UNIT 3. TECHNICAL DRAWING

Цель: освоить во всех видах речевой деятельности новые лексические единицы по теме «Technical drawing»; развивать навыки работы с информацией; научиться слушать, читать тексты, вести разговор по теме.

Задачи: развитие умений изучающего чтения; расширение объёма продуктивного словарного запаса за счёт освоения новых лексических единиц по теме; развитие умений передавать содержание прочитанного.

1. Read the text about technical drawing and translate it into Russian:

Technical drawing,also known as drafting,is the act and discipline of composing plans. The main purpose of technical drawing is to describe or explain all the characteristics of a product, giving all the necessary information that will help a manufacturer to produce that component. The visual image should be accurate in terms of dimensions and proportions, and should provide an overall impression of what an object is or does. It is a precise task requiring a high level of skilland suitable engineering tools.

A drafteris the person who makes a drawing and who requires a wide knowledge of geometry, trigonometry and spatial comprehension, and in all cases must be precise and accurate and give great attention to detail. People who communicate with technical drawings use a visual language and technical standards that define practical symbols, perspectives and units of measurement. What are the tools and instruments used by a drafter in manual drafting? A T-square, a protractor, a compass, rulers,and triangles.Paper is also important and can be divided into layout paper, which is thin and fragile, and cartridge paper, which is heavier and more suitable for final drawings. Pencils used in drawing are graded from H to F depending on the hardness.The final drawing is made using a technical pen, graded according to the point,which must maintain the same line width.They are used with a range of stencils to add symbols, letters and patterns to the drawing. Rubbers remove pencils or pen writing when mistakes are found. Correction fluid is used to mask text errors.

2. Read the text again and choose the correct answer:

1. Technical drawing is needed to ...

A. make a scale of the product.

B. practise pens, rulers and stencils.

C. let the manufacturer understand the requirements.

2. The drafter needs ...

A. some paper and a pencil.

B. a wide range of technical instruments.

C. the final product.

3. Paper is chosen considering ...

A. what sort of drawing the drafter is going to make.

B. the pencils he/she is going to use.

C. the drafter's preference.

4. Pencils are graded according to ...

A. hardness.

B. hardness and colour.

C. hardness and point.

5. A technical pen ...

A. makes regular lines.

B. maintains the same line width.

C. draws lines of the same length.

6. When mistakes are found ...

A. we can't correct them.

B. they're removed with correction fluid.

C. stencil can cover them.

CAD/CAM SYSTEMS

3. Read the text about CAD/CAM systems and translate it into Russian:

Drawing boards and manual drawing are not always precise and rapid: traditional design is usually slow, especially in its revision and modification. For this reason manufacturing firms have replaced manual drawing with computer-aided design (CAD) to carry out functions related to design and production. This computer technology assists the designer in the creation, modification and analysis of a physical object.

Nowadays computer software can easily provide a three-dimensional drawing, which allows engineering designers to see how mechanical components may fit together without making models thus saving a lot of time. CAD is much faster and more accurate than manual drawing; designs can be quickly modified, reproduced and transmitted electronically. Computer simulated analysis of the model helps experts find problems and defects without building prototypes, in this way saving a lot of money and time. When the design is ready, the CAD system can generate the detailed drawings needed to start product manufacturing.

When CAD systems are linked to manufacturing equipment controlled by computers, they form an integrated CAD/CAM system. Computer-aided manufacturing (CAM) offers significant advantages over traditional approaches by controlling manufacturing equipment with computers instead of human labour. CAM converts the design of a component into computer language and it gives instructions to the computer regarding machine operations. Thanks to CAD/CAM systems it is possible to eliminate operator errors and reduce manufacturing costs.

