作者：于海祥,冯艳宏,张帆
出版社：中国铁道出版社有限公司
格式: AZW3, DOCX, EPUB, MOBI, PDF, TXT
机电专业英语试读：
前言
FOREWORD本书根据技能型紧缺人才培养培训工程机电一体化专业的教改方案要求，结合机电一体化专业课程教学和英语基础课程教学而编写。
本书是高等职业院校基础英语的后续教材。本书的教学目标是使学生熟悉机电一体化设备操作与维护中常见的英文，为学生今后阅读相关的英文说明书及资料，掌握机电一体化设备的操作与维护及进一步学习打下良好的英语基础。
本书包括机械技术基础、控制技术基础和机电一体化设备应用3个模块，共有13个任务。模块1主要介绍机械工程、机械制造、数控编程和公差及测量等机械技术基础知识；模块2主要介绍电气控制、液压控制、气动控制和PLC控制等控制技术基础知识；模块3主要介绍数控机床、数控电加工机床、工业机器人、自动化生产线和机电设备的安全与维护技术等机电一体化设备应用技术。
本书主要特点如下：（1）按照学生认知规律创设功能模块，任务取材遵循“专业、实用、易学”的原则，贴近专业生产实际。（2）任务内容选取紧密结合专业课教学内容，起到巩固专业课教学内容的作用。（3）根据任务内容，选择恰当的图片（课文翻译部分只保留有翻译内容的图片），图文并茂，更直观，更有助于学生理解教学内容。
本书由天津中德应用技术大学于海祥，天津冶金职业技术学院冯艳宏、张帆任主编；郑州铁路职业技术学院刘源、天津中德应用技术大学赵歆、天津冶金职业技术学院李焱任副主编。具体编写分工如下：于海祥编写了模块1的任务1、任务2和模块3的任务4；冯艳宏编写了模块1的任务3、任务4，模块3的任务3、任务5；张帆编写了模块2的任务2～任务4；刘源编写了模块3的任务1；赵歆编写了模块2的任务1；李焱编写了模块3的任务2。全书由于海祥统稿。本书由天津冶金职业技术学院李桂云教授主审并对本书提出了许多宝贵意见，在此一并表示感谢！
本书适合作为高等职业院校机电一体化技术、数控技术、机械制造与自动化、工业机器人等专业的教材，也可作为相关岗位培训的参考书。
由于编者的水平有限，加之时间仓促，书中难免存在各种疏漏和不足之处，希望读者提出宝贵意见和建议。编者2017年3月Module 1Foundation of Mechanical TechnologyTask 1Mechanical EngineeringPart AText1.1.1 Drawing
1.Engineering drawing
Typical drawings in machine manufacturing are classified as part drawings and assembly drawings.（1）Part drawings（Fig.1-1-1）Fig.1-1-1 Part drawings
Part drawings are frequently used as instructing for manufacture and inspecting for the parts.An integrated part drawing should include a set of drawings，overall dimensions，necessary technical requirements and full contents of title block.
①A set of drawings：some representation can be given to properly show the internal and external shape of the part.
②Overall dimensions：specifying the requirements for manufacture and inspection of the integrity.
③Necessary technical requirements：codes，symbols and notes are used to describe the essential technical requirements in the process of manufacture，inspection and assembly，such as surface roughness，tolerance，heat treatment，case treatment and the like.
④Full contents of title block：including the part name，materials，drawing number，scale and signature of responsible individual.（2）Assembly drawings（Fig.1-1-2）
Assembly drawings are used in explaining machines or components.In mechanical design，part drawings are usually related to the assembly drawing which indicates the working principle and structure of a machine or component.In the process of machine manufacturing，the drawings are to allow machining of the metal based on the part drawing and assembling to create a unit or a machine according to the assembly drawing.Fig.1-1-2 Assembly drawings
2.Representation of machine elements
Mechanical drawings in national standards are restricted to those which specify the view，sectional view and broken sectional view to represent the structures and shapes.
Views are projection drawings of the object.Typical views include basic views，directional views，partial views and oblique views.Basic views include upward view，front view，vertical view，right view，left view and back view，as shown in Fig.1-1-3.The number of views is always six，four and three，four is the typical views.
