第一篇：机电专业英语第2版电子教案unit 19
Unit 19 Introduction to a Microcontroller I.Lead in Nowadays microcontrollers are used in almost all kinds of automatically controlled products and devices, such as automobiles, remote controls, office machines, appliances, digital cameras, cell phones and toys.We can say that microcontrollers are everywhere around us, and they are closely related to our life.Do you know what a microcontroller is? What are the major differences between the microcontroller and the general-purpose microprocessor used in a PC? What are the important features of the Intel 8051 family? After learning this unit, you will get a better understanding of these questions.In this unit, we’ll learn some general information about the microcontroller and the Intel 8051 family.First, let’s study some new words and phrases together.II.Word Study 1.display [,dis'plei] n.显示器；展示；陈列，展览 vt.展示；显示，表现；陈列
1）At present, a video camera and display are no match for the human eye.目前，摄影机和显示器的品质仍然比不上人类的眼睛。2）We need a range of samples for display and publicity.我们需要大量的样品坐陈列与宣传用。
3）The species that make up natural ecosystems usually display a wide range of genetic variability.构成自然生态系统的生物种，通常表现有较大范围的遗传变异性。2.integrate ['intiɡreit] vt.使结合，使合并，综合 vi.成为一体，合并 adj.整体的，完整的，完全的
1）The training program helps children integrate theories with their field experience.这个训练课程能够帮助学生将实际的经验与理论结合。
2）The trend is to integrate the memory arrays and controller circuits of a system together on one or more integrated circuit chips.趋势是将系统的存储器阵列和控制器电路一起集成在一个或一个以上集成电路芯片上。
3）There is no integrate system of procedure of enforcement undertaking in our law.我国法律对此没有形成一个完整的程序体系。
3.adequate ['ædikwit] adj.充足的；适当的；胜任的 1）Is there adequate data for the indicators chosen? 是否有充足的数据以供指标选择？
2）The installation must also allow for adequate drainage from the air gap and the discharge line if needed.如果需要的话，还必须允许从气隙和排放管道里有适当的排放。4.access ['ækses] vt.使用；存取，访问；接近n.进入；使用权
1）Client is computer or a software program that can access particular services on the Internet.客户是可访问因特网上某些具体服务的计算机或软件程序。
2）Host(computer)is a computer that a user can connect in order to access information or run programs.主机是用户为了存取信息或运行程序所要连接的计算机。3）I have read-only access to my bank files.我用只读方式存取我的银行文件。
5.cement [si'ment] vt.巩固，加强；(用水泥等)粘合 n.水泥
1）The company must now decide whether to cement the well from the top.该公司现在必须决定是否用水泥从顶部彻底封堵油井。
2）Our object is to further cement friendly relations between the two countries.我们的目的是进一步加强两国之间的友好关系。
6.debug [di:'bʌɡ] vt.调试；排除故障 n.调试器，排错器
1）Debug and maintenance the test program and test equipment in daily work.对测试程序以及测试设备进行调试和维护。
2）There are still mechanical linkages to build, control programs to debug.目前还有些机械环节要制作，还有些控制程式要除错。
III．Language points 1.The engine is controlled by a microcontroller, as are the anti-lock brakes and so on.译文：发动机、防抱死制动系统等等都是用单片机控制的。
说明：句中anti-lock brake 表示防抱死制动系统或防锁死煞车系统，可安装在任何带液压刹车的汽车上，能避免在紧急刹车时方向失控及车轮侧滑。“as” is a substitute for a clause，and it can be replaced by “so”(……也一样)，e.g.1)She is a doctor, as/so is her husband.她和她丈夫都是医生。
2)Business confidence has picked up, as/so has the Paris Bourse.商业信心有所提升，巴黎证券交易所的交易情况也有好转。
2.Any device that has a remote control almost certainly contains a
microcontroller: TVs, VCRs and high-end stereo systems all fall into this category.译文：任何具有远程遥控的设备都几乎肯定包含一部单片机：电视机、录像机、高端立体声音响系统都属于这一类。
说明：“that” is a relative pronoun used to introduce an attributive clause modifying “device”.“fall into” means “be included in or classified as, belong to”(归入，属于，分成；陷入), e.g.1)Going forward, these cases will fall into five distinct categories.接下来，这些案件将被归入五大类别。2)Old civilization may fall into decay.古老的文化可能会渐渐衰落下去。
3)In particular, diodes – and perhaps more surprisingly – resistors fall into this category.其中很特别的就是二极管和电阻也属于这样的元器件类型。
4)Programming languages fall into two major categories: low-level assembly languages and high-level languages.程序设计语言主要分成两类：低级汇编语言和高级语言。
3.Basically, any product or device that interacts with its user has a microcontroller buried inside.译文：任何与用户进行互动的产品或设备内部都嵌有单片机。
说明：“that” is a relative pronoun used to introduce an attributive clause.“buried inside” is a past participle phrase modifying “microcontroller”.“interact with” means “act together with others”(与……互动或相互作用), e.g.1)But because these particles are electrically charged, they also interact with the Earth's magnetic field.但是因为这些粒子是带电的，所以它们会受地球磁场的影响。
2)A display device that allows the user to interact with a data processing system by touching an area on its screen.一种允许用户通过触摸屏幕上某一区域以对数据处理系统进行交互操作的显示装置。
4.It is a microprocessor emphasizing high integration, in contrast to a general-purpose microprocessor(the kind used in a PC).译文：与应用在个人电脑中的通用型微处理器相比，它是高度集成的微处理器。
说明: “emphasizing high integration” is a present participle phrase used as an attribute modifying “microprocessor”.“in contrast to” means “与…对比(或对照)；与…相反”
1)The gaiety and lightness of his work were in contrast to his own sad
nature.他的作品的欢乐与轻快与他哀伤的性格形成鲜明的对照。
2)In contrast to her elder brother, she was always considerate in her treatment of others.和她哥哥完全不一样，她对别人总是很体贴。
5.Power consumption while sleeping may be just nanowatts, making them ideal for low power and long lasting battery applications.译文：睡眠时消耗功率可能只有纳瓦级(10﹣9 W)，所以很适宜应用在低功耗且长期用电池供电的场合。
说明：“sleeping” is a present participle used as an adverbial of time.It has the same function as an adverbial clause of time.“making them ideal for low power and long lasting battery applications” is a present participle phrase used as an adverbial of result.“be ideal for” means “be suitable for, be appropriate for”(对……很理想，适用于……), e.g.1)The cable system is ideal for spanning natural barriers of wide rivers, deep valleys, or ravines.这种钢索体系是跨越宽河道、深丘谷或深山谷天然障碍物的理想体系。2)Unlike incandescent or fluorescent lamps, which spew light in all directions, LEDs generate directional light, making them ideal for selectively illuminating areas.不像白炽灯或者荧光灯那样灯光四射，LED产生的是定向光，定点照明的理想之选。
6.Intel’s original 8051 family was developed using NMOS technology, but later versions, identified by a letter “C” in their name, e.g.80C51, used CMOS technology and were less power-hungry than their NMOS predecessors.译文：英特尔最早的805l系列是用NMOS技术开发的，但后来的标以“C”字母如80C51的版本是用CMOS技术开发的芯片。
