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5.Растяжение материала выше предела его упругости дает постоянную деформацию или разрушение.

6.Когда деталь работает долгое время под циклическими напряжениями, в ней появляются небольшие растущие трещины из-за усталости металла.

7.Ползучесть — это медленное изменение размера детали под напряжением.

VI. 1) Read the text and divide it into paragraphs; use the phrases below. Render the text:

1. This article is about / the author of the article speaks about … 2. I’d like to call your attention to … 3. One should mention that … 4. It’s interesting to point out that … 5. One should comment upon this question / problem … 6. So / besides / moreover / that is why … 7. On the one hand / on the other hand … 8. In conclusion, I can say that … 9. Considering all the facts …

2) Title the text.

The scientific and technological progress will continue in engineering along two main headlines. Firstly, it is automation, including the creation of “unmanned” industries. Secondly, raising the reliability and extending the service life of machines.

This certainly requires new technology. The machines modules on a large scale are well suited for “unmanned” industries.

Intense work is being carried out on new robots. What we need is not merely manipulators which can take up a workpiece and pass it on, but robots which can identify objects, their position in space, etc.

We also need machines that would trace the entire process of machining. Some have been designed and are manufactured. Modern engineering thinking has created new automated coal digging complexes and machine systems, installations for the continuous casting of steel, machine tools for electrophysical and electrochemical treatment of metals, unique welding equipment, automatic robot transfer lines and machine tool modules for flexible industries.

New technologies and equipment have been designed for most branches of engineering.

In the shortest time possible the engineers are also start producing new generators of machines and equipment which would allow manufactures to increase productivity several times and to find a way for the application of advanced technologies.

Large reserves in extending service life for machines can be found in the process of designing. At present, advanced methods have been evolved for designing machines proceeding from a number of criteria. Automatic design systems allow for an optimizing of the solutions in design and technologies when new machined are still in the blueprint stage.

A promising reserve in increasing the life of parts is strengthening treatment. In recent years new highly efficient methods have been found.

First and foremost of them is the vacuum plasma methods for coating components will hard alloy compounds, such as nitrides and carbides of titanium, tungsten and boron. Methods have been designed for reinforcing machine parts most vulnerable to wear and tear, such as in grain harvesters, to make them last several times longer.

Thus, it is not merely quantity engineers and scientists are after, rather it is a matter of major characteristics. In other words, this is a matter of quality, and not of the mere number of new machines, apparatuses and materials.

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Unit 3

Read the text:

Mechanical Properties of Materials

Density (specific weight) is the amount of mass in a unit volume. It is measured in kilograms per cubic meter. The density of water is 1000 kg/m3 but most materials have a higher density and sink in water. Aluminium alloys, with typical densities around 2800 kg/m3 are considerably less dense than steels, which have typical densities around 7800 kg/m3. Density is important in any application where the material must not be heavy.

Stiffness (rigidity) is a measure of the resistance to deformation such as stretching or bending. The Young modulus is a measure of the resistance to simple stretching or compression. It is the ratio of the applied force per unit area (stress) to the fractional elastic deformation (strain). Stiffness is important when a rigid structure is to be made.

Strength is the force per unit area (stress) that a material can support without failing. The units are the same as those of stiffness, MN/m2, but in this case the deformation is irreversible. The yield strength is the stress at which a material first deforms plastically. For a metal the yield strength may be less than the fracture strength, which is the stress at which it breaks. Many materials have a higher strength in compression than in tension.

Ductility is the ability of a material to deform without breaking. One of the great advantages of metals is their ability to be formed into the shape that is needed, such as car body parts. Materials that are not ductile are brittle. Ductile materials can absorb energy by deformation but brittle materials cannot.

Toughness is the resistance of a material to breaking when there is a crack in it. For a material of given toughness, the stress at which it will fail is inversely proportional to the square root of the size of the largest defect present. Toughness is different from strength: the toughest steels, for example, are different from the ones with highest tensile strength. Brittle materials have low toughness: glass can be broken along a chosen line by first scratching it with a diamond. Composites can be designed to have considerably greater toughness than their constituent materials. The example of a very tough composite is fiberglass that is very flexible and strong.

Creep resistance is the resistance to a gradual permanent change of shape, and it becomes especially important at higher temperatures. A successful research has been made in materials for machine part that operate at high temperatures and under high tensile forces without gradually extending, for example the parts of plane engines.

Assignments:

I.General understanding. Answer the questions:

1.What is the density of a material?

2.What are the units of density? Where is low density needed?

3.A measure of what properties is stiffness? When is stiffness important?

4.What is Young Modulus?

5.What is yield strength? Why is fracture strength always greater than yield strength?