Sectional views（Fig.1-1-4）are used to show the internal structure of the object with a dash line.When parts have complex internal geometries，knowing the interior is as important as knowing the exterior，you can use sectioning technique to “cut sections” across the object to show internal details.We divide sectional views into full sectional views，half sectional views and partial sectional views.
Broken sectional views（Fig.1-1-5）are supposed to be sectional plane at a point somewhere on the machine element drawn only section graphics.We divide them into removed broken sectional view and superposition sectional view.Fig.1-1-3 Basic viewsFig.1-1-4 Sectional views
For expressing the structure and size of a component distinctly，we put a component into a three-plane projection system，and acquire the three-dimensional drawing in the three projection plane.The basic principle is indicated as equal length in the front view and vertical view，equal height in the front view and left view，equal width in the vertical view and left view.
The axonometric drawing is used for complementing the outline of the body.There are two kinds of axonometric drawings：positive isometric and oblique two.Fig.1-1-5 Broken sectional views1.1.2 Metals and It’s Properties
1.Metals
Metals are divided into two general groups：ferrous metals and nonferrous metals.The major types of ferrous metals are cast iron，carbon steels，alloy steels and tool steels.
The three primary types of cast iron are gray cast iron，white cast iron，and malleable cast iron.Gray cast iron is primarily used for cast frames，automobile engine blocks，hand-wheel and cast housings.White cast iron is hard and wear resistant and is used for parts such as train wheels.Malleable cast iron is a tough material used for tools such as pipes and wrenches.Generally，cast irons have very good compressive strength，corrosion resistance，and good machine-ability.The main disadvantage of cast iron is its natural brittleness.
The three principal types of carbon steel used in industry are low，medium，and high carbon steel.The percentage of carbon is the most important factor in determining the mechanical properties of each type of carbon steel.Low carbon contains between 0.05％ and 0.30％ carbon and is primarily used for parts that do not require great strength，such as chains，bolts，nuts，and pipes.Containing between 0.30％ and 0.50％ carbon，medium carbon steel is used for part that required great strength than is possible with low carbon steel，such as gears，crankshafts，machine parts and axles.Containing between 0.50％ and 1.70％ carbon，high carbon steel is used for parts that require hardness and strength，such as files，knives，drills，razors，and woodworking tools.
Alloy steels are basically carbon steels with elements added to modify of change the mechanical properties of the steel.
Tool steels are a special grade of alloy steels used for making a wide variety of tools.
Nonferrous metals are those metals whose major element is not iron.As compared to ferrous metals，the list of nonferrous metals is，of course，long and complex.The major families of nonferrous metals，such as aluminum and aluminum alloys，copper and copper alloys，magnesium and magnesium alloys，titanium and titanium alloys.
2.Properties of metals
The properties of metals are the characteristics that determine how the metal will react under varying conditions.The two principal types of properties are physical and mechanical.Physical properties are those fixed properties that are determined naturally and cannot be changer，such as weight，mass，color，and specific gravity.Mechanical properties，on the other hand，are those properties of metal that can be changed or modified to meet a particular need，such as strength，hardness，wear resistance，toughness，plasticity，and brittleness.（1）Strength
Strength is a property of metal that allows it to resist permanent change in shape when loads are applied.There are four types or forms of strength you should know are：tensile strength，shear strength，compressive strength，and ultimate strength.（2）Hardness
Hardness is the ability of a metal to resist indentation or penetration.Several different methods are used to measure the hardness of a metal；however，the two primary methods，or test，used by industry are the Brinell and Rockwell hardness tests.（3）Wear resistance
Wear resistance is the ability of a metal to resist abrasion.In most cases，the harder the metal，the better it resists wear.（4）Toughness
Toughness is the ability of a metal to resist，or absorb，sudden shocks of loads without breaking.（5）Plasticity
Plasticity is the ability of a metal to be extensively deformed without fracture or rupture.（6）Brittleness
Brittleness is the property of a metal that causes it to fracture rather than deform when loads are applied.Brittleness is the opposite of plasticity.1.1.3 Heat Treatment of Metals
Heat treatment is a process of controlled heating and cooling of a metal to achieve a characteristics change in the properties.Heat treatment curve is shown as Fig.1-1-6.The five common heat-treating operations performed on steels are annealing，normalizing，hardening，tempering，and case hardening.Most nonferrous metals can be annealed，and some are harden-able by heat treatment.However，nonferrous metals are not normalized，tempered，or case hardened.
