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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 6.3. 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.
Wiredrawing Dies
In the manufacture of wire, a drawplate (волочильная доска) is usually employed. This tool is a metal plate containing a number of holes, successively less in diameter and known as wire dies. A piece of metal is pulled through the largest die to make a coarse wire. This wire is then drawn through the smaller hole, and then the next, until the wire is reduced to the desired measurement. Wiredrawing dies are made from extremely hard materials, such as tungsten carbide or diamonds.
Thread-Cutting Dies
For cutting threads on bolts or on the outside of pipes, a thread-cutting die (резьбонарезная плашка) is used. It is usually made of hardened steel in the form of a round plate with a hole in the center. The hole has a thread. To cut an outside thread, the die is lubricated with oil and simply screwed onto an unthreaded bolt or piece of pipe, the same way a nut is screwed onto a bolt. The corresponding tool for cutting an inside thread, such as that inside a nut, is called a tap (метчик).
Vocabulary:
chip — стружка
sharp — острый
friction — трение
content — содержание
range — диапазон
inexpensive — недорогой
to permit — позволять, разрешать
common — обычный
tungsten — вольфрам
ingredient — ингредиент
diamond — алмаз
tips — наконечники
ceramic — керамический
truing — правка, наводка, заточка
die — матрица, штамп
matrix — матрица
to employ — применять
to pierce — протыкать, прокалывать
to punch — пробивать отверстие
matching — сочетающийся, парный
coarse — грубый
wire — проволока
to draw — тащить, волочить
thread — резьба
hardened — закаленный
to lubricate — смазывать
to screw — привинчивать
nut — гайка
outside — наружный, внешний
inside — внутри, внутренний
Exercise 6.4. Find English equivalents in the text:
1. удалять металлическую стружку
2. острый режущий край
3. содержание углерода
4. режущая способность
5. сталь для скоростного резания
6. правка шлифовальных кругов
7. гидравлическое или механическое давление
8. различные формы штампов
Exercise 6.5. Translate the following sentences into Russian:
1. Все резцы и фрезы должны иметь острую режущую кромку.
2. Во время резания режущий инструмент и деталь имеют высокую температуру и должны охлаждаться.
3. Углеродистые стали часто используются для изготовления резцов потому, что они недорогие.
4. Быстрорежущие стали содержат вольфрам, хром и ванадий.
5. Алмазы используются для резания абразивных материалов и чистовой обработки поверхности твердых материалов.
6. Для различных операций используют различные штампы.
7. Волочильные доски для проволоки делаются из очень твердых материалов.
8. Резьбонарезные плашки и метчики используются для нарезки резьбы снаружи и внутри.
UNIT 7
AUTOMATION AND ROBOTICS
Text A: AUTOMATION
Text B: TYPES OF AUTOMATION
Text C: ROBOTS IN MANUFACTURING
Text A: AUTOMATION
Automation is the system of manufacture performing certain tasks, previously done by people, by machines only. The sequences of operations are controlled automatically. The most familiar example of a highly automated system is an assembly plant for automobiles or other complex products.
The term automation is also used to describe non-manufacturing systems in which automatic devices can operate independently of human control. Such devices as automatic pilots, automatic telephone equipment and automated control systems are used to perform various operations much faster and better than could be done by people.
Automated manufacturing had several steps in its development. Mechanization was the first step necessary in the development of automation. The simplification of work made it possible to design and build machines that resembled the motions of the worker. These specialized machines were motorized and they had better production efficiency.
Industrial robots, originally designed only to perform simple tasks in environments dangerous to human workers, are now widely used to transfer, manipulate, and position both light and heavy workpieces performing all the functions of a transfer machine.
In the 1920s the automobile industry for the first time used an integrated system of production. This method of production was adopted by most car manufacturers and became known as Detroit automation.
The feedback principle is used in all automatic-control mechanisms when machines have ability to correct themselves. The feedback principle has been used for centuries. An outstanding early example is the flyball governor, invented in 1788 by James Watt to control the speed of the steam engine. The common household thermostat is another example of a feedback device.
Using feedback devices, machines can start, stop, speed up, slow down, count, inspect, test, compare, and measure. These operations are commonly applied to a wide variety of production operations.
Computers have greatly facilitated the use of feedback in manufacturing processes. Computers gave rise to the development of numerically controlled machines. The motions of these machines are controlled by punched paper or magnetic tapes. In numerically controlled machining centres machine tools can perform several different machining operations.
More recently, the introduction of microprocessors and computers have made possible the development of computer-aided design and computer-aided manufacture (CAD and CAM) technologies. When using these systems a designer draws a part and indicates its dimensions with the help of a mouse, light pen, or other input device. After the drawing has been completed the computer automatically gives the instructions that direct a machining centre to machine the part.
Another development using automation are the flexible manufacturing systems (FMS). A computer in FMS can be used to monitor and control the operation of the whole factory.
Automation has also had an influence on the areas of the economy other than manufacturing. Small computers are used in systems called word processors, which are rapidly becoming a standard part of the modern office. They are used to edit texts, to type letters and so on.
AUTOMATION IN INDUSTRY
Many industries are highly automated or use automation technology in some part of their operation. In communications and especially in the telephone industry dialing and transmission are all done automatically. Railways are also controlled by automatic signaling devices, which have sensors that detect carriages passing a particular point. In this way the movement and location of trains can be monitored.
Not all industries require the same degree of automation. Sales, agriculture, and some service industries are difficult to automate, though agriculture industry may become more mechanized, especially in the processing and packaging of foods.
The automation technology in manufacturing and assembly is widely used in car and other consumer product industries.
Nevertheless, each industry has its own concept of automation that answers its particular production needs.
Vocabulary:
automation — автоматизация
previously — ранее
sequence — последовательность
assembly plant — сборочный завод
non - manufacturing — непроизводственный
device — устройство, прибор
resemble — походить
efficiency — эффективность
flyball governor — центробежный регулятор
steam engine — паровоз
household thermostat — бытовой термостат
facilitate — способствовать
punched — перфорированный
aid — помощь
dimension — измерение, размеры
General understanding:
1. How is the term automation defined in the text?
2. What is the most «familiar example» of automation given in the text?
3. What was the first step in the development of automaton?
4. What were the first robots originally designed for?
5. What was the first industry to adopt the new integrated system of production?
6. What is feedback principle?
7. What do the abbreviations CAM and CAD stand for?
8. What is FMS?
9. What industries use automation technologies?
Exercise 7.1. Find the following words and word combinations in the text:
1. автоматические устройства
2. автоматизированное производство
3. выполнять простые задачи
4. как легкие, так и тяжелые детали
5. интегрированная система производства
6. принцип обратной связи
7. механизм может разгоняться и тормозить
8. компьютер автоматически посылает команды
9. высокоавтоматизированная система
10. непроизводственная система
Text В. TYPES OF AUTOMATION
Дата: 2019-02-25, просмотров: 489.