2023年全國碩士研究生考試考研英語一試題真題(含答案詳解+作文范文)_第1頁
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1、<p><b>  英文翻譯</b></p><p>  工業(yè)機械手可以代替人手的繁重勞動,顯著減輕工人的勞動強度,提高 勞動生產(chǎn)率和自動化水平。工業(yè)生產(chǎn)中經(jīng)常出現(xiàn)的笨重工件的搬運和長期頻繁,單調的操作,如果沒有機械手那么工人的勞動強度是很高的,有時候還要用行車員工件,生產(chǎn)速度大大延緩,這種情況采用機械手是很有效的。此外,它能在高溫、低溫、深水、宇宙、反射性和其他有毒、有污染環(huán)境條

2、件上進行操作。更顯其優(yōu)越性,有著廣闊的發(fā)展前途。</p><p>  可編程控制器是60年代末在美國首先出現(xiàn),當時叫可編程邏輯控制器PLC(Programmable Logic Controller),目的是用來取代繼電器,以執(zhí)行邏輯判斷、計時、計數(shù)等順序控制功能。PLC的基本設計思想是把計算機功能完善、靈活、通用等優(yōu)點和繼電器控制系統(tǒng)的簡單易懂、操作方便、價格便宜等優(yōu)點結合起來,控制器的硬件是標準的、通用的。根

3、據(jù)實際應用對象,將控制內(nèi)容編成軟件寫入控制器的用戶程序存儲器內(nèi)??刂破骱捅豢貙ο筮B接方便。 隨著半導體技術,尤其是微處理器和微型計算機技術的發(fā)展,到70年代中期以后,PLC已廣泛地使用微處理器作為中央處理器,輸入輸出模塊和外圍電路也都采用了中、大規(guī)模甚至超大規(guī)模的集成電路,這時的PLC已不再是邏輯判斷功能,還同時具有數(shù)據(jù)處理、PID調節(jié)和數(shù)據(jù)通信功能。 可編程控制器是一種數(shù)字運算操作的電子系統(tǒng),專為在工業(yè)環(huán)境下應用而

4、設計。它采用了可編程序的存儲器,用來在其內(nèi)部存儲執(zhí)行邏輯運算,順序控制、定時、計算和算術運算等操作的指令,并通過數(shù)字式和模擬式的輸入輸出,控制各種類型的機械或生產(chǎn)過程。PLC是微機技術與傳統(tǒng)的繼電接觸控制技術相結合</p><p>  氣動技術是以壓縮空氣為介質來傳動和控制機械的一門專業(yè)技術。由于它具有節(jié)能、無污染、高效、低成本、安全可靠、結構簡單等優(yōu)點,廣泛應用于各種機械和生產(chǎn)線上。過去汽車、拖拉機等生產(chǎn)線上的

5、氣動系統(tǒng)及其元件,都由各廠自行設計、制造和維修。 </p><p>  氣動技術應用面的擴大是氣動工業(yè)發(fā)展的標志。氣動元件的應用主要為兩個方面:維修和配套。過去國產(chǎn)氣動元件的銷售要用于維修,近幾年,直接為主要配套的銷售份額逐年增加。國產(chǎn)氣動元件的應用,從價值數(shù)千萬元的冶金設備到只有1~2百元的椅子。鐵道扳岔、機車輪軌潤滑、列車的煞車、街道清掃、特種車間內(nèi)的起吊設備、軍事指揮車等都用上了專門開發(fā)的國產(chǎn)氣動元件

6、。這說明氣動技術已“滲透”到各行各業(yè),并且正在日益擴大。 </p><p>  我國的氣動工業(yè)雖然達到了一定規(guī)模與技術水平,但是與國際先進水平相比,差距甚大。我國氣動產(chǎn)品產(chǎn)值只占世界總產(chǎn)值的1.3%,僅為美國的1/21,日本的1/15,德國的1/8。這與10多億人口的大國很不相稱。從品種上看,日本一家公司有6500個品種,我國只有它的1/5。產(chǎn)品性能和質量水平的差距也很大。 </p><p&g

7、t;  由于氣動技術越來越多地應用于各行業(yè)的自動裝配和自動加工小件、特殊物品的設備上,原有傳統(tǒng)的氣動元件性能正在不斷提高,同時陸續(xù)開發(fā)出適應市場要求的新產(chǎn)品,使氣動元件的品種日益增加,其發(fā)展趨勢主要有以下幾個方面: </p><p>  體積更小,重量更輕,功耗更低.在電子元件、藥品等制造行業(yè)中,由于被加工件體積很小,勢必限制了氣動元件的尺寸,小型化、輕型化是氣動元件的第一個發(fā)展方向。國外已開發(fā)了僅大姆指大小、有

8、效截面積為0.2mm2的超小型電磁閥。能開發(fā)出外形尺寸小而流量較大的元件更為理想。為此,相同外形尺寸的閥,流量已提高2~3.3倍。有一種系列的小型電磁閥,其閥體寬僅10mm,有效面積可達5mm2;寬15mm,有效面積達10mm2等。 </p><p>  國外電磁閥的功耗已達0.5W,還將進一步降低,以適應與微電子相結合。 </p><p>  氣源處理組合件,國內(nèi)外大多采用了積木式的砌塊

