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«FAMOUS PEOPLE OF SCIENCE AND ENGINEERING»
Sikorsky Igor Ivanovich was a well-known aircraft engineer and manufacturer.
Sikorsky was born in 1889 in Kiev, in the Ukraine, and got his education at the naval college in St. Petersburg, and later in Kiev and Paris. He was the first to make experiments in helicopter design. In 1913 he designed, built, and flew the first successful aeroplane. Later he built military aircrafts for Russia and France.
In 1919 Sikorsky moved to the United States and later helped to organize an aircraft company that produced a series of multiengine flying boats for commercial service. Sikorsky became an American citizen in 1928. In the late 1930s he returned to developing helicopters and produced the first successful helicopter in the west. Helicopters designed by Sikorsky were used mostly by the US Army Air Forces during World War II. He died in 1972 at the age of 83.
Tupolev Andrey Nikolayevich, famous aircraft designer, was born in 1888. He graduated from the Moscow Higher Technical School, where he designed the first Russian wind tunnel. He helped to found the Central Aerohydrodynamics Institute in 1918 and later worked as the head of its design bureau. During his career he directed the design of more than 100 military and commercial aircraft, including the TU-2 and TU-4 bombers used in the World War II. In 1955 he designed the TU-104, the first passenger jet airliner. His TU-144 supersonic jet liner began its commercial passenger flights in 1977.
UNIT 4
MACHINE-TOOLS
I. Text A: «Machine-tools», Text B: «Lathe»,
Text C: «Milling, boring, drilling machines. Shapers and Planers», Text D: «Dies»
II. Famous people of science and technology: George Stephenson, Robert Slephenson.
Text A: «MACHINE-TOOIS»
Machine-tools are used to shape metals and other materials. The material to be shaped is called the workpiece. Most machine-tools are now electrically driven. Machine-tools with electrical drive are faster and more accurate than hand tools: they were an important element in the development of mass-production processes, as they allowed individual parts to be made in large numbers so as to be interchangeable.
All machine-tools have facilities for holding both the workpiece and the tool, and for accurately controlling the movement of the cutting tool relative to the workpiece. Most machining operations generate large amounts of heat, and use cooling fluids (usually a mixture of water and oils) for cooling and lubrication.
Machine-tools usually work materials mechanically but other machining methods have been developed lately. They include chemical machining, spark erosion to machine very hard materials to any shape by means of a continuous high-voltage spark (discharge) between an electrode and a workpiece. Other machining methods include drilling using ultrasound, and cutting by means of a laser beam. Numerical control of machine-tools and flexible manufacturing systems have made it possible for complete systems of machine-tools to be used flexibly for the manufacture of a range of products.
Vocabulary:
machine-tools — станки
electrically driven — с электроприводом
shape — форма
workpiece — деталь
accurate — точный
development — развитие
to allow — позволять, разрешать
interchangeable — взаимозаменяемый
facility — приспособление
relative —относительный
amount — количество
fluid — жидкость
to lubricate — смазывать
spark erosion — электроискровая обработка
discharge — разряд
by means of — посредством
beam — луч
drilling — сверление
flexible — гибкий
range — ассортимент, диапазон
Text B: «LATHE»
Lathe is still the most important machine-tool. It produces parts of circular cross-section by turning the workpiece on its axis and cutting its surface with a sharp stationary tool. The tool may be moved sideways to produce a cylindrical part and moved towards the workpiece to control the depth of cut. Nowadays all lathes are power-driven by electric motors. That allows continuous rotation of the workpiece at a variety of speeds. The modern lathe is driven by means of a headstock supporting a hollow spindle on accurate bearings and carrying either a chuck or a faceplate, to which the workpiece is clamped. The movement of the tool, both along the lathe bed and at right angle to it, can be accurately controlled, so enabling a part to be machined to close tolerances. Modern lathes are often under numerical control.
Vocabulary:
lathe — токарный станок
circular cross-section — круглое поперечное сечение
surface — поверхность
stationary — неподвижный, стационарный
sideways — в сторону
variety — разнообразие, разновидность
depth — глубина
headstock — передняя бабка
spindle — шпиндель
chuck — зажим, патрон
faceplate — планшайба
lathe bed — станина станка
to enable — давать возможность
tolerance — допуск
General understanding:
1. What are machine-tools used for?
2. How are most machine-tools driven nowadays?
3. What facilities have all machine-tools?
4. How are the cutting tool and the workpiece cooled during machining?
5. What other machining methods have been developed lately?
6. What systems are used now for the manufacture of a range of products without the use of manual labor?
7. What parts can be made with lathes?
8. How can the cutting tool be moved on a lathe?
9. How is the workpiece clamped in a lathe?
10. Can we change the speeds of workpiece rotation in a lathe?
11. What is numerical control of machine tools used for?
Exercise 4.1. Find English equivalents in the text:
1. обрабатываемый материал
2. электропривод
3. более точный
4. отдельные детали
5. процесс массового производства
6. приспособления для держания резца и детали
7. операции по механической обработке детали
8. высоковольтный разряд
9. сверление ультразвуком
10. резание с помощью лазерного луча
11. гибкие производственные системы
12. детали круглого сечения
13. поворачивать деталь вокруг ее оси
14. двигать в сторону, двигать по направлению к детали
15. глубина резания
16. непрерывное вращение детали
17. движение резца вдоль станины
Exercise 4.2. Translate into English:
1. Токарный станок позволяет производить детали круглого сечения.
