核桃去殼機的設計
核桃去殼機的設計,核桃,去殼,設計
附錄A
機械工程的發(fā)展歷程及展望
人類成為“現(xiàn)代人”的標志就是制造工具。石器時代的各種石斧、石錘和木質、皮質的簡單粗糙的工具是后來出現(xiàn)的機械的先驅。從制造簡單工具演進到制造由多個零件、部件組成的現(xiàn)代機械,經(jīng)歷了漫長的過程。
??? 幾千年前,人類已創(chuàng)制了用于谷物脫殼和粉碎的臼和磨,用來提水的桔槔和轆轤,裝有輪子的車,航行于江河的船及槳、櫓、舵等。所用的動力,從人自身的體力,發(fā)展到利用畜力、水力和風力。所用材料從天然的石、木、土、皮革,發(fā)展到人造材料。最早的人造材料是陶瓷,制造陶瓷器皿的陶車,已是具有動力、傳動和工作三個部分的完整機械。
??? 人類從石器時代進入青銅時代,再進而到鐵器時代,用以吹旺爐火的鼓風器的發(fā)展起了重要作用。有足夠強大的鼓風器,才能使冶金爐獲得足夠高的爐溫,才能從礦石中煉得金屬。在中國,公元前1000~前900年就已有了冶鑄用的鼓風器,并逐漸從人力鼓風發(fā)展到畜力和水力鼓風。
??? 15~16世紀以前,機械工程發(fā)展緩慢。但在以千年計的實踐中,在機械發(fā)展方面還是積累了相當多的經(jīng)驗和技術知識,成為后來機械工程發(fā)展的重要潛力。17世紀以后,資本主義在英、法和西歐諸國出現(xiàn),商品生產(chǎn)開始成為社會的中心問題。
??? 18世紀后期,蒸汽機的應用從采礦業(yè)推廣到紡織、面粉、冶金等行業(yè)。制作機械的主要材料逐漸從木材改用更為堅韌,但難以用手工加工的金屬。機械制造工業(yè)開始形成,并在幾十年中成為一個重要產(chǎn)業(yè)。
??? 機械工程通過不斷擴大的實踐,從分散性的、主要依賴匠師們個人才智和手藝的一種技藝,逐漸發(fā)展成為一門有理論指導的、系統(tǒng)的和獨立的工程技術。機械工程是促成18~19世紀的工業(yè)革命,以及資本主義機械大生產(chǎn)的主要技術因素。
??? 動力是發(fā)展生產(chǎn)的重要因素。17世紀后期,隨著各種機械的改進和發(fā)展,隨著煤和金屬礦石的需要量的逐年增加,人們感到依靠人力和畜力不能將生產(chǎn)提高到一個新的階段。
??? 在英國,紡織、磨粉等產(chǎn)業(yè)越來越多地將工場設在河邊,利用水輪來驅動工作機械。但當時的煤礦、錫礦、銅礦等礦井中的地下水,仍只能用大量畜力來提升和排除。在這樣的生產(chǎn)需要下,18世紀初出現(xiàn)了紐科門的大氣式蒸汽機,用以驅動礦井排水泵。但是這種蒸汽機的燃料消耗率很高,基本上只應用于煤礦。
??? 1765年,瓦特發(fā)明了有分開的冷凝器的蒸汽機,降低了燃料消耗率。1781年瓦特又創(chuàng)制出提供回轉動力的蒸汽機,擴大了蒸汽機的應用范圍。蒸汽機的發(fā)明和發(fā)展,使礦業(yè)和工業(yè)生產(chǎn)、鐵路和航運都得以機械動力化。蒸汽機幾乎是19世紀唯一的動力源,但蒸汽機及其鍋爐、凝汽器、冷卻水系統(tǒng)等體積龐大、笨重,應用很不方便。
??? 19世紀末,電力供應系統(tǒng)和電動機開始發(fā)展和推廣。20世紀初,電動機已在工業(yè)生產(chǎn)中取代了蒸汽機,成為驅動各種工作機械的基本動力。生產(chǎn)的機械化已離不開電氣化,而電氣化則通過機械化才對生產(chǎn)發(fā)揮作用。