9、結構,不僅尺寸緊湊,而且結合、維修都很方便。 </p><p>  執(zhí)行元件的定位精度提高,剛度增加,活塞桿不回轉,使用更方便.為了提高氣缸的定位精度,附帶制動機構和伺服系統(tǒng)的氣缸應用越來越普遍。帶伺服系統(tǒng)的氣缸,即使供氣壓力和所負的載荷變化,仍可獲得±0.1mm的定位精度。 </p><p>  在國際展覽會上,各種異型截面缸筒和活塞桿的氣缸甚多,這類氣缸由于活塞桿不會回轉,應

10、用在主機上時,無須附加導向裝置即可保持一定精度。此外還開發(fā)了不少帶各種導向機構的氣缸和氣缸滑動組件,例如具有兩根導向桿的氣缸、雙活塞桿雙缸筒氣缸等。 </p><p>  氣缸筒外形已不限于圓形、而是方形、米字形或其它形狀,在型材上開了導向槽、傳感器和開關的安裝槽等,讓用戶安裝使用更方便。 </p><p>  多功能化,復合化.為了方便用戶,適應市場的需要開發(fā)了各種由多只氣動元件組合并配

11、有控制裝置的小型氣動系統(tǒng)。如用于移動小件物品的組件,是將帶導向器的兩只氣缸分別按X軸和Z軸組合而成。該組件可搬動3kg重物,配有電磁閥、程控器,結構緊湊,占有空間小,行程可調整。又如一種上、下料模塊,有七種不同功能的模塊形式,能完成精密裝配線上的上、下料作業(yè),可按作業(yè)內(nèi)容將不同模塊任意組合。還有一種機械手是由外形小并能改變擺動角度的擺動氣缸與夾頭的組合件,夾頭部位有若干種夾頭可選配。 </p><p>  與電子

12、技術結合,大量使用傳感器,氣動元件智能化.帶開關的氣缸國內(nèi)已普遍使用,開關體積將更小,性能更高,可嵌入氣缸缸體;有些還帶雙色顯示,可顯示出位置誤差,使系統(tǒng)更可靠。用傳感器代替流量計、壓力表、能自動控制壓縮空氣的流量、壓力,可以節(jié)能并保證使用裝置正常運行。氣動伺服定位系統(tǒng)已有產(chǎn)品進入市場。該系統(tǒng)采用三位五通氣動伺服閥,將預定的定位目標與位置傳感器的檢測數(shù)據(jù)進行比較,實施負反饋控制。氣缸最大速度達2m/s、行程300mm時,系統(tǒng)定位精度&#

13、177;0.1mm。日本試制成功一種新型智能電磁閥,這種閥配帶有傳感器的邏輯回路,是氣動元件與光電子技術結合的產(chǎn)物。它能直接接受傳感器的信號,當信號滿足指定條件時,不必通過外部控制器,即可自行完成動作,達到控制目的。它已經(jīng)應用在物體的傳送帶上,能識別搬運物體的大小,使大件直接下送,小件分流。 </p><p>  更高的安全性和可靠性.從近幾年的氣動技術國際標準可知,標準不僅提出了互換性要求,并且強調了安全性。管

14、接頭、氣源處理外殼等耐壓試驗的壓力提高到使用壓力的4~5倍,耐壓時間增加到5~15min,還要在高、低溫度下進行試驗。如果貫徹這些國際標準,國內(nèi)的缸筒、端蓋、氣源處理鑄件和管接頭等都難達到標準要求。除耐壓試驗處,結構上也作了某些規(guī)定,如氣源處理的透明殼外部規(guī)定要加金屬防護罩。</p><p>  Industrial robots can replace the hands of heavy labor, sig

15、nificantly reduce labor intensity, and improve labor productivity and automation level. Industrial production often appears in the heavy work frequently, handling and long-term operation, if not drab robots that labor in

16、tensity is high, sometimes even with employees, driving speed greatly retard, this kind of circumstance using manipulator is very effective. In addition, it can be in high temperature, low temperature, water, the univers

17、e</p><p>  Programmable controller is at the end of the 60's first appeared in the United States, when called programmable logic controller PLC (Programmable Logic Controller), the purpose is to replace

18、the relay in order to determine the implementation of the logic, timing, counting, such as sequence control functions. PLC basic design idea is to improve the computer function, flexible, general-purpose relays, etc. and

19、 control system for easy-to-read, easy to operate, cheap to combine the advantages of th</p><p>  As the semiconductor technology, especially in microprocessors and micro-computer technology, to the mid-70s

20、after, PLC has been the widespread use of microprocessors as the central processing unit, input and output modules, and peripheral circuits are also used in large-scale ultra-large-scale integrated circuits even when the

21、 PLC is no longer determine the function of logic, but also at the same time data processing, PID regulation and data communication functions. </p><p>  Programmable controller is a digital electronic comput

