion

58、wear is carbide cutting tools of the main wear reasons.(3) diffusion wearWhen under high temperature effect on cutting, interface, molecular activity energy between caused alloy element diffusion replacement, make the cutting tool material mechanical properties is reduced, then through friction role

59、, if tool is easy to wear. Diffusion wear is a chemical properties of wear and tear.(4) phase change wearWhen the highest temperature over material tools, tools and temperature in surface microstructure change. If martensite organization transformation for austenitic, make the hardness, wear down intensified. Therefore,