说明：“using NMOS technology” is a present participle phrase used as an adverbial of manner.“identified by a letter “C” in their name” is a past participle phrase used as an attribute.It can be replaced by an attributive clause.“power-hungry” means “consuming a lot of power”(高耗电的), e.g.1)The new lines will be used to carry electricity from coal-rich inland provinces to the power-hungry coast.新输电线路将用于连接中国煤炭资源丰富的内陆省份和电力短缺的沿海地区。
2)The power amplifier plays an important role in a modern wireless communication system and is the most power-hungry device.在现代化的无线通讯系统中功率放大器扮演一个重要的脚色，它往往是最消耗功率的元件。
IV.Translating Skills
长难句的翻译
对于每一个英语句子的翻译，并不只是使用一种翻译方法，而是多种翻译方法的综合运用，这在英语长句的翻译中表现得尤为突出。长句的翻译，关键在于理解分析。由于连词、冠词和介词等功能词的作用，和非谓语动词及谓语动词等结构形式的存在，使得英语长句的修饰成分相当复杂，可以是单词、短语，也可以是从句，而且这些修饰成分还可以一个套一个地使用。再加上英汉句子语序上的差异，如定语和状语修饰语的位置差异、句子的逻辑安排差异等，这就使得英语句子结构复杂，长句较多，有时一段可能只有一句话，只要方法得当，长句的翻译并不难。
一、长难句分析的步骤
1．结合具体语言环境了解全句大意。
2．剖析全句，分清主要成分和次要成分，主句和从句。
3．紧缩主干，确定句子的主、谓语，找出句子的基本构架，及其所属句型。
4．疏通脉络，清理枝蔓，分清主次关系，注意上下层次，前后引衬及其逻辑关系。
5．按汉语造句的规律，进行选词和语序的调整。
6．反复研究译文，进行词句锤炼的润饰工夫，最后定稿。Sample: For a family of four, for example, it is more convenient as well as cheaper to sit comfortably at home, with almost unlimited entertainment available, than to go out in search of amusement elsewhere．
分析：
该句的骨干结构为“it is more…to do sth than to do sth else”是一个比较结构，而且是在两个不定式之间进行比较；该句中共有三个谓语结构，它们之间的关系为：it is more convenient as well as cheaper to…为主体结构，但it是形式主语，真正的主语为第二个谓语结构：to sit comfortably at home，并与第三个谓语结构to go out in search of amusement elsewhere作比较。
综合上述翻译方法，这个句子我们可以翻译为：譬如，对于一个四口之家来说，舒舒服服地在家中看电视，就能看到几乎数不清的娱乐节目，这比到外面别的地方去消遣又便宜又方便。
二、长难句的四种翻译方法 1．顺译法
顺译法就是按照原文时间、方位、逻辑等顺序将长句的内容再现，例如： Even when we turn off the beside lamp and are fast asleep, electricity is working for us, driving our refrigerators, heating our water, or keeping our rooms air-conditioned.分析：该句子由一个主句、三个作伴随状语的现在分词以及位于句首的时间状语从旬组成，共有五层意思：A．即使在我们关掉了床头灯深深地进入梦乡时；B．电仍在为我们工作；C．帮我们开动电冰箱；D．加热水；E．或是室内空调机继续运转。上述五层意思的逻辑关系以及表达的顺序与汉语完全一致，因此，我们可以通过顺序法，译为：
即使在我们关掉了床头灯深深地进入梦乡时，电仍在为我们工作；帮我们开动电冰加热，或使室内空调机继续运转。
2．倒译法
在翻译有些长句时，要想使译文通顺、符合汉语表达习惯，翻译时必须从后往前译，这就是倒译法。譬如：
It therefore becomes more and more important that, if students are not to waste their opportunities, there will have to be much more detailed information about courses and more advice.因此，如果要使学生充分利用他们（上大学）的机会，就得为他们提供大量关于课程的更为详尽的信息，作更多的指导。这个问题显得越来越重要。
3．分译法
分译法是将长句拆开来，将其中从句或短语译成短句，分开来叙述，如： Television, it is often said, keeps one informed about current events, allows one to follow the latest developments in science and politics, and offers an endless series of programs which are both instructive and entertaining.分析：在此长句中，有一个插入语“it is often said”，三个并列的谓语结构，还有一个定语从句，这三个并列的谓语结构尽管在结构上同属于同一个句子，但都有独立的意义，因此在翻译时，可以采用分句法，按照汉语的习惯把整个句子分解成几个独立的分句，此句可译为：
人们常说，通过电视可以了解时事，掌握科学和政治的最新动态。从电视里还可以看到层出不穷、既有教育意义又有娱乐性的新节目。
4．综合法
要求我们把各种方法综合使用，先仔细分析，或按照时间的先后，或按照逻辑顺序，顺逆结合，主次分明地对全句进行综合处理，以便把英语原文翻译成通顺的汉语句子。例如：
People were afraid to leave their houses, for although the police had been ordered to stand by in case of emergency, they were just as confused and helpless as anybody else.尽管警察已接到命令，要作好准备以应付紧急情况，但人们不敢出门，因为警察也和其他人一样不知所措和无能为力。
V.Key to the Exercises
Key to Exercises of the text I.1.Sixteen kinds of products or devices are listed.They are microwave ovens, modem automobiles, TVs, VCRs, high-end stereo systems, digital cameras, cell phones, camcorders, answering machines, laser printers, telephones(the ones with caller ID, 20-number memory, etc.), pagers, and refrigerators, dishwashers, washers and dryers(the ones with displays and keypads).2.A microcontroller is a computer system-on-a-chip, containing a processor, memory, and input/output functions.3.In contrast to a general-purpose microprocessor, the microcontroller integrates additional elements such as read-write memory for data storage, read-only memory for program storage, EEPROM for permanent data storage, peripheral devices, and input/output interfaces.4.The two particularly useful features of the 8051 core are the inclusion of a Boolean processing engine and four separate register sets.II.1.T
2.T
3.T
4.F
5.T
6.F III.1.anti-lock brakes
2.read-write memory for data storage 3.general-purpose microprocessor
4.two-level interrupt priority 5.A microcontroller is a computer system-on-a-chip, containing a processor, memory, and input/output functions.Key to Exercises of the reading 1.An assembler is a software tool designed to simplify the task of writing computer programs.2.To effectively write assembly programs, a person should understand both the microcomputer architecture and the assembly language.3.An assembly program has three constituent parts: machine instructions, assembler directives and assembler controls.4.Detailed discussion of the machine instructions can be found in the hardware manuals of the 8051 family or other microcontrollers.VI.阅读材料参考译文
汇编程序是什么？
汇编程序是一种用来简化计算机编写程序的软件工具。汇编程序把符号
化的代码（汇编指令）编译成可执行的目标代码（机器指令），然后把该目标代码编入单片机（的程序存储器）中并加以执行。汇编语言程序可直接译成CPU指令，命令处理器完成相应的运算。所以，要有效地编写汇编语言程序，就需要对微型计算机的结构和汇编语言都很熟悉。
汇编语言操作代码很容易记（MOV就是移动指令，ADD就是加法指令等等）。还可以用符号表示（存储器）地址和指令的操作字段值。
因为指定了这些名字，指令就有了意义，比较容易记忆。比如，如果你在程序中要多次用到一个日期作为数据，你可以给这个日期指定一个符号化的名字DATE（日期）。如果你程序中含有用作延时循环的一组指令(在指定的时间内反复执行的一组指令)，你可以给这段指令起名TIMER—LOOP。
汇编程序有3个组成要素：（1）机器指令。（2）汇编指令。（3）汇编控制。
机器指令就是可以由CPU执行的机器代码。对机器指令的详细讨论可以参看8051系列或其他单片机的硬件手册。
汇编指令用于定义程序的结构和符号，生成非执行代码（数据、信息等）。汇编控制设置汇编程序的模式和流向。
第二篇：机电专业英语第2版电子教案Unit 2
Unit 2 Machine Elements I.Lead in Information related to the text Do you know what is referred to as a machine element? Which elements are associated in pairs? Can you give an example? What is the most common machine element? How can the supporting structure be assembled? Why does the individual reliability of machine elements become the basis for estimating the overall life expectancy of a machine? Maybe you have seen and you are much interested in some machine elements, of course also interested in these questions.In this unit, you’ll learn some machine elements and know how they are widely used in industry.Now, let’s study new words and phrases together.II.Word Study 1.individual [,indi'vidjuəl] adj.个别的n.个人,个体 1）These styles can be adapted to suit individual tastes.这些式样均可改动以适应个人不同的爱好.2）Who was the individual champion? 谁是个人项目的冠军？
3）Am I a Business or Individual account? 我采用企业帐户还是个人帐户？ 2.dismantle [dis'mæntl] v.拆除．．．的设备, 分解