2. Деталь зажимается в патроне или на планшайбе токарного станка.
3. Резец может двигаться как вдоль станины, так и под прямым углом к ней.
4. Современные токарные станки часто имеют цифровое управление.
Text С: «MILLING MACHINE»
In a milling machine the cutter (фреза) is a circular device with a series of cutting edges on its circumference. The workpiece is held on a table that controls the feed against the cutter. The table has three possible movements: longitudinal, horizontal, and vertical; in some cases it can also rotate. Milling machines are the most versatile of all machine tools. Flat or contoured surfaces may be machined with excellent finish and accuracy. Angles, slots, gear teeth and cuts can be made by using various shapes of cutters.
Drilling and Boring Machines
To drill a hole usually hole-making machine-tools are used. They can drill a hole according to some specification, they can enlarge it, or they can cut threads for a screw or to create an accurate size or a smooth finish of a hole.
Drilling machines (сверлильные станки) are different in size and function, from portable drills to radial drilling machines, multispindle units, automatic production machines, and deep-hole-drilling machines.
Boring (расточка) is a process that enlarges holes previously drilled, usually with a rotating single-point cutter held on a boring bar and fed against a stationary workpiece.
Shapers and Planers
The shaper (поперечно-строгальный станок) is used mainly to produce different flat surfaces. The tool slides against the stationary workpiece and cuts on one stroke, returns to its starting position, and then cuts on the next stroke after a slight lateral displacement. In general, the shaper can make any surface having straight-line elements. It uses only one cutting-tool and is relatively slow, because the return stroke is idle. That is why the shaper is seldom found on a mass production line. It is, however, valuable for tool production and for workshops where flexibility is important and relative slowness is unimportant.
The planer (продольно-строгальный станок) is the largest of the reciprocating machine tools. It differs from the shaper, which moves a tool past a fixed workpiece because the planer moves the workpiece to expose a new section to the tool. Like the shaper, the planer is intended to produce vertical, horizontal, or diagonal cuts. It is also possible to mount several tools at one time in any or all tool holders of a planer to execute multiple simultaneous cuts.
Grinders
Grinders (шлифовальные станки) remove metal by a rotating abrasive wheel. The wheel is composed of many small grains of abrasive, bonded together, with each grain acting as a miniature cutting tool. The process gives very smooth and accurate finishes. Only a small amount of material is removed at each pass of the wheel, so grinding machines require fine wheel regulation. The pressure of the wheel against the workpiece is usually very light, so that grinding can be carried out on fragile materials that cannot be machined by other conventional devices.
Vocabulary:
milling machine — фрезерный станок
series — серия, ряд
cutting edge — режущий край, острие
circumference — окружность
to feed — подавать
longitudinal— продольный
horizontal — горизонтальный
vertical — вертикальный
versatile — универсальный
flat — плоский
contoured — контурный
angle — угол
slot — прорезь, паз
gear teeth — зубья шестерни
drill — дрель, сверло, сверлить
hole — отверстие
to enlarge — увеличивать
thread — резьба
portable — портативный
unit — единица, целое, узел
previously — ранее
to slide — скользить
stroke — ход
lateral — боковой
displacement — смещение
straight — прямой
idle — на холостом ходу
workshop — цех, мастерская
to mount — крепить
holder — держатель
to execute — выполнять
simultaneous — одновременный
multiple — многочисленный
grinder — шлифовальный станок
wheel — круг, колесо
bonded — скрепленный
to remove — удалять
pass — проход
fine — точный
conventional — обычный
device — устройство, прибор
fragile — хрупкий
General understanding:
1. What is the shape of a cutter in a milling machine?
2. What moves in a milling machine, a table or a cutter?
3. What possible movements has the table of a milling machine?
4. What kind of surfaces and shapes may be machined by a milling machine?
5. What can we use a drilling machine for?
6. What kinds of drilling machines exist?
7. What is rotated while boring, a cutter or a work-piece?
8. Describe the work of a shaper (planer).
9. What must be done to execute multiple simultaneous cuts on a planer?
10. What is the working tool in a grinder?
11. Can we obtain a very smooth surface after grinding and why? 12. Can we grind fragile materials and why?
Exercise 4.3. Translate into English:
1. Токарный станок все еще остается самым важным станком.
2. Все современные токарные станки оборудованы электроприводами.
3. Движение инструмента контролируется с высокой точностью.
4. Электропривод позволяет обрабатывать заготовку на различных скоростях.
Text D: «DIES»
Dies are tools used for the shaping solid materials, especially those employed in the pressworking of cold metals.
In presswork, dies are used in pairs. The smaller die, or punch, fits inside the larger die, called the matrix or, simply, the die. The metal to be formed, usually a sheet, is placed over the matrix on the press. The punch is mounted on the press and moves down by hydraulic or mechanical force.
A number of different forms of dies are employed for different operations. The simplest are piercing dies (пробивной штамп), used for punching holes. Bending and folding dies are designed to make single or compound bends. A combination die is designed to perform more than one of the above operations in one stroke of the press. A progressive die permits successive forming operations with the same die.
In coining, metal is forced to flow into two matching dies, each of which bears a engraved design.
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