飞行器专业英语复习提要.doc

飞行器专业英语复习重点提要：（仅供参考）

考试题型：1.词汇互译，15分；2甸中词汇翻译,25分;3.英文段落翻译,40?45分;4.句了汉译英，15?20分。

内容要点：

上册：

UNIT 1

Lesson 1:

词汇：

工程材料，分类，金属，聚合物（高分子），陶瓷，复合材料，有色金属，黑色金属，韧度，环氧树脂……

段落：

关于T-程材料分类，如：第一页第三段,fourgroups ............ ,第二页的ferrous metals .......... Lesson 2:

词汇：

拉力，压力，刚性，应力，应变，拉伸强度，屈服强度，抗扭强度，疲劳强度，硬度…… 段落：

如：第10 页第一段，the properties of a ...... ,stress and strain, stress is defined ....... , Strain, of unit ....... , 11 页第4, 5 两小段，the stress-strain diagram ...........

UNIT 2

Casting, forging, welding, gas welding, laser welding, explosion welding ......

Lesson 8:

词汇：淬火，冋火，退火，铁素体，马氏体，珠光体……

53 页第一段，Heat treatment ......... , hardening is a process of ........

UNIT 3

bearing, gear,

UNIT 4

Hydraulic, valve

Lesson 14:

词汇：

机床，车床，卧式车床，铳床，磨床，创床，主轴箱，刀架，尾廉，丝杠，转塔车床，仿形铳床……

下册：

Lesson 4 Application of Electronic Instrument

Introduction下面的第二段，电子仪器测量系统各部分组成介绍的段落，包括Transducer, power supply, signal conditioner ...

Open-loop, close-loop

Lesson 12 Computer Aided Manufacturing

段落：

An important feature of CAD/CAM in machining operations is its ability to describe tool paths in operations such as NC turning , milling , and drilling. The programmer provides instructions (programs) to the CAD/CAM system, which automatically determines and optimizes the tool path.The engineer of technician can display and visually check the tool path for possible tool collisions w让h clamps,fixtures,or other interferences.The tool path can be modified at any time to accommodate other part shapes to be machined.CAD/CAM systems are also capable of coding and classifying parts into groups that have similar shapes,using alphanumeric coding.

Numerical control(NC) is a method ofc ontrolling the movements of machine comp onents by directly inserting coded instructions in the form of numerical datafnumbers and letters) into the system.The system automatically interprets these data and converts them to output signals.These signals,in turn,control various machine components,such as turning spindles on and off,changing tools,moving the workpiece or the tools along specific paths.and turning cutting fluids on and off.

An NC machine can be con trolled through two types of circuits:ope n-loop and closed-loop.In the open-loop system,the signals are given to the servomotor by the processor,but the movements and final destinations of the worktable are not checked for accuracy.The closed-loop system is equipped with various transducers,sensors,and counters that measure the position of the table accurately.Through feedback control,the position of the work table is compared against the signal.Table movements terminate when the proper coordinates are reached.The closed-loop system is more complicated and more expensive than the open-loop syste m.

Positioning accuracy in NC machines is defined by how accurately the machine can be positioned to a certain coordinate system.An NC machine usually has a positioning accuracy of at least ±3 u m.Repeatabi 1 ity,defined as the closeness of agreement of repeated position movements under the same operating conditions of the machine,is usually around ±8 U m.Resolution,defined as the smallest in creme nt of mot io n of the mach ine compone nts,is usually about2.5 M m.

The stiffness of the machine tool and backlash in its gear drives and leadscrews are important for accuracy.Backlash can be eliminated with special backlash take-up circuits,whereby the tool always approaches a particular position on workpiece from the same direction,as should be done in traditional machining operations.Rapid response to command signals requires that friction and inertia be minimized,for example,by reducing the mass of moving components of the machine.

Industrial Robots

Also known as the controller, the control system is the communications and informat i on processing system that gives comma nds for the movements of the robot. It is the brain of the robot and stores data to initiate and terminate the movements of the manipulator. It interfaces with computers and other equipment, such as manufacturing cells or assembly systems? Feedback devices, such as transducers, are an important part of the control system.

Application and Selection of Robot

Major application of industrial robots inelude the following:

Material handing, loading, unloading, and transferring workpieces in mmwfacturing operations

Spot welding automobile and truck bodies, producing welds of good quality. Robots perform other similar operations, such as arc welding, arc cutting and riveting Machining operations, such as deburring , grinding, and polishing , with appropriate tools attached to their end effectors

Applying adhesives and sealant, as in the automobile frame

Spray painting-particularly of complex shapes-and cleaning operations

Automated assembly

Inspection and gauging in various stages of manufacture