1）To dismantle or raze;tear down.拆除，毁坏：拆除，摧毁；拆毁 2）Before mounting, You can not dismantle the plug of port in case the dirty entering.装机前不得将各油口堵塞拆掉，以防脏物进入。
3）The pressure test is over.Now decrease the pressure , dismantle the pipe and check the inside of the pipe.压力试验通过了，把压力放掉，拆开管子，检查管子内部。3.perform [pə'fɔ:m] v.执行,表演,做
1）Lasers can be used to perform operations nowadays.现在激光可以用来做手术。
2）To perform operations on data in a process.对一个过程﹝进程﹞中的数据进行操作。
3）Able to assemble and disassemble molds and perform mold repair work as instructed.能够组装和拆卸注塑模具，并按规定进行模具维修工作。
4.associate [ə'səuʃieit] n.同伴, 伙伴
v.联合, 联想
adj.副的 1）I don't want to associate myself with them any more.我不愿再和他们交往了。
2）She associated happiness with having money.她把幸福和有钱联想到一起。
3）We should associate ourselves with the large firm.我们应该和这家大公司联合。
4）Medias associate tightly with the society, closes to personal life, people can touch the pulse of the community.传播媒介于社会联系密切，与人民生活息息相关，人们可感觉到社会的脉搏。
5.evolve [i'vɔlv] v.进展，进化，展开
1）The American constitution was planned;the British constitution evolved.美国宪法是精心制定的, 英国宪法是约定俗成的.2）No one can process and evolve for another.没有人能为别人推移和进化。
3）Your raising of consciousness through love and responsibility nourishes us, replenishes us, and expands our consciousness so that we may evolve further.通过爱和责任滋养我们、补充我们，我们意识提升，并且扩展我们的意识以便我们能进一步进化。
6.expectancy [ik'spektənsi] n.期待(公算)1）A quiver of expectancy ran through the audience.全场引颈以待, 群情鼎沸.2）Women have a higher life expectancy than men.女人比男人的预期寿命长.3）Greatly increased life expectancy and control board system reliability.大大提高控制线路板寿命和系统可靠性。
III．Language points
1.However simple, any machine is a combination of individual components generally referred to as machine elements or parts.译文：无论怎样简单的机床,都是由通称为机械零件或部件的单一元件组成的.说明：“be referred to as” means “be known as” or “be regarded as”(称为、叫作)，e.g.1)PMO can also be referred to as a “program management office, ” “project office, ” or "program office.项目管理办公室也可以叫作“计划管理办公室”或“计划办公室”。
2)Including credit cards, debit cards, online payment gateway and all other non-cash, to pay the bills, should be referred to as electronic payments.包括信用卡、借记卡、线上网关支付等一切非现金、票据支付的方式，都应该称为电子支付。
2.If a machine is completely dismantled, a collection of simple parts remains such as nuts, bolts, springs, gears, cams and shafts—the building block of all machinery.译文：如果把机床完全拆开, 就可以得到像螺母,螺栓,弹簧,齿轮,凸轮及轴等简单零件—所有机器的组合元件.说明：“dismantle” means “take sth.to pieces”(拆开, 拆除)
“a collection of ” means “a group of ” e.g.1)Installation & Dismantle： 展台搭建和撤展，常简称为“I &D”。2)The new government dismantled their predecessors' legislation.新政府废除了前任政府的立法。
3)Trouble is, after the inspection, people take down the fences or dismantle the alarms.问题是，在通过检查后，人们会拆掉护网或警报器。
3.A machine element is, therefore, a single unit designed to perform a specific function and capable of combining with other elements.译文：因此，机械零件就是用来设计可以执行某一特定功能，且能与其它零件配合的单一元件。
分析：“designed to perform a specific function and capable of combining with other elements” is a past participle phrases used as attribute to modify “a single unit”, it has the same function as an attributive clause.说明：“perform” means “carry out”（执行，完成）e.g.1)When to perform update, progress input is control by process, not software.何时执行更新，进度输入是过程控制，不是软件控制。2)You can also perform a test.你也可以进行一个测试 3)Perform other tasks as required.完成要求的其他任务； “be capable of” means “be able to do”
A teacher must be capable of great patience.This is largely a matter of self-training.一名教师必须具有极大的耐心，在很大程度上这是个个人修养问题。4.The most common example of a machine element is a gear, which, fundamentally, is a combination of the wheel and lever to form a toothed wheel.译文： 机器零件中最常见的是齿轮,它实际上是由轮子和杆组成的带
有齿的轮子。
分析：which introduces a nonfinite attributive clause to modify gear.The infinitive phrase “to form a toothed wheel” is used as adverbial to express result.5.Other fundamental machine elements have evolved from wheel and lever.译文：其他基本机械零件是由轮子和杆逐渐发展而来的.说明： “evolve from” means “develop from”
evolve [i'vɔlv] vt.发展，进化；进化；使逐步形成；推断出 vi.发展，进展；进化；逐步形成 e.g.1)Strategic goals evolve from the mission of the organization.策略的目标从组织的任务进展。
2)Great historical achievements often evolve from simple concepts.历史上的壮举，往往是从朴素的概念演变过来的。
3)No one can process and evolve for another.没有人能为别人推移和进化。
6.standardize ['stændədaiz] v.标准化，使合于标准
1)Should perfect administration further to hearing system, make it standardized and legal.应当进一步完善行政听证制度，使其规范化、法定化。
2)This paper aims at building different types of software fault models to manage and standardize these faults.这篇文章旨在建立不同类型的故障模型，以便于管理和标准化这些故障。
7.establish [is'tæbliʃ] v.建立，确立，创办
1)Our company was established in 1994.我们的公司成立于1994年。2)We wish to establish business relations with you.我们希望能和你们建立业务关系。
3)Prices branch, only prices branch has the right to establish the price.物价部门，只有物价部门有权利制定价格。
IV.Translating Skills
词义的确定
英汉两种语言都有一词多类、一词多义的现象。一词多类是指一个词往往属于多个词类，具有几种不同的意义。如display一词，既可做名词“显示（器）”，又可以作形容词“展览的、陈列用的”，还可做动词“显示、表现”等意思。一词多义是说同一个词类中，往往有几个不同的词义。如power 一词，做名词时，其汉语意思为“电力、功率、次方”等。在英汉翻译过程
中，我们在弄清句子结构后就要善于选择和确定句子中关键词的意义。选择和确定词义通常从以下几个方面入手：
一、根据词类确定词义
选择某个词的词义时，首先要确定这个词在句中应属于哪一种词类，然后再进一步确定其词义。下面以display为例：
Here, you have the option of defining your own display variants.这里，你有权定义你自己的显示变式。（display为名词）Often, it is best to display materials on an information table.通常，最好是把资料放在提供各类资讯的桌子上展示。（display为动词）
The reverse side of a control panel, display panel, or the like: the side with the interconnecting wiring.（display为形容词）
控制面板、显示面板或类似的面板的反面，即带有互连接线的那一面。
二、同一词类表达不同词义
英语中同一个词，同一类词，在不同的场合，往往具有不同的含义。此时，必须根据上下文的联系及整个句子的意思加以判断和翻译。例如as 这一连词：
Wear resistance improves as cutting tool hardness increase.当切削刀具的硬度越高时，其耐磨性就越好。（as引导时间状语从句）
As heat makes things move, it is a form of energy.因为热能使物体运动，所以热是能的一种形式。（as引导原因状语从句）
三、根据单词搭配情况确定词义
英译汉时，不仅必须根据上下文的联系理解词义，还需要根据词的搭配情况来理解词义。尤其在科技文献中，由于学科及专业不同，同一个词在不同的专业中具有不同的意义。比如：
The fifth power of two is thirty-two.二的五次方是三十二。（数学）With the development of electrical engineering, power can be transmitted over long distances.随着电气工程的发展, 电力能输送得非常远。（电学）Friction can cause a loss of power in every machine.摩擦能引起每一台机器功率的损耗。（物理学）
同一个词与不同的词搭配，可以产生不同的词义。如： make contact 闭合电路
make metals熔炼金属 make good
修理补偿
make a circuit接通电路
make up
补偿，配制
make over转让，移交
四、根据名词的单复数选择词义
英语中有些名词的单数或复数表达的词义完全不同。例如： 名词
单数词义
复数词义
facility
简易，灵巧
设施，工具 charge
负荷，电荷
费用 spirit
精神
