Агабекян - Английский для технических ВУЗов. I. Гласные звуки i, i. II. Text A About myself, Text B My Biography
Скачать 1.14 Mb.
|
Text В: «TYPES OF AUTOMATION»Applications of Automation and Robotics in Industry Manufacturing is one of the most important application area for automation technology. There are several types of automation in manufacturing. The examples of automated systems used in manufacturing are described below. 1. Fixed automation, sometimes called «hard automation» refers to automated machines in which the equipment configuration allows fixed sequence of processing operations. These machines are programmed by their design to make only certain processing operations. They are not easily changed over from one product style to another. This form of automation needs high initial investments and high production rates. That is why it is suitable for products that are made in large volumes. Examples of fixed automation are machining transfer lines found in the automobile industry, automatic assembly machines and certain chemical processes. 2. Programmable automation is a form of automation for producing products in large quantities, ranging from several dozen to several thousand units at a time. For each new product the production equipment must be reprogrammed and changed over. This reprogramming and changeover take a period of non-productive time. Production rates in programmable automation are generally lower than in fixed automation, because the equipment is designed to facilitate product changeover rather than for product specialization. A numerical-control machine-tool is a good example of programmable automation. The program is coded in computer memory for each different product style and the machine-tool is controlled by the computer programme. 3. Flexible automation is a kind of programmable automation. Programmable automation requires time to re-program and change over the production equipment for each series of new product. This is lost production time, which is expensive. In flexible automation the number of products is limited so that the changeover of the equipment can be done very quickly and automatically. The reprogramming of the equipment in flexible automation is done at a computer terminal without using the production equipment itself. Flexible automation allows a mixture of different products to be produced one right after another. Vocabularyequipment — оборудование sequence — последовательность initial — первоначальный, начальный investment — инвестиция, вклад to facilitate — способствовать rate — скорость, темп assembly machines — сборочные машины quantity — количество non-productive — непроизводительный changeover — переход, переналадка General understanding: 1. What is the most important application of automation? 2. What are the types of automation used in manufacturing? 3. What is fixed automation? 4. What are the limitations of hard automation? 5. What is the best example of programmable automation? 6. What are the limitations of programmable automation? 7. What are the advantages of flexible automation? 8. Is it possible to produce different products one after another using automation technology? Exercise 7.2. Find equivalents in English in the text: 1. сфера применения 2. фиксированная последовательность операций 3. автоматические сборочные машины 4. определенные химические процессы 5. станок с числовым программным управлением 6. потерянное производственное время 7. разнообразная продукция Exercise 7.3. Explain in English what does the following mean? 1. automation technology 2. fixed automation 3. assembly machines 4. non-productive time 5. programmable automation 6. computer terminal 7. numerical-control machine-tool Text C: «ROBOTS IN MANUFACTURING»Today most robots are used in manufacturing operations. The applications of robots can be divided into three categories: 1. material handling 2. processing operations 3. assembly and inspection. Material-handling is the transfer of material and loading and unloading of machines. Material-transfer applications require the robot to move materials or work parts from one to another. Many of these tasks are relatively simple: robots pick up parts from one conveyor and place them on another. Other transfer operations are more complex, such as placing parts in an arrangement that can be calculated by the robot. Machine loading and unloading operations utilize a robot to load and unload parts. This requires the robot to be equipped with a grip-per that can grasp parts. Usually the gripper must be designed specifically for the particular part geometry. In robotic processing operations, the robot manipulates a tool to perform a process on the work part. Examples of such applications include spot welding, continuous arc welding and spray painting. Spot welding of automobile bodies is one of the most common applications of industrial robots. The robot positions a spot welder against the automobile panels and frames to join them. Arc welding is a continuous process in which robot moves the welding rod along the welding seam. Spray painting is the manipulation of a spray-painting gun over the surface of the object to be coated. Other operations in this category include