Добавил:
ivanov666
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:English for engineers in construction mechanization and automation (Коммуникативный метод обучения профессиональному английскому языку). Учебное пособ
.pdf
12
1. Answer the following questions:
1. How were hand tools used before the Industrial Revolution?
2. Who designed and built a screw-cutting engine lathe?
3. Who invented the shaper?
4. What was the International Exhibition of 1862 famous for?
5. What countries were British tools exported to?
6. When was the first fully universal milling machine built?
7. Did the production of artificial abrasives open up a new field of
machine tools?
2. Match the words and their Russian equivalents:
1) hread ось, вал, шпиндель
2) flute фрезерный станок по дереву
3) pitch привод, шестерня, зубчатая передача
4) shaper зажимное приспособление
5) reciprocation выравнивать, строгать
6) to plane винтовой
7) jig выемка, желобок
8) helical возвратно-поступательное движение
9) spindle шаг, расстояние, уклон
10) gear резьба, нарезка
3. Which sentences are true (T) and false (F).
1. Machine tools became the important innovations for the mankind.
2. Henry Maudslay designed and built a screw-cutting engine lathe in
the XVIII century.
3. The shaper was invented by Joseph Whitworth in the USA.
4. The turret lathe, developed in Britain in the middle of the 19th cen-
tury, was fully automatic in some operations.
5. The shaper was invented by Henry Maudslay in London.
6. British tools were exported to Europe and to the United States in
spite of the ban.
4. Insert the prepositions:
1. Because … the precise dimensional requirements … the parts and
the heavy cutting forces exerted … the cutting tool, machine tools combine
weight and rigidity … delicate accuracy.
13
2. Some … them were adaptations … earlier woodworking machines.
3. The production of artificial abrasives … the late 19th century
opened … a new field … machine tools.
4. … the end of the 19th century a complete revolution had taken place
… the working and shaping … metals that created the basis … mass pro-
duction and an industrialized society.
5. Britain tried to keep its lead … machine-tool development … pro-
hibiting exports, but the attempt was foredoomed … industrial develop-
ment.
Additional text. Read and translate it from English into Russian
Gear-cutting machines
Three basic cutting methods are used for machining gears: 1) form
cutting, 2) template cutting, and 3) generating. The form-cutting method
uses a cutting tool that has the same form as the space between two adjacent teeth on a gear. This method is used for cutting gear teeth on a milling
machine. The template-cutting method uses a template to guide a singlepoint cutter on large bevel-gear cutting machines.
Most cut gears produced in large lots are made on machines that utilize the gear-generating method. This method is based on the principle that
two involute gears, or a gear and rack, with the same diametral pitch will
mesh together properly. Therefore, a cutting tool with the shape of a gear
or rack may be used to cut gear teeth in a gear or rack blank. This principle
is applied in the design of a number of widely used gear-cutting machines
of the generating type. Gear-generating machines that cut with reciprocating strokes are called gear shapers.
Gear-hobbing machines use a rotating, multiple-tooth cutting tool
called a hob for generating teeth on spur gears, worm gears, helical gears,
splines, and sprockets. More gears are cut by hobbing than by other
methods because the hobbing cutter cuts continuously and produces accurate gears at high production rates. In gear-making machines gears can be
produced by cutting, grinding, or a combination of cutting and grinding
operations.
14
Unit 2. BASIC MACHINE TOOLS
Vocabulary
1) an engine lathe токарно-винторезный станок
2) turning обточка
3) screw cutting нарезание винтов
4) a bed станина
5) a headstock передняя бабка
6) a tailstock задняя бабка
7) a carriage суппорт
8) iron чугун
9) a casting отливка
10) a saddle салазки
11) a lever рычаг
12) an apron фартук
13) guide ways направляющие
14) to retain фиксировать, держать
15) reaming развертывание, расширение отверстий
16) a countersink зенковка, конический зенкер
17) a feed подача, подводка, питание
18) angular угловой
19) to oscillate вибрировать, колебаться, качаться
20) a mount крепление, опора, держатель, основа
21) a workpiece обрабатываемое изделие
22) a stroke удар, ход движения
23) a collet цанга; зажимная втулка, цанговый патрон
24) a spanner гаечный ключ
25) a countershaft контрпривод; промежуточный вал
Text 1.
PRECISION BENCH AND ENGINE LATHES
Hundreds of varieties of metal machine tools are used in modern
industry. They retain the basic characteristics of their XIX and early
XX century forefathers.