酒精 Although they lost, the team played with tremendous spirit.那队输是输了，但却表现了极其顽强的精神。Whisky, brandy, gin and rum are all spirits.威士忌、白兰地、杜松子酒和朗姆酒都是烈酒。
V.Key to Exercises of the text.I 1.A machine element is a single unit designed to perform a specific function and capable of combining with other elements.The most common machine element is a gear.2.Other fundamental machine elements have evolved from wheel and lever.3.In the automotive industry only fasteners, bearings, bushings, chains, and belts are standardized.II.1.F
2.T
3.T
4.T
5.T
6.F III.1.最常见的机械零件是齿轮，实际上是由轮子和杆组成的跌有齿的轮子。
2.齿轮的坚硬性决定了它的耐磨能力。
3.制造业的工程师们集中精力，研制标准化的零件。
4.这些零件是以大批量、高规格和降低成本的条件下生产的。Key to Exercises of the reading 1.The most important properties of cutting tools are hardness at high temperature, wear resistance, and impact strength.2.The hardness of the tool and the degree to which it remains its hardness at high temperature are important in the selection of a cutting-tool material.Because all metal cutting tools begin to lose hardness when heated to sufficiently high temperatures.3.The various materials from which most metal cutting tools are made can be classified under the following principal headings: Carbon tool steel，High-speed steel, Cast alloys, Cemented carbides, Ceramics, Diamonds.4.In order to detect the time when a cutting tool should be changed.VI.阅读材料参考译文
切削刀具
金属切削刀具必须具有许多不同的性能，才能在各种恶劣条件下切削不同的金属。为满足这些要求，制作刀具需要用许多种材料。
切削刀具的性能
切削刀具最重要的性能是在高温下能保持的硬度以及耐磨损耐冲击和韧性好。
当刀具进行切削时，刀具刃口处的压力和摩擦产生了高温。达到一定高的温度时，所有的金属切削刀具便开始软化。在刀口因高温而软化的同时，刀具刃口便开始磨耗并损坏。不同的切削刀具材料在不同的温度点开始软化。因此，刀具的硬度和它在高温下所能保持的硬度是选择切削刀具材料时的重要因素。
如果切削刀具的刃口和刀面耐磨，刀具就不易磨损。切削刀具的硬度越高，耐磨性就越好。
切削刀具还必须具有高强度才能抗振动和抗冲击。切削刀具材料的强度并不都是与硬度成正比的。有些硬的刀具材料由于太脆而缺乏强度。
切削刀具材料
大多数金屑切削刀具的制作材料可分为以下几大类：
碳素刀具钢；高速钢；铸合金；硬质合金；陶瓷；金刚石。
刀具寿命，即切削刀刃在需要重新打磨之前能加工的零件数，是生产某个零件或产品的重要成本因素。当切削刀具开始变钝时必须重新打磨。如果在这时还要继续用下去，刀具会很快地磨损。
要知道什么时候该换刀具，大部分现代机床都安装了指示器来显示切削加工所耗的功率。当刀具用钝时，加工需要消耗更多的功率，并由指示器显示出来。一旦发生这种情况就应当立即打磨刀具。
第三篇：机电专业英语第2版电子教案Unit 25
Unit 25
Digital Television I.Lead in
Information related to the text Do you know what is referred to as digital technology? What is digital technology applications? Do you understand digital TV? How it works? What are the advantages of it? In this unit, you'll learn some concepts and applications of digital technique and digital TV working principle and its advantages.Now, let's learn new words and phrases.II.Word Study 1.transmit [trænz'mit] vt.传达；传输；发射vi.发射信号；传输 1）Solids transmit sound very well.固体能很好地传导声音。
2）Our fax cannot transmit to your fax machine.我们无法把文件传到你们的传真机。
2.electromagnetic [i,lektrəumæɡ'netik] adj.[电]电磁的 1）Light is an electromagnetic wave!光确实是一种波！
2）As their name suggests, electromagnetic waves contain both an electric field and a magnetic field.顾名思义，电磁波是由电场及磁场所构成。
3.multifunctional [,mʌlti'fʌŋkʃənl] adj.多功能的 1）Please show me the way to the multifunctional hall.请告诉我多功能厅怎样走。
2）It is the good friend I have, a multifunctional friend.我的好朋友就是他，一个七十二变的好朋友。4.retrieve [ri'tri:v] v.重新得到
1）It can store and retrieve data at(very high speed).它可以（极高速）存贮及读取资料。
2）I ran back to retrieve the bag I had left in the train.我跑回去找回忘在火车上的包。
5.interference [,intə'fiərəns] n.干扰, 干涉。1）High resistance to white interference.高抗白光干扰能力。
2）So is most interference in free markets.自由市场中的大部分干预手段亦是如此。
6.innovative ['inəuveitiv] adj.创新的, 革新(主义)的
1）That is a very innovative training course.这项培训课程是很有创新。
2）Business schools thus need to scour the globe for role models, innovative ideas and the best students.因此商学院必须在全球范围内网罗行为榜样、创新的想法和最优秀的学员。
在这种思想的影响和指导下，中国古代出现许多盛世。III．Language points 1.It is a system of sending and receiving pictures and sound by means of electronic signals transmitted through wires and optical fibers or by electromagnetic radiation.译文：它是一个利用电线、光纤或电磁辐射发射的电信号来发送和接收图像与声音的系统。
说明：“by means of” 意为“用，依靠”，又如：
1）He succeeded by means of perseverance.凭着坚忍不拔的毅力，他成功了。
2.By way of example, the application of digital technology to our telephone service has not only improved the quality of service but has also enabled the development of value-added services such as interactive enquiry and phone-banking services.译文：例如, 数字技术在电信服务方面的应用不仅改善了服务的质量, 而且还使一些增值服务得到了发展, 比如像交互式查询和电话银行服务。
说明：“by way of example”意为“顺便举个例子”此处译为“例如”，又如：I say so by way of example.我这样说只是举个例子而已。
“not only … but also”意为“不仅…而且”eg：
1）He plays not only the piano but also the violin.他不仅会弹钢琴，而且还会拉小提琴。
3.With the forthcoming third generation mobile phone technology, even multimedia services can be provided.The traditional television set will be turned into a multifunctional media receiver, meeting various demands of users.译文：随着第三代移动电话技术的来临, 将来还可以提供多媒体服务。传统的电视机将转变为多功能的媒体接收机, 以适应用户的多种需求。
说明：“turn into” 意为“进入，由一种状况进入另一种状况”eg： 1）Water turns into ice when it freezes.水凝固时变成了冰。
4.Analogue transmission technology converts sound and pictures into continuously varying electric signals which after transmission, are converted back to sound and pictures by television sets.译文：模拟传输技术将声音和图像转换为连续变化的电信号；在传输结束之后, 这些电信号由电视设备再还原成为声音和图像。
说明：“convert…into” 意为“把…变成（转化成）”eg：
1）The purpose of elctric circuits is to distribute and convert energy into some other forms.电路的用途是分配能量，以及将能量转化为其他形式。
5.The difference in quality between digital television and regular television is similar to the difference between a compact disc recording(using digital technology)and an audiotape or long-playing record.译文：数字电视与普通电视之间的品质差异就像使用数字技术的光盘唱片与录音磁带或长时问唱片之间的差异。
说明：“be similar to” 意为“与…相似/相像” eg： 1）Gold is similar in color to brass.金和铜的颜色相似。
6.Under the analogue environment, television signals are subject to interference by other signal sources such as power line, reflections from buildings, etc.译文：在模拟环境中, 电视信号会受到来自其他信号源的干扰, 比如电力线、建筑物的反射等, 因此接收质量要低于理想情况。
说明：“such as ” 表示举例，意为“例如，诸如此类的，像…样的” eg：
1）Annimals such as rabbits and deer continue to be active all winter，fingding food wherever they can..像兔和鹿这样的动物整个冬天都是很活跃的，他们到处寻找食物。
IV.Practical English
面试技巧
如何在英语面试中脱颖而出？在口语面试中应该避免哪些内容？以下总结了英语面试中的几点技巧和具体应对策略，希望能对面试者有所帮助。
一、面试技巧 1.面试中要自信
英语面试以考查英语应用能力为主，小组讨论是英语面试的重要一环。一般来说，小组讨论形式的面试其目的主要是要了解应聘者在团体中的工作反应，所以应聘者在面试中最需要的是自信、敢说。注意在互动过程中要多使用口语化的表达，尽量采用简短明了的词汇来表达自己的意思，说话要流利，思维要连贯，层次要清晰，可以用“well”、“however”这样的过渡词来给自己停顿和思考。
2.面试前了解一下企业情况
在面试前不妨去公司的英文网站了解一下企业情况。必须准确了解应
聘公司的外语使用程度和目的等信息后，并做出相应的对策。
3.注意英语时态的变化运用