4. Read the text again and match each sentence with its ending:

1. CAD helps designers a. seen from any angle and are easily manipulated.

2. By using a CAD technology b. to draw, modify and correct designs.

3. Unlike manual drawing, CAD c. the design into computer language.

4. CAD allows us to save d. defects can be easily found.

5. CAD designs can be e. provides three-dimensional drawings.

6. CAM is the use of computer software f. time and money.

7. The CAM system turns g. minimise errors and manufacturing costs.

8. CAD/CAM systems h. to control machine tools in the manufacturing process.

MY GLOSSARY [UNIT 3]:

to carry out ________

drafter ____________

drafting ___________

to fit _____________

hardness __________

point _____________

prototype __________

protractor __________

to replace _______________

ruler ___________________

skill ____________________

technical drawing _________

to save _________________

triangle _________________

T-square ________________

width___________________

UNIT 4. MACHINE TOOLS

Цель: научиться слушать, читать тексты, вести разговор по теме «Machine tools».

Задачи: развитие умений изучающего чтения; расширение объёма продуктивного словарного запаса за счёт освоения новых лексических единиц по теме; развитие умений диалогической речи – диалог расспрос на основе прочитанного.

1. Read the text about machine tools and translate it into Russian:

A machine tooluses a power source to modify the shape of metal components of machines. Itis a sort of machine used as a tool in the making of other machines. Machine tools were powered in the Middle Ages by humans and animals, and later by the energy captured by waterwheels. After the Industrial Revolution, most machine tools were powered by steam engineand nowadays by electricity.

Machine tools can be operated manually, or under automatic control. In the 1960s, computers gave more flexibility to the process. Such machines became known as computerized numerical control (CNC) machines. They could precisely repeat sequences, and could produce much more complex pieces than even the most skilled tool operators. Let's examine the main featuresof some of the most commonly used machine tools.

Turning machine

The engine latheis the most important of all the machine tools. It is used to produce external or internal cylindrical surfaces. The piece is held by the machine and is rotated while a cutting tool removes excess metal from the external diameter. Internal turning consists of enlarging and finishing a hole.

Shaper

This is a metal-cutting machine used to produce or modify flat surfaces. The cutting tool moves cutting on the forward stroke, with the piece feeding automatically towards the tool during each return stroke. Shapers can be horizontal or vertical.

Drilling machine

It is used to produce circular holes in metal with a twist drill. It also uses a variety of other cutting tools to perform the basic hole-machining operations.

Milling machine

This cuts flat metal surfaces. The piece is fed against a rotating cutting tool. Cutters of many shapes and sizes are available for a wide variety of milling operations. Milling machines may be manually operated, mechanically automated, or digitally automated via computer numerical control (CNC).

Grinding machine

This removes excessive material from parts that are brought into contact with a rotating abrasive wheel. Grinding is the most accurate of all the basic machining processes, but also the most time consuming.

Press

This is a machine tool that changes the shape of a workpiece. Historically, metal was shaped by hand using a hammer. Machine presses can be dangerous. Bi-manual controls (controls which require both hands to be on the buttons to operate) are a very good way to prevent accidents.

Band saw

It is a power tool which uses a blade consisting of a continuous band of metal with teeth along one edge. The band usually rides on two wheels rotating in the same plane. Band saws are used for woodworking, metalworking, or for cutting a variety of other materials, and are particularly useful for cutting irregular or curved shapes. A constant flow of liquid is poured over the blade to keep it cool and preventing it from overheating.

2. Complete the table:

3. Read the texts again and decide if the following sentences are true (T) or false (F):

1. Turning machines remove excess metal from the external diameter and enlarge and finish a hole.

2. Shapers can only be vertical.

3. Drilling machines use a twist drill to make circular holes.

4. Milling machines can only be manually operated.

5. Grinding machines remove excessive material from parts.

6. Band saws use a band of metal with teeth to cut various parts.

7. Presses are not dangerous if operated by both hands.

MY GLOSSARY [UNIT 4]:

band saw ______________

blade__________________

cool___________________

drilling machine__________

feature_________________

grinding machine_________

hole___________________

lathe__________________

machine tool____________

overheating______________

press___________________

programmer______________

shaper__________________

skilled__________________

steam engine_____________

stroke___________________

turning machine___________

waterwheel_______________

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