Stepanova_LM_AM-123_Stanki_Part2_1978-1 (Станки), страница 2

_{lathe - токарный станок}

_{engine lathe - (универсальный; токарно-винторезныя станок}

_{longitudinally - продольно, в продольном направлении}

_{member - элемент (конструкции)}

_{раn - поддон}

_{to position - устанавливать}

_{saddle - салазки}

_{shaft - вал, ось}

_{subassembly - узел}

_{taiistock - задняя бабка}

_{vees - V-образные направляющие.}

_{ways - направляющие (станка)}

_{automatic screw machine - винторезный автомат}

_{cross slide - поперечные салазки суппорта}

_{cutting fluid - смазочно-охлаждающая жидкость}

_{r.р.m. - revolutions per minute - оборотов в минуту}

_{tool post - резцедержатель}

_{train of gears - система (набор) шестерен}

_Exercises.

_{I. Look through the text once more and find equivalents for:}

_{чем на любом другом станке; в зависимости от того, как он укреплен; самые первые типы; много различных операций; как показывает само название; вплоть до; режим работы; смазочно-охлаждающая жидкость; он (резец) подается к заготовке}

_{II. Put the verbs in brackets into Active or Passive and
translate the sentences.}

_{1. The lathe bed is the foundation on which the lathe (tо build).}

_{2. There are two sets of ways on the lathe, the outer way's (to}

_{guide) the carriage, and the inner ways (to keep) the head—}

_{stock and tailstock in line. *}

_{3. The headstock, carriage, and tailstock (to align) parallel to the axis of the spindle through the entire length of the bed.}

1. _{The main spindle (to revolve) on two bearings.}

_{5. The main spindle (to control) the speed of the work when the}

_{work (to revolve).}

_{6. The live centre, which (to fit) into the main spindle, (to}

_{call) so because it (to act) as a bearing surface on which}

_{the work (to rest).}

_{7. The motor and driving mechanism (to enclose) in the cabinet under the lathe headstock.}

1. _{Metal-cutting lathes (to use) to perform a wide variety of operations.}

2. _{The direction and rate at which the tool (to feed) to the work can be changed whenever needed.}

_{III. Read the following text without using a dictionary. Make up a summary of the text.}

_{LATHE PARTS.}

_{The lathe bed is the foundation on which the lathe is built. It must be substantially constructed and scientifically designed. There are two sets of ways on the lathe, the outer ways guide the carriage, and the inner ways keep the headstock and tailstock in line.}

_{Prismatic V ways are the most accurate type of ways for lathe}

_{beds. The V ways of the lathe bed are very carefully machined}

_{so that the headstock, carriage, and tailstock are perfectly}

_{fitted and aligned parallel to the axis of the spindle through the entire length of the bed. The complete headstock comprises}

_{the headstock casting, the main spindle, the necessary mechanim}

_{for obtaining the various spindle speeds, and also certain}

_gears.

_{The main spindle revolves on two bearings}¹_{), one at each}

_{end of the headstock. The main spindle controls the speed of the work when the work revolves. It must be perfectly aligned be­- cause the spindle in imperfect alignment, or with improperly adjusted bearings, will cause trouble. The main spindle is threaded to receive a chuck or faceplate.}

_{The motor and driving mechanism are fully enclosed in the cabinet leg underneath the lathe headstock. There are no exposed pulleys, belts, or gears.}

_{1) Bearing - опора}

_{IV. Answer the questions.}

1. _{What operations can be performed on a lathe?}

_{2. Why were the earliest types of lathes called "engine lathes"?}

_{3. What kind of automatic lathes do you know?}

_{4. What are the principal parts of a lathe?}

_{5. What aligns the headstock and tailstock?}

_{6. What does a chip pan collect?}

_{7. Where is the headstock mounted?}

_{8. What is the function of the train of gears in the headstock?}

_{9. Where is the tailstock mounted?}

_{10.In what direction can the tailstock move? 11.What does the tailstock support?}

_{12.Where is the carriage mounted?}

_{13.What is the function of the carriage?}

_{14.What are its principal parts?}

_{V. Retell the text.}

_{§3. THE MILLING MACHINE}

_{The milling machine is a machine tool in which metal is removed by means of a revolving cutter with many teeth, each tooth having a cutting edge which removes its share of the stock. The work is supported by various methods on the work table, and may be fed to the cutter longitudinally, transversely, or vertically. A great variety of work may be done on a milling machine.}

_{The machines for the milling operations fall into three main classes: 1. Horizontal plain milling machine. 2. Vertical milling machine. 3. Universal milling machine.}

_{In the horizontal milling machine the table with the work mounted on it moves in a longitudinal direction with a recipro­cating motion under the revolving cutter. The table can be raised and lowered, and can also be given a cross traverse mo- tion at right angles to this motion and the motion of the table in the longitudinal direction.}

_{Many improvements have been made in milling machine design, and latest improvements incorporate a dial which calculates the speeds, feeds, and cutter diameters for various materials. Ma­chines incorporating this feature are known as dial-type milling machines.}