面试过程中，往往会涉及到很多关于个人经历，教育背景，工作经验，职业规划等方面的问题，因此在表述某件事情或是某个想法的时候，一定要注意配合正确的时态，否则就会造成差之毫厘，失之千里的后果。例如：你已经参加过某项专业技能培训与你正在参加或计划参加就是完全不同的。
4.尊重个人及文化差异
主要有两种做法要特别注意避免。首先是要避免使用过于生僻的单词，或是地方俚语之类接受群体相对比较小的表达方式。因为这种表达方式很有可能造成听者的困惑与曲解。其次则是要避免过多、过于主观地谈及宗教文化或时事政治方面的问题。因为面试官很有可能来自不同的国家与地区，有一定的个人倾向。因此作为面试者，在不了解情况的状态下，如果谈到此类话题，要谨慎而有节制的发言。
二、具体应对策略 1.介绍自己
Could you say something about yourself? 你可以从以下几个方面突出自己：职业技能强项，该技能的深入程度，该技能完成过的项目以及自己其他相关方面的深入研究和学习、探索，注意突出个性。不要在自己的姓名、年龄、毕业学校、兴趣爱好等方面浪费时间，也不用再把你的简历背诵一遍。
2.应聘动机
What makes you come here today? 面试官想了解一下你的求职动机，看看你对公司是否有所了解。在回答这个问题的时候要充满信心，不要说是来试试的（Do you really want to take a try?）。要事先将公司信息整理好，和自己的职业技能相结合来介绍。
3.教育背景
回答这个问题要简明扼要，实话实说。4.工作经验
回答此问题要充分显露自己的实力，但同时要避免给人炫耀之感。
5.工作要求
要充分表现能胜任的信心。
6.性格爱好
要表现积极合作的一面。7.你的弱点
What do you think is your greatest weakness? May I know it? 客观地评价一下自己确实存在但对工作并不重要的缺点是一个不错的
办法，但要提一下你将采取什么样的办法来克服或弥补自己的缺点。
8.你过去的工作
How do you like your last job? Why did you leave your last job? 面试官想通过你对过去的工作的看法，了解你对今后的工作态度。不要说你不喜欢过去的工作，可以谈谈过去的工作特点和你所负责的主要任务，但要突出过去的工作趋于平淡且失去挑战性，你可以在更艰巨的任务和岗位中发挥能力。
9.你将来的打算
How long do you propose to work here? 简洁的几句话表达出你希望在这个公司一直工作下去即可，同时要体现出你的上进心，渴望与公司一起发展和进步，不断提升自己。
V.Key to Exercises of the text.Ⅰ.Television is a system of sending and receiving pictures and sound by means of electronic signals transmitted through wires and optical fibers or by electromagnetic radiation.2 The benefits of DTV are : 1 efficient utilization of bandwidth.2.better picture and sound quality.3 innovative services.transmit TV programs as well as data, E-commerce.4.governmment′s policy initiatives.DTV is a new way of transmitting television services.Sound and pictures are processed electronically into digital signals, which are then transmitted as a bit stream and reconverted by digital TV sets or appropriate set-top boxes into television programs.Ⅱ.数字-模拟信号转换器模拟电视 interactive programs data transmission sevices Digital Television(DTV)is an advanced broadcasting technology that has transformed your television viewing experience.DTV has enabled broadcasters to offer television with better picture and sound quality.It also offers multiple programming choices, called multicasting, and interactive capabilities.Key to Exercises of the reading 1.Broard Band Communication 2.CATV（Cable Television）
3.Communication Satellite
4.DVB（Digital Video Broadcasting）
VI.阅读材料参考译文
交互式有线电视和机顶盒
数字式交互电视不仅提供新的交互式服务项目，例如通过最先进和最灵活的数字有线电视适用解决方案进行因特网访问、电子邮件和视频点播，而且还提供新的数字节目源。
数字网络系统业务正经由有线电视先进的电缆系统和机顶盒终端设备来帮助有线电子工业先驱进入到一个交互式数字电视新时代。集成的硬件和软件解决方案大大增加了有线电视经营者能提交给消费家庭的信息量，并能使经营者提交数字质量的视频和音频，更丰富的内容和像高速因特网访问、丰富的视频点播那样新的交互式服务以及电子商店应用和增强广播。
机顶盒，常缩写为STB，是视频／音频附属系统，它支持数字模拟视频广播。数字电视机顶盒的工作原理如下：数字电视机顶盒接收数字电视节目，然后处理数据业务和完成多种应用的解析。
机顶盒系统包括： ·数字信号处理器——完成MPEG编码／解码，以及声音／AC3／MPEG音频处理。·射频解调——完成COFDM／QAM／QI?SK解调，前向误差修正，以及混频。·微控制处理器——控制电子系统、网络和用户界面。·内存——存储执行代码和数据／参数。·视频界面——选择由ADC／DAC和DSP解码／编码的视频源。视频前端口和输出级都需要高性能的运算放大器来放大视频信号。·音频接口——通过音频编码和DSP处理使音频数字化，为MPEG／Ac3的需要提供高质量的音频。·用户接口——使用户连接系统网络、控制视频和音频输入／输出源、完成声音／数据通信。·宽带和无线连接——允许交互式电视、游戏、数字音频和视频、IP电话，以及通过ADSI.传输和接收的视频电话、有线调制解调器802.11接口。
第四篇：机电专业英语第2版电子教案Unit 5
Unit 5 Basic Underfeed Mould I.Lead in Information related to the text Do you know what is referred to as underfeed mould? What basic parts does the mould consist of ? And how is each part designed? Do you know the operating sequence when the floating cavity plate and the feed plate separate from each other? Can you describe the cycle of operation for the mould? Maybe you have seen and you are much interested in the mould, of course also interested in these questions.In this unit, you’ll learn the basic underfeed mould and know how they are operated in practice.Now, let’s study new words and phrases together.II.Word Study
1.assembly [ə'sembli] n.装配；集会，集合[ 复数assemblies ]
1）At that point, robots could help a carpenter, or an assembly worker on a production line.基于这一点，机器人可以帮助一个工匠，或一个生产线上的装配工。2）Shall we start with the assembly line? 咱们从装配线开始看好吗？
3）In the end, a mature lean-production line stops much less frequently than a mature mass-production assembly line.最后，一条成熟的精益生产线比一条成熟的大批量生产组装线停工次数少得多了。
2.substantial [səb'stænʃəl] adj.大量的；实质的；内容充实的n.本质；重要材料
1)We need more substantial investment.我们需要更有力的投资。
2)Any substantial technical innovations required the approval of management and a re-engineering of the entire network.任何实质的技术创新都需要管理层的批准，并需要对整个网络进行重构。
3)Thus, the processes used emit substantial amounts of greenhouse gases and have other environmental impacts.因此，整个过程依旧会排放可观的温室气体，对环境造成其他的冲击。3.incorporate [in'kɔ:pəreit] vt.包含，吸收；把……合并adj.合并的；组成公司的 [ 过去式incorporated 过去分词incorporated 现在分词incorporating ] 1)Since it is a composite output, it is easy to incorporate it to the existing system.因为它是合成生产，在现有的系统中合并较容易的。
2)These creatures could incorporate raw meat in their diet and process food more efficiently.这些动物能够在其食物中加上生肉，能更有效地对食物加工。3)You may decide to incorporate your competitive advantage into your mission and/or vision statements.你或许会决定将你的竞争优势融入到公司使命和前景发展中去。4.impetus ['impitəs] n.动力；促进；冲力
1)The writer believes team work provides staff a stronger impetus。团队工作给予成员们更强劲的动力。
2)We would then have to use this to give impetus to the search for peace.我们就必须利用这一点推动对和平的探求。
3)This causes your flight impetus to stop and the gravity habit then pulls you down.这使你的飞行动力停止，重力习惯又把你拉回地面。5.withdraw [wið'drɔ:] vt.撤退；收回；撤消；拉开 vi.撤退；离开 1)When workers retire, they can withdraw money from the plan.当工人们退休了，他们能从计划中收回金钱。
2)Surcharges are deducted from your balance at the same time you withdraw cash from the ATM.在你从自动取款机取钱的同时费用就会从你账户的余额里扣除。3)Russia should withdraw its troops to where they were before the war broke out.俄国应将军队撤回战争爆发之前所驻扎的地区。6.insert [in'sə:t] vt.插入；嵌入 n.插入物
1)I wish to insert an advertisement in your newspaper.我希望在你们的报纸上登一则广告。
2)Insert the source and destination disks, and then click OK.请插入源盘和目标盘，然后单击“确定”。
3)The error described above occurred when trying to insert or update this data at the other server.当试图在其他服务器上插入或更新此数据时，将发生上述描述的错误。7.accommodate [ə'kɔmədeit] vt.容纳；使适应；供应；调解vi.适应；调解 [ 过去式accommodated 过去分词accommodated 现在分词accommodating ] accommodate with 向…供应；提供；以…供应
1)Flood shelters can accommodate 100-300 families.洪灾避难所可以容纳100-300个人家。
2)The runway of this airport is undergoing expansion to accommodate large planes.这个机场的跑道正在扩建以适应大型飞机起落。
3)Iraqi politicians will have to do what they find hardest: accommodate each other.伊拉克的政治家们将不得不面对他们最难做到的事情：容忍对方。