6.What is ductility? Give the examples of ductile materials. Give the examples of brittle materials.

7.What is toughness?

II. Find the following words and word combinations in the text:

Количество массы в единице объема; килограмм на кубический метр; мера сопротивления деформации; отношение приложенной силы на единицу площади к частичной упругой деформации; жесткая конструкция; прочность на сжатие; способность материала деформироваться, не разрушаясь; поглощать энергию путем деформации; обратно

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пропорционально квадрату размера дефекта; постепенное изменение формы; повышенные температуры; высокие растягивающие усилия.

III. Find the words in the text that mean the same as the following phrases:

1.quantity of something (para 1);

2.strength or energy (para 2);

3.stiff and unmoving (para 2);

4.to give assistance to (para 3);

5.pressure or tension (para 3);

6.benefit or profit (para 4);

7.the external form (para 4);

8.a shortcoming, imperfection (para 5);

9.capable of bending easily (para 5);

10.remain unchanged indefinitely (para 6).

IV. Ask alternative questions to the following sentences; then ask disjunctive questions to them:

1.Aluminium alloys, with typical densities around 2800 kg/m3 are considerably less dense than steels, which have typical densities around 7800 kg/m3.

2.The density of water is 1000 kg/m3 but most materials have a higher density and sink in water.

3.The units of strength are the same as those of stiffness, MN/m2, but in this case the deformation is irreversible.

V. Translate into English:

1.Плотность измеряется в килограммах на кубический метр.

2.Большинство материалов имеют более высокую плотность, чем вода и тонут в

воде.

3.Плотность материала очень важна, особенно в авиации.

4.Модуль Юнга — отношение приложенной силы к упругой деформации данного материала.

5.Чем металл жестче, тем менее он деформируется под нагрузкой.

6.Когда металл растягивают, он сначала течет, то есть пластически деформируется.

7.Свинец, медь, алюминий, и золото — самые ковкие металлы.

8.Сопротивление ползучести является очень важным свойством материалов, которые используются в авиационных моторах.

VI. 1) Read and complete the text with the words from the box. 2) Ask all types of questions to the text.

dismantled; requirements; industrialized; products; replaced; design; workshops

Towards Flexible Production Facilities

Present day industry, in particular engineering, is defined by the fact that its 1)… — ma- chine-tools, devices, instruments, etc. — are normally produced for a very short period of time and 2) … by other more advanced products. The range of products is growing and the size of batches is decreasing. The new production environment has brought about new 3) … . Thus, for example, earlier functionally “rigid” automatic production lines require considerable changes to be introduced or the line to be fully 4) … when the factory switches to a new product. Unlike the above lines, flexible production lines can be switched over to a new prod-

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uct virtually instantaneously. When operated on 24-hour basis, these lines need only a minimal team of operations to attend the production.

The highest level of flexible production facility, an automatic factory, incorporates several flexible production 5) … . Such a factory has both automated equipment and automated services, including computer-aided 6) … of products and processes, and software development for its control system. Such automated factories are being designed and are expected to become fully operational in the near future. All the 7) … countries are currently making use of flexible modules and workshops.

Unit 4

I. Work in small groups. Why did engineers create machine tools? Can any machine tool replace a man at work? Compare the answers with other students and give reasons to support your ideas.

Mini Lathe

Read the text:

Machine Tools (Part I)

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 controls of machine-tools and flexible manufac-

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turing systems have made it possible for complete systems of machine-tools to be used flexibly for the manufacture of a range of products.

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.

Assignments:

II. General understanding. Answer the questions:

1.What are machine tools used for?

2.What facilities do all machine tools have?

3.How are the cutting tool and the workpiece cooled during machining?

4.What parts can be made with lathes?

5.How can the cutting tool be moved on a lathe?

6.How is the workpiece clamped in a lathe?

7.What is numerical control used for?

III. Find English equivalents in the text:

Обрабатываемый материал; электропривод; более точный; отдельные детали; процесс массового производства; приспособления для держания резца и детали; операции по механической обработке детали; высоковольтный разряд; сверление ультразвуком; резание с помощью лазерного луча; гибкие производственные системы; детали круглого сечения; поворачивать деталь вокруг ее оси; двигать в сторону; двигать по направлению детали; глубина резания; непрерывное вращение детали; движение резца вдоль станины.

IV. Find synonyms in the text to the following words:

Quick; mould; component; instrument; diversity; fabrication; way; activity; engine; exchangeable.

V. Say whether these sentences are true (T) or false (F):

1.Facilities in all machine tools are used to hold workpiece as well as the tool.

2.Nowadays almost every machine tool is electrically driven.