_{The dial calculates the correct cutting speed, enabling efficient milling and lengthening the cutter life accordingly. By setting the type of cutter and its diameter in the windows of the dial, the cutting speed and spindle r.p.m. can be read off on the circular scales.}

_{The vertical machine, as its name implies, has a vertical spindle, and apart from this the general principles of the plain horizontal milling machine are applicable here. The table has the same movements of longitudinal traverse, cross traverse, and elevation (raising and lowering). In addition, the cutter mounted on the vertical spindle can also be raised and lowered to suit the work.}

_{The universal milling machine is similar to the plain hori­zontal miller, but in addition has an added table movement which enables the table to be swivelled about its vertical axis. The swivel of the table, usually up to 30°, enables spiral milling or helical milling to be performed, and the table of this type of machine is provided with a dividing head. This latter enables work to be indexed and its circumference to be divided up into any number of divisions.}

_{Words and word combinations to be remembered:}

_{applicable - пригодный, подходящий, применимый cutter - Фреза}

_{dial - лимб, шкала}

_{to divide - делить division - деление}

_{efficient - эффективный, производительный, экономичный}

_{elevation - подъем}

_{to enable - давать возможность}

_{helical - винтовой, спиральный}

_{to index- поворачивать (на определенный угол)}

_{to incorporate - включать (в себя), объединять}

_{to mount - устанавливать, монтировать}

_{to reciprocate - двигаться возвратно - поступательно}

_{to set - устанавливать}

_{stock - материал, заготовка}

_{to swivel - поворачиваться, swivel - поворот}

_{transverse - поперечный}

_{cutter life - срок службы (стойкость) фрезы}

_{dividing head - делительная головка}

_{cross traverse - поперечная подача (перемещение)}

_{longitudinal traverse - продольная подача (перемещение)}

_{work table - рабочий стол (станка)}

_{apart from this - кроме этого}

_{in addition - кроме того}

_Exercises.

_{I. a) Give the verbs corresponding to the following adjectives
and translate them:}

_{low, long, correct, applicable, cross, general, modern, various, suitable.}

_{b) Give the nouns corresponding to the following verbs and}

_{translate them:}

_{to divide, to move, to swivel, to add, to cut, to improve, to design, to direct, to revolve, to operate, to remove, to recip­rocate, to calculate, to elevate.}

_{II. Insert words from your active vocabulary. Translate the
sentences.}

1. _{... enables the operator to calculate the correct cutting speed.}

2. _{The table ... under the revolving cutter.}

_{3. The cutting edge of each tooth removes a certain part of... .}

_{4. ... of the table about its vertical axis ... helical milling
to be performed.}

_{5. The latest designs of milling machines ... dials for calculate-­ ing speeds and feeds.}

_{6. The universal milling machine is provided with a ... ...}

_{which enables the work to be ... and divided up into any}

_{number of ... .}

_{III. Translate the sentences having attention to the modal verbs of obligation.}

_{The production engineers ought to decido what operations are to be performed on the raw material to transform it into the finished product. They should specify the exact sequence in which these operations have to be performed, and the various types of machine tools required for each operation or group of operations. And after they have made up the production plan, they must go farther and design the special work-holding fixtures and tools needed to carry out the plan rapidly and with precision.}

_{IV. Translate the sentences paying attention to the Absolute Participial Construction.}

1. _{The spindel of the drilling machine being modified, the cut-ting tools are fed vertically to the work.}

_{2. The spindel holding the tool in the drilling machine, the}

_{carriage is not needed.}

_{3. Like all other machine tools drilling machines are made in a wide variety of sizes, the mechanical principles of speed and feed changes not differing from those in lathes.}

_{4. The work table being vertically adjustable, various heights of work can be mounted.}

_{5. In drilling machines the work can be seated on the base, with the work table swiveled up to 90°.}

_{V. Answer the questions.}

_{1. By what means is metal removed from the stock on a milling
machine?}

<sub>2. In what directions can the work be fed to the cutter?
3. What main classes of milling machines do you know?</sub>

_{4. How does the table in the horizontal milling machine move?}

_{5. What are the latest improvements in the design of milling}

_machines?

_{6. What does the dial enable the operator to do?}

_{7. What is the main difference between the vertical milling}

_{machine and the horizontal one?}

_{8. What kind of milling operations can be performed due to the
swivel of the table?}

_{9. What is the table provided with? and what for?
10.What is the dividing head used for?}

_{VI. Retell the text.}

_{VII. Read the text without using a dictionary. (Some words are given below.) Describe the drilling machine.}

_{A vertical drilling machine is, essentially, a lathe which is arranged so that its tailstock end rests on the floor. The spindle of the machine is modified to hold twist drills and other cutting tools and to move them vertically to feed them to the work. Since the carriage is not needed to hold tools, it is omitted from the construction. And the tailstock is modified so that it becomes a horizontal arm that supports a table for holding the workpieces.}

_{The vertical drilling machine or drill press, has six or more spindle speeds and three or more automatic feeds. The head, which carries the sleeve, spindle, and feed gears, is in many models bolted to the frame and, to accommodate different heights of work, the worktable is vertically adjustable.}