Е. С. Закирова, П. А. Красавин Английский язык для технических вузов
Exercise 9. Make up your own sentences according to the models
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- READING Exercise 10. Read the text, try to focus on its essential facts and choose the most suitable heading given below for each paragraph.
- CUTTING AND JOINING PROCESSES
| Exercise 9. Make up your own sentences according to the models.
Model A : Turning is a cutting process. It produces a cylindrical surface. Being a cutting process, turning produces a cylindrical surface. 1. Milling is a comparatively complex process. It forms the final part. 2. An oxy-fuel cutting torch is a tool for the burning process. It cuts a plate of steel into smaller pieces. 3. A grinding machine is a cutting machine. It produces very fine finishes. 4. A milling machine is a cutting machine. It performs a vast number of complex operations. 5. Chemical milling is an example of a special process. It removes excess material by the use of etching and masking chemicals. Model B: The workpiece which should be turned is rather hard. The workpiece to be turned is rather hard. 1. The metal parts which should be cut are in the foundry. 2. The com- plex operations which should be done embrace slot cutting and threading. 3. A piece of material which should be turned is made of wood or metal. 4. The milling cutter which should be used is rather hard. 5. The cutting tool which should be traversed along two axes of motion produces precise diam- eters and lengths. READING Exercise 10. Read the text, try to focus on its essential facts and choose the most suitable heading given below for each paragraph. 1) Different Kinds of Joining Processes 2) Turning Process 3) Different Kinds of Cutting Processes 4) Milling Process 5) Grinding Machine 6) Different Kinds of Chip Producing Processes CUTTING AND JOINING PROCESSES Besides forming processes, metalworking includes cutting and joining processes. Cutting is considered to be a collection of processes wherein mate- rial is brought to a specified geometry by removing excess material. In cutting metals the excess metal is chips or swarf. Cutting is nearly fully represented by machining, burning, and some special processes. Machining is most com- monly known to be a chip producing process. Drilling a hole in a metal part is the most common example of a chip producing process. Burning is a process during which metal parts are cut into pieces. Using an oxy-fuel cutting torch to separate a plate of steel into smaller pieces is an example of burning. Chemical 164 milling is an example of a special process that removes excess material by the use of etching and masking chemicals. In metalworking a lot of chip producing technological processes are avail- able, such as turning, boring, milling, drilling, grinding, etc. Turning is a cutting process for producing a cylindrical surface. It can be done on a lathe, which frequently requires continuous supervision by the op- erator, or by using modern computer numerical control (CNC) lathes. When turning, a piece of material (wood, metal, plastics, or stone) rotates and a cut- ting tool (usually single-point) is traversed along two axes of motion to produce precise diameters and lengths. Turning can be either on the outside of the cyl- inder or on the inside (also known as boring) to produce tubular components of various sizes. Milling is a comparatively complex process of removing material to form the final part. It is generally done on a milling machine, which includes a mill- ing cutter (usually multipoint) that rotates about its axis, and a worktable that can move in multiple directions. Milling machines can perform a vast number of complex operations, such as slot cutting, planing, drilling, threading, rab- beting, etc. There are two common types of milling machines: the horizontal and vertical mills. A grinding machine is a machine used for producing very fine finishes. As a rule, a grinding machine uses an abrasive wheel as a cutting device to re- move material from the workpiece. It can be made of various sizes and types of stones or inorganic materials. Finished parts that meet specifications are assembled into different kinds of machines. For this purpose, temporary and permanent joining techniques exist. Mechanical fastening, sometimes called temporary mechanical joining, includes joining processes which use bolts, screws, studs, etc. Permanent join- ing processes embrace welding, brazing, soldering, and riveting. жүктеу/скачать 4,38 Mb. Достарыңызбен бөлісу:
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