15
The engine lathe, as the horizontal metal-turning machine is the most
important of all the machine tools. It is usually considered the father of all
other machine tools because many of its fundamental mechanical elements
are integrated into the design of other machine tools.
The engine lathe is a basic machine tool that can be used for a variety
of turning, facing and drilling operations. It uses a single-point cutting tool
for turning and boring. Turning operations involve cutting excess metal in
the form of chips from the external diameter of a workpiece and include
turning straight or tapered cylindrical shapes, grooves, shoulders and
screw threads and facing flat surfaces on the ends of cylindrical parts. Internal cylindrical operations include most of the common hole-machining
operations such as drilling, boring, reaming, counterboring, countersinking
and threading with a single-point tool or tap.
Boring involves enlarging and finishing a hole that has been cored or
drilled. Bored holes are more accurate in roundness, concentricity and parallelism than drilled holes. A hole is bored with a single-point cutting tool
that feeds along the inside of the workpiece. Boring mills have circular
horizontal tables that rotate about a vertical axis and they are designed for
boring and turning operations on parts that are too large to be mounted on
a lathe.
The precision lathes with back-gear comprise: bed with securing bolts,
head-stock with back-gear, split collet device and one collet, carrier plate,
hardened center and protecting nut for the spindle nose thread, tail-stock
with hardened plain and hollow centers, compound slide rest for parallel
and taper turning, hand tool rest with two tees (or with one Tee) overhead
countershaft with ring lubrication, loose pulley with lubricator and replaceable bush, set of spanners and instruction sheet.
The back-gear is at the front end of the head-stock, and is protected by
a detachable cast guard. The gears are machined from steel and hardened
in the bearing surfaces. The pinion which meshes with the belt pulley is
machined from phosphor-bronze.
The construction of this head-stock with back-gear gives most satisfactory results, an important feature being the locking of the gear spindle,
16
and the accurate machining of the gear system, which produces a very even
and quiet action. The axial thrust is taken up on a special thrust hearing.
The principal units of the lathe are the bed, the headstock, the tailstock
and the carriage with the apron. The bed is the base of any machine-tool
and it is made of grey iron casting on which the saddle and the tailstock
slide along special guideways. The headstock is also located and bolted on
the bed. The headstock contains the spindle and the speed gearbox. The
spindle is the part of the machine to which power is applied to rotate the
work. The changing of the spindle speed is affected by levers. The tailstock consists of a casting fitted to the bed. The function of the tailstock is
to support one end of the work turned between centers and to mount the
tools. The carriage of the lathe, which carries the tool, is made up of two
principal parts: the saddle and the apron. The saddle travels along the
guideways of the bed. The apron represents the front wall of the carriage.
On the front of the apron the handles and levers are mounted by which the
actions of the tool are controlled.
1. Describe the components of the engine lathe:
Engine lathe
1. gearbox and headstock; 2. tailstock; 3. frame; 4. spindle; 5. feed gearbox;
6. electric motor; 7. control panel; 8. cross slide; 9. carriage; 10. tool block;
11. ways; 12. lead screw; 13. feed rod; 14. operating lever shaft; 15. operating and
reverse handle; 16. apron; 17. hand feed wheel.
17
2. Answer the questions:
1. Why is the engine lathe the most important of all the machine tools?
2. What is the engine lathe used for?
3. What facilities has engine lathe?
4. What are the principal units of the precision lathe?
4. What parts can be made with lathes?
5. What units are located on the bed?
6. How is the workpiece clamped in a lathe?
7. What operations can lathes do?
3. Match the words and their Russian equivalents:
1) countershaft задняя бабка
2) spanner фартук
3) collet каретка
4) screw cutting передняя бабка
5) headstock контрпривод; промежуточный вал
6) tailstock гаечный ключ
7) saddle нарезание винтов
8) lever рычаг
9) apron рукоятка
10) carriage станина
11) bed цанга; зажимная втулка,
12) handle суппорт
4. Fill in the gaps with prepositions:
1. Hundreds … varieties … metal machine tools ranging … size, are
used … modern industry.
2. The engine lathe is considered the father … all other machine tools
… many … its fundamental mechanical elements are incorporated … the
design … other machine tools.
3. Boring mills have circular horizontal tables that rotate … a vertical
axis and they are designed … boring and turning operations … parts that
are too large to be mounted … a lathe.
4. The spindle is the part … the machine … which power is applied to
rotate the work.
5. Some planers can machine parts … … 50 feet long.
18
5. Translate sentences from Russian into English.
1. Токарный станок остаётся самым важным станком.
2. Все остальные токарные станки оборудованы электроприводом.