III．Language points 1.The mould consists of three basic parts, namely: the moving half, the floating cavity plate and the feed plate, respectively.译文：这种简单的模具结构如图3-1所示，模具设计和开模顺序将在以下的篇幅中论述。
说明：“consist of ” means “to be made of or formed from something”(由…构成)，e.g.1)All bodies consist of molecules and these of atoms.一切物体都是由分子和原子构成的。
2)They consist of at least two large towers anchored to the ground, a roadway, and a web of steel cables strung between the towers and from each tower to the anchorages at either end.它们至少由两座根植与地面的巨大的塔，一条公路和从两边的塔中发出的在塔间形成的排成一列的网状钢铁缆绳组成。
“namely”: used when you want to give more detail or be more exact about something you have just said.e.g.1)Personally, in an ideal world, I would favour the first set of ideas, namely full privatisation.个人角度来说，在理想情况下，我支持第一种观点，即完全私有化。
2)In fact, Iran halted only the least important component of its nuclear program, namely weaponization.而实际上，伊朗伊朗只是暂停了核项目里最不重要的一部分，也就是武器化。
2.Thus the moving half in this design is identical with the moving half of basic moulds.译文：这种设计与最基本的模具结构中的动模部分相同。说明： “be identical with” means “ be the same with”(与…相同，一致)，e.g.1)The number on the card should be identical with the one on the cheque book.卡上的号码应该和支票簿上的相同。
2)The blog folder on the server, and the wordpress folder on your computer should be identical with regards to the contents.服务器上的blog文件夹和你的电脑上wordpress文件夹，内容应该是一样的。
3.The floating cavity plate, which may be of the integer or insert-bolster design, is located on substantial guide pillars(not shown)fitted in the feed plate.译文：浮动型腔板通过导柱(图中没有示出)固定在定模板上，设计形式可以是整体式，也可以是嵌入式。
分析：“which” introduces a nonfinite attributive clause to modify “floating cavity plate”.“fitted in the feed plate” is a past participle phrases used as attribute to modify “guide pillars”, it has the same function as an attributive clause.说明：“be located on” means “to be in a particular place”(位于，坐落于)e.g.1)This site must be located on the local computer.该站点必须位于本地计算机上。
2)The installation directory must be located on an NTFS drive.安装目录必须位于NTFS驱动器。
4.Guide bushes are fitted into the moving mould plate and the floating cavity plate respectively.译文：导套分别安装在动模板和浮动型腔板上。
说明：“respectively” means “separately, alone, in several”(分别地，各自地)e.g.1)Those labels could be applied respectively to America's and greater China's entire banking systems.这些标签可以分别用于美国的整个银行体系和大中华的整个银行体系。
2)From 2013, the retirement age for public workers will rise to 65 for both men and women, up from about 57 and 52 respectively.从2013年开始，公共部门人员的退休年龄由之前的男性57岁，女性52岁统一延长至男女统一65岁。5.The impressions are filled via the feed system(Figure 3-1(a))and, after a suitable dwell period, the machine platens commence to open.译文：熔体经过浇注系统充满型腔后(如图3-1(a)所示)，经过适当的保压过程，注塑机带动模具开模。
说明：“via” means “through;using”(prep.取道，通过；经由)e.g.1)Send this parcel via air mail.用航空邮寄这个包裹。
2)And via the new investors, Wall Street may enjoy better access to emerging markets.通过这些新股东，华尔街找到了更好的途径进入新兴市场。“commence” means “to begin something”(开始；着手)e.g.1)It is expected the changes will commence in the first quarter of 2010.新的政策变化预计将在2010年的第一季度开始实行。
2)The best of plans must have a solid foundation before execution can commence.最妥善的计划在开始前，必须具有坚实的基础。
6.The sprue puller, being attached to the moving half, is pulled…and the feed plate.译文：安装在动模部分的拉料杆脱离浮动型腔板，……
分析：“being attached to the moving half” is a present participle phrases used as attribute to modify “sprue puller”, it has the same function as an attributive clause.说明：“release” means “make free or public”(释放，发射)e.g.1)Plants also release the gas into the atmosphere.植物也释放这种气体进入大气。
2)Explosions release huge clouds of gas that envelop the surrounding area.爆炸释放出巨大的气体云会要覆盖周围地区。
IV.Translating Skills
增词译法
科技英语具有词义多、长句多、被动句多、词性转换多、非谓语动词多、专业性强，结构严密、逻辑性强等特点。在科技英语翻译实践中，有时若按字面翻译，句子的结构不完善，或句子的含义不明确，或词汇的概念不清晰时，需要增加某些词语，以便更完善、清楚地表达英语句子的内容。
增词译法，是翻译的基本方法之一，就是在译句中增加或补充句子中原本没有或省略掉了的词语，以便更完善、更清楚地表达原意。
一、增加表示时态的概念的词
英语中通常用动词形式变化或加上助动词表示时态，翻译时要刻意用汉语表达出来。
例如：The mechanical ignition system was mechanical and electrical and used no electronics before 1975.1975年之前，机械式点火系统只采用机械装置和电气装置，并不采用电子装置。（‘used’表示过去状态）
二、增加表示数的概念的量词
翻译数词时，常常需要加上量词，如“个”、“只”、“量”、“台”等。此外，还要根据上下文正确判断其复数是“二”还是“多个”。
例如：The distributor has two tasks to perform.分电器有两个任务需要完成。（增加量词“个”）
又如：Chromium improves the properties of steel.铬可改进钢的各种性能。（‘properties’译为“各种”）
三、增加省略的句子成分
英译汉时，有时所有的词汇都相应地译出后，汉语句子的结构显得不完整。这时，应增补缺少的句子成分。
例如：An exact solution demands much calculation.一个精确的解答要求进行很多次计算。（补充谓语“进行”）
又如：Fuses are cheap,other equipment is much more expensive.保险丝很便宜，但其它保险设备却昂贵得多。（在“设备”前补充定语“保险”）
四、增加原文省略的词
英语中常根据语法或语言习惯省略某些重复出现的词语，但用汉语逐词翻译后不能清楚、明确表达原句概念，可补充出来进行解释说明。
例如：The following discussion assumes the teeth gear to be perfectly formed,perfectly smooth,and absolutely rigid.下面的讨论中假定轮齿加工没有误差，轮齿表面完全光滑，轮齿为绝对刚体。（增加重复词语“轮齿”）
五、增加语义连接词语或其他有特殊意义的词语 例如：The best service information in the world is useless if the technician cannot readily retrieve the information.如果技师不会快速地检索住处的话，那么，即使世界上最好的维修信息，也都就没有用了。（增加衔接词语“也都”）
又如： The reliability of semi-conductor devices is very important,especially in space applications.半导体器件的可靠性至关重要,特别是在空间技术应用中尤其如此。（增加“尤其如此”）
V.Key to Exercises of the text I 1.The basic mould consists of three basic parts, namely: the moving half, the floating cavity plate and the feed plate, respectively.2.The moving half consists of the moving mould plate assembly, support blocks, backing plate, ejector assembly and the pin ejection system.3.The desired operating sequence is for the first daylight to occur between the floating cavity plate and the feed plate.This ensures the sprue is pulled from the sprue bush immediately the mould is opened.To achieve this sequence, springs may be incorporated between the feed plate and the floating cavity plate.II.1.T
2.F
3.F
4.T III.1.模具由三个基本部分组成，分别是动模部分、浮动型腔板和定模板。2.在动模板的适当位置钻孔，以便安装限位钉。Key to Exercises of the reading 1.ejector grid
2.the fixed half 3.bar ejection 4.sprue puller
VI.阅读材料参考译文
模具的顶出系统
模具的顶出系统将在以下三个标题中讨论，即：(i)推出支架；(ii)推板装配机构；和(iii)推出方式。
推出支架
推出支架是模具的一部分，用来支撑模板，并为推板的装配和运动提供空间。推出支架通常由动模座板和几块支撑块组成，支撑块安装在动模座板上，且便于加工成型。
推出支架有三种设计形式：(i)同轴的推出支架；
(ii)框状推出支架：
(iii)圆形支架。推板装配机构