3.Cooling happens itself, without special fluids.

4.We can’t change the speeds of workpiece rotation in a lathe.

VI. 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.

5.Большинство станков сейчас с электроприводом, они работают быстрее и точнее, чем станки прошлых поколений.

6.Токарный станок все еще остается самым важным станком.

7.Все современные токарные станки оборудованы электроприводами.

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8.Движение инструмента контролируется с высокой точностью.

9.Электропривод позволяет обрабатывать заготовку на различных скоростях.

VII. 1) Translate this text in a written form using a dictionary.

2) Ask five special questions to it.

The various complicated machine-tools now used by engineers are designed to do the same jobs as the hammer, the chisel and the file, but very much more quickly and efficiently, and with much wider range of application. The vastly increased production of modern times would never have been possible without these machines to take the place of hand work, nor could the hand-worker ever produce the precision now needed.

The machine tools which have replaced the chisel and file and which shape the metal by removing parts of it are shapers, planers, milling machines, drilling and boring machines, grinders and lathes and those which have replaced the hammer and which press the metal into the required shape are steam hammers, forging and pressing machines and sheet metal work tools.

VIII. Render the text in English:

Процесс нанесения нарезов называется дорнованием. Станок представляет собой горизонтальный пресс с копиром, который задает шаг нарезов. Если проще, станок, плавно вращая, протягивает через канал ствола твердосплавный дорн очень высокой твердости (70–80 единиц по шкале твердости Роквелла; сталь для ствола, например, имеет твердость 32–34 единицы) с выступающими нарезами. Это однократная операция, которая буквально за десять секунд образует нарезы методом давления. Перед протяжкой дорна на внутренний канал ствола для уменьшения трения наносится специальная смазывающая жидкость, состав которой является профессиональной тайной каждого ствольного производителя и держится в секрете.

Под каждый калибр и шаг (плюс-минус дюйм) требуется отдельный дорн. Например, под 30-й калибр есть дорн на шаг 12 дюймов. Это значит, что на станке можно делать нарезы с шагом от 11 до 13 дюймов.

Дорн — самая дорогая позиция из всего инструмента оружейника и в зависимости от калибра стоит от $1000 до 3000. Дорн — долгожитель. Если за ним правильно ухаживать (а после каждого прохода дорн заново полируют, чтобы убрать возможные микрозадиры), то его может хватить на несколько тысяч стволов.

Плюс такой технологии образования нарезов состоит в том, что она создает поверхностное упрочение канала ствола, что в свою очередь благотворно сказывается на ресурсе

истойкости к температурным воздействиям. Минус — неизбежность внутренних напряжений, которые приходится снимать. Если не умеешь снимать напряжения, то образование нарезов методом дорнования — путь в никуда, говорит Лобаев (основатель компании «Царь-пушка»). Это ноу-хау. На словах все очень просто — нагревание до определенной температуры, а затем охлаждение. Температурные режимы подбираются индивидуально под разные марки сталей. Если сильно отпустить — потеряем живучесть, ствол станет более пластичным. Если же держать большую твердость — можно не отпустить напряжение

иствол будет изгибаться после нескольких выстрелов под воздействием температур, напоминая стволы, сделанные по технологии ротационной ковки.

Нарезка в «Царь-пушке» — самый быстрый процесс — всего десять секунд. Сверление, например, занимает час — час двадцать, а развертывание — минут тридцать.

«Популярная механика»

Use the words and phrases given below:

Шаг — pitch; нарез — groove; дорнование / дорн — burnishing / burnisher; канал ствола — bore of the barrel; твердосплавный — hardmetal, hard-alloy; шкала твердости Роквелла — Rockwell’s scale; протяжка — broach; трение — friction, dragging; калибр —

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calibre; дюйм — inch; долговечный — durable; полировать — glaze; убрать задиры — remove tears; плюс / минус — advantage / disadvantage; температурные воздействия — temperature effects; внутреннее напряжение — internal stress; нагревание / охлаждение — heating / cooling; ротационная ковка — rotary forging.

Unit 5

Boring Machine

Read the text:

Machine Tools (Part II)

Milling Machine

In a milling machine the cutter 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 are different in size and function, from portable drills to radial drilling machines, multispindle units, automatic production machines, and deep-hole-drilling machines.

Boring is a process that enlarges holes previously drilled, usually with a rotating singlepoint cutter held on a boring bar and fed against a stationary workpiece.

Shapers and Planers

The shaper 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,

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however, valuable for tool production and for workshop where flexibility is important and relative slowness is unimportant.

The planer 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 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.

Assignments:

I.General understanding. Answer the questions:

1.What is the shape of cutter in a milling machine?