3. Движение инструмента контролируется с высокой точностью.
4. Электропривод позволяет обрабатывать заготовку на разных
скоростях.
5. Прецизионные токарные станки с задней передачей включают
в себя: станину с крепёжными болтами, разъемное цанговое устройство и т.д.
Vocabulary
1) drill bit
сверло, головка бура
2) workbench
слесарная обработка
3) to feed
питать, снабжать
4) a countersink
зенковка, конический зенкер
5) pilot hole
направляющее отверстие
6) a guidance
руководство, управление
7) a clearance
допуск (разрешённое отклонение от
положенного значения величины)
8) a jobber
сдельщик
9) a friction
трение
10) a shank
хвостовик, тело (болта, заклепки)
11) canned
закупоренный, герметизированный
12) to embed
заделывать, заливать, монтировать,
погружать
13) to traverse
продольная подача, двигаться
в поперечном направлении
14) cone pulley
ступенчатый шкив, барабан
15) call up
вызов, подача сигнала
19
Text 2.
DRILLING MACHINES AND OPERTIONS WITH THEM
Drilling machine is a machine for rotating a drill bit and for providing
the axial force necessary for feeding the drill into the material being
drilled. Bench of drilling machine is a small machine for mounting on a
workbench having a sensitive hand-feed mechanism and the facility to
change the spindle speed by means of cone pulleys.
The center drill is a tool used by a lathe or a drilling machine for drilling holes in the ends of a workpiece prior to turning between centers. The
center drill produces a 60° countersink with a small pilot hole in the bot-
tom. The lathe center supports the work on its conical surface but not on
its tip.
Twist drill is a tool that rotates to cut holes. The lands are – narrow
strips along the cutting edges of the flutes to provide guidance with
minimum friction and it is the diameter across them that is accurately
ground to size. The flutes provide the correct cutting angle and clearance for waste material to flow from the hole. The rake angle (helix angle of the flutes) can vary according to the material to be cut, but the
standard angle of a general purpose “jobber” drill is 25-30°, the clear-
ance angle is 10-12°, and the point angle is 118°. The diameter of the
body tapes slightly (becomes smaller) towards the shank end to provide
clearance.
Canned cycles. These are standard fixed cycles that save the need for
repetitive programming of common operations. The sequence of events for
a standard cycle is embedded in the memory of the controller's computer at
the time of manufacture and is called up, when required, by an appropriate
G-code. For example, G81 calls up the drilling cycle where the sequence
of events, is rapid traverse to first hole, rapid traverse to clearance plane
height, feed to depth of hole, rapid traverse out to clearance plane
height, rapid traverse to next hole where it is repeated for as many holes as
required.
20
1. Describe how the drilling machine works.
https://smithy.com/machining-handbook/chapter-6/page/1
2. Answer the following questions:
1. What is a drilling machine?
2. What typical drilling machines do you know?
3. What type of the drilling machine is used to change the spindle
speed?
4. What is a gear box used for?
5. Is the center drill a tool or a machine?
6. What tool rotates to cut holes?
7. Why does the diameter of the body tape slightly?
8. What are standard fixed cycles used for?
3. Match the words and their Russian equivalents:
1) cone pulley желоб, паз
2) to elevate трение
21
3) countersink управление
4) shank ступенчатый шкив
5) flute допуск
6) guidance поднимать, улучшать
7) a friction подача сигнала
8) pilot hole зенковка
9) call up хвостовик, тело
10) a clearance направляющее отверстие
4. Translate sentences from English into Russian.
1. A gear box or variable speed electric motor is used to vary the
spindle speed and a power feed facility is provided in addition to manual feed.
2. The sequence of events for a standard cycle is embedded in the
memory of the controller’s computer at the time of manufacture and is
called up when required by an appropriate G-code.
3. The radial arm can be raised or lowered on the column and the drill
head can be traversed to or from the column along the arm.
4. These machines are used when it is not convenient to move the
work in order to position it under the drill.
5. An all-geared drill head with power feed is mounted on an arm that
in turn can be swung about a vertical column.
5. Fill the gaps with the verbs from the box in the right form.
to vary to traverse to ensure to provide to embed to tape
1. The drill head can be … to or from the column along the arm.
2. The flutes … the correct cutting angle and clearance.
3. A gear box is used … the spindle speed.
4. The sequence of events for a standard cycle … in the memory of
the controller’s computer.
5. A small pilot hole in the bottom which … the work on the conical
surface.
6. The diameter of the body … slightly towards the shank end.
Соседние файлы в предмете [НЕСОРТИРОВАННОЕ]