推板装配机构也是模具的一部分，用来安装推出零件。推板装配机构安装在推板支撑架内，直接装在模板后面。装配机构由推板、推板固定板和注塑机顶出杆组成。注塑机顶出杆一端带有螺纹，通过螺纹紧固在推板上。在这种结构中，顶出杆的作用不仅是推出零件，而且顶出杆上直径相等的部分通过顶出杆套筒，套筒安装在模具座板上。在更详细讨论模具推出方式之前，我们了解一下推出机构是如何工作的。模具安装在注塑机的移动台板上，台板左侧是注塑机推动杆。推动杆的位置是可以调整的，以适应不同的“推动力”。当移动台板向左移动时，开模，在推动杆的作用下模具推杆运动。整个模具推件装配机构如图5-l(b)所示。动模的其余部分(例如模板和推出支架)继续向左运动，直到模具完全打开(如图5-l(c)所示)。为使推出元件起作用，推板装配板和模板之间必须存在相对运动。
推出方式
对于内部不带有其他形状的塑件，塑件冷却后，其收缩状态取决于塑料熔体的成型过程。例如实芯矩形件，塑件的收缩作用使其脱离型腔壁，因此，可以采用简单的脱模方式(推出塑件)。
然而，若塑件具有内部形状，冷却收缩时塑件将包紧在型芯上，因此，有必要采用一些适当的方式推出塑件。
设计推出机构时有几种方式可供选择，但是，总的说来，选择哪种推出形式取决于塑件的形状。基本的推出方式有以下几种：(i)针状脱模；(ii)推管脱模；(iii)推杆脱模；(iv)推件板脱模；（v)气动脱模；(vi)卸料板脱模。
定模部分的推出机构
尽管推出机构通常安装在模具的动模部分，但这种方式并不总是可行的。考虑到箱形塑件的表面质量，浇口必须设置在塑件内部。这种情况下，型芯和推出系统安装在定模部分，模具具有一定的复杂性。
首先，推出支架和推板装配板安装在定模板后面，这将极大地增加模具高度。因此，熔体从喷嘴射出后要经过较长的距离(才能进入型腔)。然而，为缩短这段长度，浇口套(必须)较深地进入模板内，装配结构如图例，这就必须使用特殊的延伸式喷嘴。
其次，注塑机的定模部分并不提供任何驱动推出系统工作的动力装置，这就意味着动力机构必须与模具设计成一体。
尽管在上面“推出方式”中讨论的所有推出方式都能安装在模具的定模部分，但是在设计时应根据具体情况选择适合的方式。
拉料杆
开模时，流道凝料必然从浇口套中拉出。对于单腔模具，熔体沿着主流道直接进入模具型腔。开模时，塑件脱离型腔，浇道凝料也一同脱出。
对于带有基本浇注系统的多腔模具，每次开模时浇道凝料很可能滞留在浇口套中，必须用手工去除熔体凝料。为避免这种情况，设计时总会考虑安装浇道凝料拉出机构。
普通的拉料方式是利用推杆顶部加工出的凹陷拉料，或者利用主流道入口处的凹陷拉料，该处凹陷与主流道的(锥度)方向相反。熔体进入凹陷后，(冷却)凝固，开模时，(这部分凝料)能够提供足够大的阻力以拉出浇道凝料。
拉料杆有两种基本形式。一种是在冷料井底部加工出空间，这种方式适合在分型面下部使用。另一种是在拉料装置的顶部加工出适当的形状，该方式适合在分型面上部使用。为区分两种基本拉料方式，我们分别用方式A和方式B表示。
第五篇：机电专业英语第2版电子教案Unit 7
Unit 7 The Injection Molding and Machine
I.Lead in
Information related to the text Do you know what is called an injection molding machine? Can you give an example of it? What does it work? In this unit you will learn some the Injection Molding and Machine concept, how it is wide application.Now, let's learn new words and phrases.II.Word Study
1.inject [in'dʒekt]
vt.注射，注入
injection n.注射，投资，注射剂 1）A sterile applicator is used to inject the microchip just under the skin.一个消过毒的涂药器被注射进微型芯片在表皮之下。
2）Major banks around the world are joining forces to inject as much as 180 billion dollars into global money markets.全世界的主要银行都加入了抵制注入180亿美元到全球的经济市场中的行动。
3）Fire ants get their name because when they sting, they inject poison into the skin that causes a feeling of intense burning.Some people suffer life-threatening reactions.火蚁因当他们叮住目标时会将一种能导致灼热感的有毒物质注入皮肤而得名。有些还会有生命危险的反应。
4）There would be no need for injection, since the vaccine would be taken by mouth.通过口服疫苗，我们就不需要注射了。
2.melt [melt] vt.使软化，使融化，使熔化，使感动
1）This element is of proper shape and cross-section to carry rated current continuously and to melt in accordance with a specific time-current characteristic on heavy overload or short circuit.此可熔断元件恰当的形状和横截面使其可连续通过额定电流，而对于严重过负荷或短路，按规定的时间一电流特性而熔断。
2）Either it exposes land, which then warms up;or it forms ponds(or lakes or streams)of meltwater on the surface of the ice, which absorb energy and melt more ice.融冰过程要么导致陆地暴露并且温度升高，要么在冰层表面形成池塘（或湖泊，或溪流），并吸收能量，融化更多的冰。
3）Her money seemed to melt away in Paris.在巴黎她的钱似乎自行消失了。
4）If fast growth and urbanization continue, some overcapacity will melt away.如果高速增长和城市化进程得以持续，部分产能过剩将得到消化。3.powdered ['paudəd] adj.粉状的, 变成粉末的,涂粉的 1）The ground was lightly powdered with snow.地上薄薄地铺了一层雪。
2）If you combine powdered milk and water, you get liquid milk.把奶粉和水合在一起就成了牛奶。
3）Ceramic elements are made by pressing and sintering finely powdered materials.陶瓷元件是将仔细研磨的材料经过加压和烧结制成。
4）The sweet scented orris root, is the powdered root of the Florentine iris, which was grown in ancient Greek and Roman gardens.有香甜味的鸢尾根是佛罗伦萨鸢尾有许多小斑点的根，这种鸢尾长在古希腊和罗马花园里。
4.hopper ['hɔpə] n.斗；单足跳者；跳虫；漏斗 1）Raise hopper feeding inlet size and height.加高投料口尺寸及投料高度。
2）Flexible tube used to convey either powder from hopper to gun or compressed air to gun.把粉末从粉桶输送到喷枪或把压缩空气输送到喷枪的柔性管子。3）Automatic material loading ty using vacuum blower and material hopper with photo electrical material level sensor.配备电眼料斗与送料风机，能自动上料。
4）When the students left the examination room, they jotted down these questions quickly from memory and put them into the fraternity hopper.学生离开考场后，凭记忆迅速将这些问题写下来，然后存入联谊会的议案箱。
5.screw [skru:] vt.旋，拧；压榨；强迫n..螺丝钉；螺旋vi.转动，拧 1）Can you work the screw loose? 你能使这个螺钉松开吗？
2）John must have a screw loose to quit such a good job.约翰辞掉这么好的工作，一定是神经不正常。3）This eyelet is so small that even the smallest screw cannot pass through.这个孔眼太小了，最小的螺丝钉都穿不过去。
4）He is an old screw.You will never be able to make him give out one dollar.他是个老守财奴，你不可能令他交出一元一分。
6.shear [ʃiə] vt.修剪，剪；剥夺 n.切变；修剪；大剪刀 1）In fluids, forces of tension and shear can often be ignored.在流体中，张力和切力通常可以忽略不计。2）How long does it take to shear a sheep? 给一只羊剃毛要花多久时间？
3）Because you already are I this life forever are unable to shear the shed worrying.因为你已是我今生永远无法割舍的牵挂。
4）Textbooks commonly denote shear stresses by the symbol and two subscripts.教科书通常用符号和两个脚标表示剪应力。
7.hydraulic [hai'drɔ:lik] adj.液压的, 水压的, 水力的；水力学的 1）The hydraulic shock damper is commonly used to reduce the vehicular vibration.液压减振器一般用来衰减车辆的振动。2）The paper presents a new structure of honing internal_ hole of hydraulic prop on general lathe.介绍一种在普通车床上珩磨液压支柱内孔的新结构。
3）The Brake system can be divided into two principal parts, hydraulic system and wheel Brake assemblies.制动系统可以分为两个基本部分：液压系统和车轮制动总成。4）Solenoid valve is a basic component in automatic flow control, it is actuator but not limited to hydraulic, pneumatic.电磁阀是用来控制流体的自动化基础元件，属于执行器；并不限于液压，气动。
8.polymerize ['pɔliməraiz] vt.(使)聚合 1）Polymerize together, of two substances.两种物质共同聚合在一起。
2）Of spill or leak: flood with water to polymerize.产品外溅或泄露的措施：用水冲使其聚合。
3）“Polymerize life energy;Cherish being health” is the eternal management idea in the enterprise.“聚合生命能量，呵护人类健康”是我们永恒的经营理念；
4）In this paper, polymerization of maleic anhydride which is difficult to polymerize in normal condition was studied by means of microwave radiation.3
将微波辐射用于一般情况下难以聚合的马来酸酐的聚合，采用家用微波炉进行微波辐射。
III．Language points
1.Injection molding is principally used for the production of the thermoplastic parts, although some progress has been made in developing a method for injection molding some thermosetting materials.译文：尽管注塑成型某些热固性塑料的方法取得了一定进步, 但注塑成型主要(还是)用来生产热塑性塑料制件。
说明： “be used for” 意为“（某物）被用做……”其后接名词、代词或动名词，e.g.1）Either of the lathes may be used for machining the parts.两台车床随便哪一台都可以用来加工这些零件。2）What could whale be used for other than being eaten? 鲸除了可以吃还有其他用途吗?。
3）Falling water may be used for the generation of electricity.高处落下的水可用来发电。
2.The problem of injecting a melted plastic into a mold cavity from a reservoir of melted material has been extremely difficult to solve for thermosetting plastics which cure and harden under such conditions within a few minutes.译文：热固性塑料熔体在很短的时间内就会固化和硬化, 在从料斗向模具型腔注入热固性塑料熔体的过程中, 也会出现这种情况, 这个问题一直非常难以解决。