2.What possible movements does the table in a milling machine have?

3.What kind of surfaces and shapes may be machined by a milling machine?

4.What can we use a drilling machine for?

5.What is rotated while boring, a cutter or a workpiece?

6.Describe the work of a shaper and planer.

7.What is the working tool in a grinder?

II. Find these words and word combinations in the text:

Плоские и контурные поверхности; удалять металл; вертикальный; шлифовальный станок; различаться по размерам и функциям; хрупкие материалы; круглое устройство; вращаться; инструмент скользит; в цехах важна гибкость; обычный прибор; создавать четкий размер; на холостом ходу; фрезерный станок; универсальный; резьба; редко можно найти в массовом производстве; горизонтальный; в отличие от.

III. Match words to get phrases according to the text:

IV. Say whether these sentences are true (T) or false (F):

1.Rotational movement always takes place in a milling machine.

2.The wheel in grinders is composed of many coarse grains.

3.The planer produces vertical, horizontal, or diagonal cuts.

4.Boring is a process that makes the holes smaller previously drilled.

5.Shaper is quite slow machine tool because it uses one cutting tool.

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V. Guess the name of a machine tool:

1.Hole-making machine-tool is … .

2.It uses only one cutting tool.

3.It has a rotating abrasive wheel.

4.It is the largest of the reciprocating machine tools.

5.It has four possible movements: longitudinal, horizontal, vertical and rotational.

6.Fragile materials are used on this machine tool.

7.There are many kinds of it.

VI. 1) Fill in the table according to the text. You may use additional information from this site: http://www.dunhamtool.com/machine_tool_industry.htmll

2) Take one of the machine tools and tell everything you know about it.

Lathe

Milling machine

Drilling machine

Boring machine

Grinder

Shaper

Planer

VII. Render the text in English:

Болванки

Сталь поступает в виде шестиметровых прутков, которые нарезают на нужные куски. Изначально заготовки довольно неровные, поэтому их заказывают с припуском под проточку и на токарном станке обтачивают до идеального цилиндра нужного диаметра. Максимальная длина стволов, которую может сверлить «Царь-пушка» на своем оборудовании, — 95 см. Все оборудование для производства американское, что объясняется просто: в США несколько сотен (!) производителей высокоточных стволов и винтовок, и эта отрасль развита как нигде в мире. К тому же искусство изготовления таких винтовок Владислав (основатель компании «Царь-пушка») постигал именно в Америке.

После того как заготовки обточены до нужного диаметра, они вставляются в двухшпиндельный сверлильный станок, на котором можно одновременно обрабатывать пару стволов. Используется специальный инструмент — сверла глубокого сверления. В «Царь-пушке» есть практически вся гамма калибров: . 22, . 25, . 270, . 234 (6 мм), 7 мм, 6,5 мм, . 30 (7,62 мм), . 338 (8,6 мм) и . 408 (10,3 мм). 408-й калибр — гордость Лобаева.

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«В Европе его делаем мы единственные. Это не на слонов ходить, а для стрельбы на 2– 3 км», — добавляет Владислав.

Основная проблема в данной операции — увод инструмента от оси сверления. Борются с ней выбором правильного режима обработки (скорость подачи и оборотов) и — самое главное — правильной заточкой сверла. Это вообще ключевая операция — если заточник заболеет, производство может остановиться.

Одно сверло без перезаточки, в зависимости от марки стали, выдерживает от 10 до 50 стволов. Комплект из пары сверл стоит $1500–2000, и при правильном уходе они живут практически вечно. С советских времен ходят байки, что самые лучшие стволы — первые из партии, высверленной одним сверлом. Это бред, поясняет Владислав Лобаев, так как сверление — хотя и важная, но предварительная, а не финишная обработка канала ствола.

После сверления ствол маркируется. Например, 338 — калибр, далее 323 — диаметр сверла, 330 — диаметр развертки, 3415 — дорн, 12 — шаг и 75 — технологический номер партии, по которому компания может отследить судьбу конкретного ствола. Допустим, если какой-то ствол рекордно хорошо стреляет и минимально реагирует на ветер, по маркировке можно восстановить технологию и сделать «близнеца». Из одной партии (1,5–2 т) стали получают 240–320 стволов.

«Популярная механика»

Use the words and phrases given below:

Болванка — blank, pig; прут — rod, stick; неровный –uneven; припуск — stock; проточка — cavity, groove; оборудование — equipment; высокоточный — high-precision; обтачивать — lathe, turn; ось сверления — drilling axis; перезаточка — regrinding; предварительный — preliminary.

Unit 6

Bending Die

Read the text:

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 large 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, 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 opera-

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