Annealing is a process used to soften metals that is generally performed on hardened parts that，for some reason，must be machined.Purposes of annealing：remove hardness；increase malleability；increase ductility；improve machine-ability；refine grain structure.
Normalizing is a process used to reduce the internal stresses in a metal caused by machining or forming.Purposes of normalizing：relieve stresses；produce normal grain size and structure；place steels in the best condition for machining；lessen distortion in heat treating.Fig.1-1-6 Heat treatment curve
Hardening is the process of increasing the strength，hardness，and wear resistance of a metal.Purposes of hardening：increase hardness，strength and wear resistance.
Tempering relieves some of the stressed caused by rapid cooling in the hardening process.Purposes of tempering：reduce hardness to desired level；increase shock resistance and impact strength；reduce brittleness；relieve stresses caused by rapid cooling.
Case hardening is a process of producing a hard case，or shell，around a low carbon steel part by adding carbon to its surface.This process is well suited for parts that need a hard，wear-resistance surface and a tough inner core.Gears，sprockets are typical example of parts that are case hardened.1.1.4 Machine Elements
1.Machine and parts
However simply，any machine is a combination of individual components generally referred to as machine elements or parts.Thus，if a machine is completely dismantled，a collection of simple parts such as nuts，bolts，springs，gears，cams and shafts，etc.—the building block of all machinery.
The most common example of a machine element is a gear.Gears are designed to transfer rotary motion from one shaft to another.The speed of the motion is increased or decreased by changing the size of the drive gear and the driven gear.
2.Name of different gear parts（Fig.1-1-7）（1）Number of teeth
The total average number of gear teeth on the gear circumference is called the number of teeth，which is symbolized as Z.（2）Addendum circle，dedendum circle
The space between the adjacent two teeth is called the keywall.The circle over the bottom of all keywalls are called dedendum fcircle，whose radius is symbolized as r .The circle over the top of all gear teeth are called addendum circle，whose radius is symbolized as ar .The addendum circle of the external gear is bigger than its dedendum circle，the addendum circle of the internal wheel is smaller than its dedendum circle.Fig.1-1-7 Name of different gear parts（3）Reference circle
To design or manufacture，a circle is set artificially.The modulus of the circle is a standard value.Also the pressure angle is a standard value.The circle is called the reference circle.（4）Tooth addendum，tooth dedendum，whole depth
The radial distance between the reference circle and the addendum circle is called the tooth addendum，which is symbolized aas h .
The radial distance between the reference circle and the dedendum circle is called the tooth dedendum，which is symbolized fas h .
The radial distance between the addendum circle and the dedendum circle is called the whole depth，which is symbolized as h.
3.Gear types and applications
There are several kinds of gears used in modern machinery.Some of those are spur gears，helical gears，gear racks，bevel gears，worm and worm wheel.
Spur gears（Fig.1-1-8）are the most widely used style of gears and are used to transmit rotary motion between parallel shafts，while maintaining uniform speed and torque.The involute tooth form，being the simplest to generate，permits high manufacturing tolerances to be attained.Fig.1-1-8 Spur gears
Helical gears（Fig.1-1-9）are similar to spur gears with the exception that the teeth are cut at an angle to the axis of the shaft—the helix angle.The helix cut creates a wider contact area enabling higher strengths and torques to be achieved.