22、ing operating system, designed for applications in industrial environments designed. It uses a programmable memory for storage in its internal implementation of logic operations, sequence control, timing, calculation and

23、 arithmetic operations, such as operating instructions, and through digital and analog input and output, control of various types of machinery or production process. PLC is a computer technology and traditional technolog

24、y of r</p><p>  User-programmable controller is a non-contact equipment, changes in procedures to change the production process, it can be selected in the preliminary design stage programmable controller, id

25、entified in the implementation stage process. On the other hand, manufacturing production from the makers of programmable controller point of view, in the manufacturing phase of the order does not require the user reques

26、t in accordance with specially designed controllers, suitable for mass production. Becaus</p><p>  Pneumatic technology for the medium is compressed air to drive and control a mechanical expertise. Because o

27、f its energy-saving and pollution-free, highly efficient, low-cost, safe and reliable, the advantages of simple structure, a wide range of machinery and production lines. Over the past cars, tractors and other production

28、 line pneumatic system and its components, both by the plant to the design, manufacture and maintenance. </p><p>  Pneumatic technology applications is the aerodynamic surface of the expansion of a symbol of

29、 industrial development. Application of pneumatic components for the two main areas: maintenance and support. Past sales of Chinese-made pneumatic components to be used for maintenance, in recent years, as the main suppo

30、rting direct sales has increased year by year. Domestic Application of pneumatic components, tens of millions of dollars from the value of the metallurgical equipment that only 1 to 2 hund</p><p>  Although

31、China's air industry has reached a certain scale and technical level, but with the international advanced level compared to the large gap. Pneumatic products output value of China's GDP accounted for only 1.3% of

32、 the world, only the United States, 1 / 21, Japan's 1 / 15, Germany 1 / 8. This is more than 10 million people does not match the big country. From the species, the Japanese company have 6500 species, it is China'

33、;s only 1 / 5. The level of product performance and quality gap is </p><p>  More and more as a result of aerodynamic technologies used in various industries and automatic processing of automatic assembly of

34、 small pieces of equipment, special items, the original performance of the traditional pneumatic components is increasing at the same time have to adapt to market requirements to develop new products so that the varietie

35、s of pneumatic components increasing trend of their development in the following areas: </p><p>  Smaller and lighter weight, lower power consumption. In electronic components, pharmaceuticals and other manu

36、facturing industries, because of the size of a small piece to be machined, it is bound to limit the size of pneumatic components, small size, light is the pneumatic components The first direction of development. Have bee

37、n developed abroad, just thumb the size of 0.2mm2 effective cross-sectional area for the ultra-compact solenoid valve. Able to issue a size small and a better flow of larg</p><p>  Solenoid valve power consu

38、mption abroad than 0.5W, will be further reduced in order to adapt to the combination and Microelectronics. </p><p>  Gas source processing assembly, both at home and abroad using a building-block most of th

39、e block structure, not only the size of a compact, but with very easy maintenance. </p><p>  Implementation of components to improve the positioning accuracy, stiffness increased, non-rotating piston rod, th

40、e use of more convenient. In order to improve the positioning accuracy of the cylinder, with brake servo system and the increasing application of the cylinder. Servo system with the cylinder, even if the gas pressure and

41、 the negative changes in the load can still receive the positioning accuracy of ± 0.1mm. </p><p>  In the international exhibition, a variety of special-shaped cross-section cylinder and the cylinder pi

42、ston rod a lot, as a result of this type of cylinder piston rod will not turn, used in the host without additional device-oriented to maintain a certain accuracy. In addition, a number of development-oriented institution

43、s with a variety of cylinder and cylinder sliding components, such as with a two-under-oriented cylinder, double cylinder such as cylinder piston rod double. </p><p>  Cylinder tube has not limited to a circ

44、ular shape, but square, rice-shaped or other shape, in profile slot on the set-oriented, sensors and switches such as the installation of slot to enable users to install more convenient to use. </p><p>  Mul

45、ti-function, and composite. For the convenience of users, to adapt to the needs of the market has developed more than a variety of pneumatic components by the combination of control devices with a small pneumatic system.

46、 Such as small items for mobile components, is the band director, respectively, according to the two-cylinder X-axis and Z-axis combination. The movable components 3kg weights with Solenoid Valve, program-controlled devi

47、ce, compact structure, occupy space, adjustable travel. A</p><p>  And electronic technology, large-scale use of sensors, intelligent pneumatic components. With switch has been the widespread use of domestic

48、 cylinders, switch size will be smaller, higher performance can be embedded in the cylinder block; some with two-color display can be shows the location of the error, making the system more reliable. Replace the flow met

49、er sensors, pressure gauges, automatic control of compressed air can flow, pressure, can use energy-saving devices and to ensure normal oper</p><p>  Higher safety and reliability. From pneumatic technology

50、in recent years, international standards, we can see that the standard not only the interchangeability requirements and stressed the importance of security. Pipe joints, gas shells, such as the source of pressure to deal

51、 with the pressure of the pilot pressure to the 4 to 5 times the pressure of time to 5 ~ 15min, but also in the high-and low-temperature test. If you implement these international standards, domestic cylinder tube, end c

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