说明：句中of injecting a melted．．．of melted material是介词短语作后置定语, 修饰the problem ；which cure and harden．．．是定语从句作后置定语, 修饰thermosetting plastics。be difficult to do sth意为做某事有困难，e.g.1）The little child cannot be made to do such a difficult thing.不要让这个小孩子来做如此困难的事情。
2）Life may be difficult to achieve the goal, but I do not care.也许一生也难达到目标，但我并不在乎。
3）No matter how difficult English may be, you should do your best to learn it.无论英语有多么难，你都应该尽你最大的努力来学它。
3.The process consists of feeding a plastic compound in powdered or granular form from a hopper through metering and melting stages and then injecting it into a mold.译文：注塑成型工艺包括：首先把料斗中的粉状或粒状的塑料混合物
依次输送到计量区和熔融区, 然后再注射到模具型腔中。
说明：“consist of” 意为“包括，由……组成”，e.g.1）All bodies consist of molecules and these of atoms.一切物体都是由分子和原子构成的。
2）About half of China's exports consist of goods that have been assembled from imported components.中国大约一半的出口由来自进口零部件组装而成的商品构成。3）What did your work consist of exactly? 你的工作具体都做些什么？
4.Injection-molding machines can be arranged for manual operation, automatic single-cycle operation, and full automatic operation.译文：注塑机分为手动、半自动及全自动操作。
说明：“be arranged for” 意为“被安排”，e.g.1）He arranged for the meeting to be put off for a week.他安排把会议延后一周召开。
2）All these need to be arranged and paid for in advance.所有这些都需要提前安排并付清款项。
3）We have arranged for her to be operated on by the best doctor.我们已经安排好让最好的医生给她做手术。
5.As the chamber in front of the screw becomes filled, it forces the screw back, tripping a limit switch that activates a hydraulic cylinder that forces the screw forward and injects the fluid plastic into the closed mold.译文：当熔体充满螺杆前部区域时, 螺杆在熔体压力作用下后退, 触动限位开关使油缸工作, 在液压力作用下推动螺杆向前运动, 将熔融塑料注射到闭合的模具型腔中。
说明：句中as引导时间状语从句，it forces the screw back为主句，tripping．．．是分词短语作伴随情况的状语。that activates ．．．为定语从句修饰a limit switch，第2个that 引导的定语从句修饰a hydraulic cylinder。“in front of” 意为“在……(外面的)前面”，e.g.1）Mr.Lin moved in front of the door.林老师走到门的前面。
2）Is Lingling behind Mary or in front of her? 玲玲在玛丽后面还是在她前面?。
3）He paraded in front of the mirror in his new uniform.他穿着新制服神气活现地照镜子。
6.A rule-of-thumb can be used to determine the tonnage required for a particular job.译文：通常靠经验来决定塑件所需要的锁模力总吨数
说明：“be used to” 意为“习惯于”，e.g.1）And the sensor could be used to help people on earth.这种传感器也可以帮助地球上的人们。
2）Computer methods may then be used to advantage.采用计算机方法是有益的。
3）Much more money will be used to prevent pollution.更多的钱，将被用于防治污染。
7.It is based on two tons of clamp force per square inch of projected area.If the flow pattern is difficult and the parts are thin, this may have to go to three or four tons.译文：一般在塑件投影面积上每平方英寸需要作用两吨锁模力。如果熔体流动困难或塑件较薄, 锁模力应提高到3～4吨。
说明：“is based on” 意为“根据，以…为基础；建立在…基础上”，e.g.1）His argument is based on fact.他的论据以事实为基础。
2）The book is based on an actual case.这书是根据一个实际案例写的。
3）Father Christmas is based on a real person in history.圣诞老人源于历史上一个真实的人物。
IV.Translating Skills
科技英语词汇的构成Ⅰ
科技英语(English for Science and Technology，简称EST)可以泛指一切论及或谈及科学和技术的书面语和口语。科技英语词汇概括起来主要有 5个特点：（1）科技英语词汇多源于希腊语和拉丁语；（2）词义专一；（3）前后缀出现频率高；（4）专业词汇出现的频率低；（5）广泛使用缩略词。科技英语词汇可以分为三类：科技词汇、半科技词汇和非科技词汇。
1．科技词汇（technical terms）
科技英语有许多专门的术语，只在某一特定的科技领域来用。许多情况下，虽然同为科学家，这个领域的科学家并不明白另一领域的词汇，比如物理学家就可能不明白生物学领域的专业术语。且由于科学技术发展，科技术语(词汇)也日益增多。我们在阅读或翻译一些科技方面文章时，一定要了解该领域的专业术语，否则可能就会云里雾里不知所云。
例如：化学领域中的isotope（同位素）；物理领域的photon(光子)；以及生物领域的chromosome(染色体)等等，都是科技词汇。半科技词汇（semi-technical terms）
半科技词汇指的是那些不同于生活中的语言词汇，而且在不同领域又有不同的含义的词汇，也称通用科技术语。
例如 orbit, 在医学上指的是“眼眶”，而在物理学上则是“轨道”；很普通的词web(网)、net(网)、site(站点)在计算机科学中都成了与原词仍然关联的专业词汇，如website(网址、网站)、internet(互联网)；Mouse(老鼠)、memory(记忆)、read(阅读)在计算机科学中是“鼠标”、“内存”和“读取”。非科技词汇（non-technical terms）
非科技词汇指经常用于科学技术领域，在日常生活当中则不常用的词汇，在修辞学上指的是那些正式用语（learned and formal words）。因为科技英语是一种描述各种自然现象、客观事实的发生过程和特性的语言，所以科技英语的文章不用那些日常生活中的常用词汇（common words）。
例如，日常生活中我们用give、have，而科技英语中我们用posses；日常生活中用refer to，科技英语中用allude to，日常生活中用mad，科技英语中用 insane 等等。
V.Key to Exercises of the text.Ⅰ.1.b
2.d
3.a
4.e
5.c Ⅱ.1.The advantage of injection molding are:(1)A high molding speed adapted for mass production is possible.(2)There is a wide choice of thermoplastic materials providing a variety of useful properties.(3)It is possible to mold threads, undercuts, side holes, and large thin sections.2.The principle of injection molding is quite similar to that of diecasting.The process consists of feeding a plastic compound in powdered or granular form from a hopper through metering and melting stages and then injecting it into a mold.After a brief cooling period, the mold is opened and the solidified part ejected.Ⅲ.1．In order to harden and eject thermoplastic parts from the mold，cooling would be necessary.2．This type of mold is widely used because it is comparatively easy to construct and it controls thickness and density within close limits.3．注射成型过程中最重要的问题无疑是注射模具的正确设计，因为成型车间对注射件的影响很小，即便有，也是对机器设备的结构有影响。
Key to Exercises of the reading
1．一般说来，无机物比有机物有更好的抗热性。2．此外，就是要在各种制造方法方面具有坚实的理论基础知识和实践经验。
3．Many products, such as those made from colored plastics or other special materials, are saleable because of appearance.VI.阅读材料参考译文
注塑机组成部件
注塑机将粒状热塑性塑料材料通过熔融、注射、保压和冷却这样的循环过程转化为最终的模塑制品。典型的注塑机的主要组成部件如图7-2所示
注射机构
注射机构包括料斗、往复式螺杆、料筒和注射用喷嘴, 如图7-3所示。该部分在喂料、压缩、排气、熔融、注射和保压阶段起到承接和运送物料的作用。
(1)料斗
热塑性物料以小颗粒状供给成型, 注塑机料斗要盛装这些粒料, 物料以重力形式通过加料斗颈部喂到料筒和螺杆中。
(2)料筒
如图7-3所示, 注塑机料筒承载往复式螺杆并由电加热圈加热。
(3)往复式螺杆
往复式螺杆可用来压缩、熔融和输送物料, 由三段组成(如下所述)：加料段、压缩段(过渡段)和计量段(图7-4)。
当螺杆外径不变时, 往复式螺杆的螺纹深度自加料段到计量段开始处逐渐变浅, 物料被压向料筒内径处并产生黏性剪切热, 这些剪切热对于物料的熔融很重要。料筒外的加热圈能一起保证物料处于熔融状态。通常注塑机有三段或更多的加热圈, 各部分温度设定并不相同。
(4)喷嘴
喷嘴(图7-5)连接料筒与模具上的主流道衬套并且在料筒和模具之间形成密封。喷嘴温度应设为物料的熔融温度或稍低, 这取决于材料供应商的推荐值。当料筒处在满料等待注射状态时, 喷嘴头部应牢牢压在带有定位环的主流道衬套的凹坑面上, 并保证密封。当清洗料筒时, 料筒后退与浇道套分离, 这样清洗料才能从喷嘴处自由落下来。
模具系统
模具部分包括拉杆、动模固定板、定模固定板以及开设有型腔、主流道、分流道、顶出杆和冷却水道的成型模具, 如图7-6所示。模具其实是
一个热交换系统, 热塑性熔体在其中固化成为型腔给定尺寸和形状的制品。
模具包括凸模和凹模, 常用模具钢制造, 模具机构可通过型腔成型和顶出制品。定模固定板在注塑机料筒一侧, 并通过导杆与动模固定板连接。凹模模板一般固定在定模固定板上并承接喷嘴, 凸模板安装在活动模板上由拉杆导向随之一起移动。凹模模板有时也可固定到动模固定板上, 而凸模板和液压顶出机构固定到定模固定板上。
液压系统
注塑机上的液压机构可提供开、合模的动力和锁模力, 旋转和驱动往复式螺杆、推动顶杆及带动型芯移动。这需要一系列的液压元件完成, 如泵、阀、液压马达、管接头、管道和蓄能器等。
控制机构
控制机构可保证设备连续重复工作, 能监测和控制成型参数, 如温度、压力、注射速度、螺杆速度和位置、液压状态。过程控制对于制品最终质量和成型的经济性很重要, 可以是简单的开／关控制, 也可以是非常复杂的基于微处理器的闭环控制系统来完成。
锁模机构
锁模机构用于开启和闭合模具, 支撑和移动模具零部件, 产生足够的推力防止模具开启。锁模力可通过机械肘杆式机构、液压式机构或机械一液压组合式机构来实现。
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