Bevel gears（Fig.1-1-10）are used solely to transmit rotary motion between intersecting shafts.Fig.1-1-9 Helical gearsFig.1-1-10 Bevel gearsNew Words and Phrases
roughness [rʌfnəs] n.粗糙，粗糙的地方
tolerance [ˈtɒlərəns] n.公差，限度
sectional [ˈsekʃənl] adj.断面的，局部的，部分（地区）的
oblique [əˈbliːk] adj.斜，倾斜的
gray [greɪ] adj.灰色的，灰白头发的
malleable [ˈmæliəbl] adj.可锻造的，有延展性的，韧性的
razor [ˈreɪzə（r）] n.剃刀，刮面刀
magnesium [mægˈniːziəm] n.[化]镁（金属元素）
titanium [tɪˈteɪniəm] n.[化]钛
characteristic [ˌkærəktə'rɪstɪk] n.性质，特性，特征，特色
tensile [ˈtensaɪl] adj.拉力的，张力的，可伸展的，可拉长的
shear [ʃɪə（r）] vi.剪切，修剪，穿越，[力]切变
ultimate [ˈʌltɪmət] adj.极限的，最后的，最大的，首要的
brinell [brinel] n.（布氏）压痕
abrasion [əˈbreɪʒn] n.磨损，擦伤处，磨蚀
fracture [ˈfræktʃə（r）] n.破裂，断裂
rupture [ˈrʌptʃə（r）] n.断裂，破裂
annealing [əˈniːlɪŋ] v.退火，退火（anneal的现在分词）
normalizing [ˈnɔ：məlaɪzɪŋ] n.正火
tempering [ˈtempərɪŋ] v.回火，钢化
malleability [ˌmælɪəˈbɪləti] n.有延展性，柔韧性，柔顺
distortion [dɪˈstɔːʃn] n.扭曲，变形，失真，畸变
dedendum [dɪˈdendəm] n.齿根，齿根高
addendum [əˈdendəm] n.附录，[机]（齿轮的）齿顶（高）
engineering drawing 工程图纸
assembly drawing 装配图
partial view 局部视图
oblique view 斜视图
cast iron 铸铁
wear resistance 耐磨性
nonferrous metal 有色金属
addendum circle 齿顶圆
dedendum circle 齿根圆
spur gears 直齿圆柱齿轮
helical gears 斜齿轮Exercises
Ⅰ.Match column A with column B.
Ⅱ.Mark the following statements with T（true）or F（false）.（ ）1.Directional views include full sectional views，half sectional views and partial sectional views.（ ）2.The axonometric drawing is used for complementing the outline of the body.（ ）3.Metals are divided into three general groups：gray cast iron，white cast iron，and malleable cast iron.（ ）4.Brittleness is the opposite of plasticity.（ ）5.Tempering relieves some of the stressed caused by rapid cooling in the hardening process.（ ）6.The addendum circle of the external gear is smaller than its dedendum circle.
Ⅲ.Answer the following questions briefly according to the text.
1.Which two kinds are typical drawings in machine manufacturing divided into？
2.What is the application of malleable cast iron？
3.What is the carbon content of medium carbon steel？
4.What’s definition of the strength？
5.What is the function of the normalizing？Part BReading Material Annealing Types
Annealing consists of heating steel slightly above its critical range and cooling very slowly.Annealing relieves internal stresses and strain caused by previous heat treatment，machining，or other cold working processes.The type of steel governs the temperature to which the steel is heated for the annealing process.The purpose for which annealing is being done also governs the annealing temperature.
There three types of annealing processes used in industry are full annealing，process annealing，and spheroidizing.
Full annealing is used to produce maximum softness in steel.Machinability is improved.Internal stresses are relieved.Process annealing is also called stress relieving.It is used for relieving internal stresses that have occurred during cold-working or machining processes.Spheroidizing is used to produce a special kind of grain structure that is relatively soft and machine-able.This processes generally used to improve the machine-ability.Task 2Machinery ManufacturingPart AText1.2.1 Metal Cutting Technology
The six basic techniques of machining metal include turning，milling，planning，grinding，drilling and boring.
Turning is type of metal processing operation where a cutting tool is used to remove the unwanted material to produce a desired product，and is generally performed on lathe.In turning process，the rotation of spindle is the main movement，and the turning tool’s move is the feed movement.Horizontal lathe is shown as Fig.1-2-1.