grinding and polishing in which a rotating spindle serves as the robot's tool. The third application area of industrial robots is assembly and inspection. The use of robots in assembly is expected to increase because of the high cost of manual labour. But the design of the product is an important aspect of robotic assembly. Assembly methods that are satisfactory for humans are not always suitable for robots. Screws and nuts are widely used for fastening in manual assembly, but the same operations are extremely difficult for an one-armed robot. Inspection is another area of factory operations in which the utilization of robots is growing. In a typical inspection job, the robot positions a sensor with respect to the work part and determines whether the part answers the quality specifications. In nearly all industrial robotic applications, the robot provides a substitute for human labour. There are certain characteristics of industrial jobs performed by humans that can be done by robots: 1. the operation is repetitive, involving the same basic work motions every cycle, 2. the operation is hazardous or uncomfortable for the human worker (for example: spray painting, spot welding, arc welding, and certain machine loading and unloading tasks), 3. the workpiece or tool is too heavy and difficult to handle, 4. the operation allows the robot to be used on two or three shifts. Vocabulary: handling — обращение transfer — передача, перенос location — местонахождение pick up — брать, подбирать arrangement — расположение to utilize — утилизировать, находить применение gripper — захват to grasp — схватывать spot welding — точечная сварка continuous — непрерывный arc welding — электродуговая сварка spray painting — окраска распылением frame — рама spray-painting gun — распылитель краски grinding — шлифование polishing — полирование spindle — шпиндель manual — ручной labour — труд hazardous — опасный shift — смена General understanding: 1. How are robots used in manufacturing? 2. What is «material handling»? 3. What does a robot need to be equipped with to do loading and unloading operations? 4. What does robot manipulate in robotic processing operation? 5. What is the most common application of robots in automobile manufacturing? 6. What operations could be done by robot in car manufacturing industry? 7. What are the main reasons to use robots in production? 8. How can robots inspect the quality of production? 9. What operations could be done by robots in hazardous or uncomfortable for the human workers conditions? Exercise 7.4. Translate into English: 1. Существует несколько различных сфер использования автоматизации в производстве. 2. Для использования жесткой автоматизации необходимы большие инвестиции. 3. Жесткая автоматизация широко используется в химической промышленности. 4. Станки с числовым программным управлением — хороший пример программируемой автоматизации. 5. Гибкая автоматизация делает возможным перепрограммирование оборудования. 6. Время простоя оборудования оборачивается большими убытками. 7. Использование гибкой автоматизации делает возможным производство разнообразной продукции. FAMOUS PEOPLE OF SCIENCE AND ENGINEERING James Watt James Watt was a Scottish inventor and mechanical engineer, known for his improvements of the steam engine. Watt was born on January 19, 1736, in Greenock, Scotland. He worked as a mathematical-instrument maker from the age of 19 and soon became interested in improving the steam engine which was used at that time to pump out water from mines. Watt determined the properties of steam, especially the relation of its density to its temperature and pressure, and designed a separate condensing chamber for the steam engine that prevented large losses of steam in the cylinder. Watt's first patent, in 1769, covered this device and other improvements on steam engine. At that time. Watt was the partner of the inventor John Roebuck, who had financed his researches. In 1775, however. Roebuck's interest was taken over by the manufacturer Matthew Boulton, owner of the Soho Engineering Works at Birmingham, and he and Watt began the manufacture of steam engines. Watt continued his research and patented several other important inventions, including the rotary engine for driving various types of machinery; the double-action engine, in which steam is admitted alternately into both ends of the cylinder; and the steam indicator, which records the steam pressure in the engine. He retired from the firm in 1800 and thereafter devoted himself entirely to research work. The misconception that Watt was the actual inventor of the steam engine arose from the fundamental nature of his contributions to its development. The centrifugal or flyball governor, which he invented in 1788, and which automatically regulated the speed of an engine, is of particular interest today. It embodies the feedback principle of a servomechanism, linking output to input, which is the basic concept of automation. The watt, the unit of power, was named in his honour. Watt was also a well-known civil engineer. He invented, in 1767, an attachment that adapted telescopes for use in the measurement of distances. Watt died in Heathfield, near Birmingham, in August 1819. |