After lathes，milling machines are the most widely used for manufacturing applications.Vertical and horizontal milling machine is shown as Fig.1-2-2.Milling consists of machining a piece of metal by bringing it into contact with a rotating cutting tool which has multiple cutting-edges.There are many types of milling machines designed for various kinds of work.Some of the shapes produced by milling machines are extremely simple，like the slots and flat surfaces produced by circular saws.Other shapes are more complex and may consist of a variety of combinations of flat and curved surfaces depending on the shape given to the cutting-edges of the tool and on the travel path of the tool.Fig.1-2-1 Horizontal latheFg.1-2-2 Vertical and horizontal milling machine
Planning metal with a machine tool is a process similar to planning wood with a hand plane.The essential difference lies in the fact that the cutting tool remains in a fixed position while the workpiece is moved back and forth beneath.Planners are usually used for processing large workpiece.A shaper（Fig.1-2-3）differs from a planer in that the workpiece is held stationary and the cutting tool travels back and forth.
Grinding machining is important processing technology in mechanical manufacturing.Grinding tool is a rotating abrasive wheel.The abrasive wheel simulates a milling cutter with a large number of miniature cutting edges.The process is often used for the final finishing process to obtain high accuracy dimensions and better surface finish of a part that has been heat-treated to make it very hard.That is because grinding can correct distortion that may have resulted from heat treatment.Grinding can be performed on plat，cylindrical and internal surface by employing specialized machining tools on grinding machine.In recent years，grinding has also found increased application in heavy-duty metal removal operations.Universal grinder is shown as Fig.1-2-4.Fig.1-2-3 ShaperFig.1-2-4 Universal grinder
Drilling involves producing through or blind holes in a solid metal by a cutting tool，which rotates around its axis，against the workpiece.Radial drilling machine is shown as Fig.1-2-5.Drilling operation can be carried out either by hand drill or by drilling machine.Usually，the tool rotates around its spindle while the workpiece is fixed firmly in the latter.Drilling consists of cutting a round hole by means of a rotating drill.The drill can have either one or more cutting edges and corresponding flutes which can be straight or helical.The function of flutes is to provide outlet passages for the chips generated during the drilling operation and also to allow lubricant and coolant to reach cutting edges and the surface being machined.The most common used drills in production are twist drill，center drill，gun drill and spade drill.
Boring，on the other hand，involves the finishing of a hole already drilled or cored by means of rotating，offset，single-point tool.On some boring machines，the tool is stationary and the workpiece revolves，on others，the reverse is true.Boring machine is shown as Fig.1-2-6.Fig.1-2-5 Radial drilling machineFig.1-2-6 Boring machine1.2.2 Cutting Tool
1.Cutting tool materials and property
Cutting tools properties include high hardness and the ability to retain it even at the elevated-temperatures generated during cutting.They also include toughness，abrasion resistance，and the ability to withstand high bearing pressures.A cutting material is selected to suit the cutting conditions，such as the workpiece material，cutting speed，production tare，coolants used and so on.The commonly used cutting tool materials are plain carbon steel，alloy steel，high-speed steel，cemented carbides，diamond，etc.
2.Common tools of turning
Turning operations use one cutting edge at a time.The commonly used turning tools are as follows：external turning tool [Fig.1-2-7（a）]，groove tool [Fig.1-2-7（b）]，thread tool[Fig.1-2-7（c）]，internal turning tools [Fig.1-2-7（d）]，twist drill [Fig.1-2-7（e）] and center drill[Fig.1-2-7（f）]，etc.Fig.1-2-7 Turning tools
External turning tool is used for turning cylinder，taper and facing surface.Groove tool is used in parting the workpiece or cut off the workpiece.Thread tools is used to cut a standard 60degree thread.Internal turning tool is used in a boring operation.Center drill is used to provide positioning for drilling operation.
3.Common cutters of milling
The face milling cutter is used to milling of the upper surface [Fig.1-2-8（a）]；keyway cutters are used to machine contour [Fig.1-2-8（b）]，holes drilled with the center drill[Fig.1-2-8（c）]，twist drill [Fig.1-2-8（d）] and reamer [Fig.1-2-8（e）].Fig.1-2-8 Milling cuttersFig.1-2-8 Milling cutters（continued）
4.Geometry of cutting tool
The cutting part of cutting tool includes a face for passing chips and a flank directed to the workpiece.The intersecting face and flank form a cutting edge.The tool performance depends on its material and angles which mainly include：nose angle，rake angle，relief angle and cutting edge angle.
Rake angle decides the tartness degree of tool，the larger of the
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