??? 發(fā)電站初期應用蒸汽機為原動力。20世紀初期,出現(xiàn)了高效率、高轉速、大功率的汽輪機,也出現(xiàn)了適應各種水利資源的水輪機,促進了電力供應系統(tǒng)的蓬勃發(fā)展。
??? 19世紀后期發(fā)明的內(nèi)燃機經(jīng)過逐年改進,成為輕而小、效率高、易于操縱、并可隨時啟動的原動機。它先被用以驅動沒有電力供應的陸上工作機械,以后又用于汽車、移動機械和輪船,到20世紀中期開始用于鐵路機車。蒸汽機在汽輪機和內(nèi)燃機的排擠下,已不再是重要的動力機械。內(nèi)燃機和以后發(fā)明的燃氣輪機、噴氣發(fā)動機的發(fā)展,是飛機、航天器等成功發(fā)展的基礎技術因素之一。
??? 工業(yè)革命以前,機械大都是木結構的,由木工用手工制成。金屬(主要是銅、鐵)僅用以制造儀器、鎖、鐘表、泵和木結構機械上的小型零件。金屬加工主要靠機匠的精工細作,以達到需要的精度。蒸汽機動力裝置的推廣,以及隨之出現(xiàn)的礦山、冶金、輪船、機車等大型機械的發(fā)展,需要成形加工和切削加工的金屬零件越來越多,越來越大,要求的精度也越來越高。應用的金屬材料從銅、鐵發(fā)展到以鋼為主。
??? 機械加工包括鍛造、鍛壓、鈑金工、焊接、熱處理等技術及其裝備,以及切削加工技術和機床、刀具、量具等,得到迅速發(fā)展,保證了各產(chǎn)業(yè)發(fā)展生產(chǎn)所需的機械裝備的供應。
??? 社會經(jīng)濟的發(fā)展,對機械產(chǎn)品的需求猛增。生產(chǎn)批量的增大和精密加工技術的進展,促進了大量生產(chǎn)方法的形成,如零件互換性生產(chǎn)、專業(yè)分工和協(xié)作、流水加工線和流水裝配線等。
??? 簡單的互換性零件和專業(yè)分工協(xié)作生產(chǎn),在古代就已出現(xiàn)。在機械工程中,互換性最早體現(xiàn)在莫茨利于1797年利用其創(chuàng)制的螺紋車床所生產(chǎn)的螺栓和螺帽。同時期,美國工程師惠特尼用互換性生產(chǎn)方法生產(chǎn)火槍,顯示了互換性的可行性和優(yōu)越性。這種生產(chǎn)方法在美國逐漸推廣,形成了所謂“美國生產(chǎn)方法”。
??? 20世紀初期,福特在汽車制造上又創(chuàng)造了流水裝配線。大量生產(chǎn)技術加上泰勒在19世紀末創(chuàng)立的科學管理方法,使汽車和其他大批量生產(chǎn)的機械產(chǎn)品的生產(chǎn)效率很快達到了過去無法想象的高度。
??? 20世紀中、后期,機械加工的主要特點是:不斷提高機床的加工速度和精度,減少對手工技藝的依賴;提高成形加工、切削加工和裝配的機械化和自動化程度;利用數(shù)控機床、加工中心、成組技術等,發(fā)展柔性加工系統(tǒng),使中小批量、多品種生產(chǎn)的生產(chǎn)效率提高到近于大量生產(chǎn)的水平;研究和改進難加工的新型金屬和非金屬材料的成形和切削加工技術。
??? 18世紀以前,機械匠師全憑經(jīng)驗、直覺和手藝進行機械制作,與科學幾乎不發(fā)生聯(lián)系。到18~19世紀,在新興的資本主義經(jīng)濟的促進下,掌握科學知識的人士開始注意生產(chǎn),而直接進行生產(chǎn)的匠師則開始學習科學文化知識,他們之間的交流和互相啟發(fā)取得很大的成果。在這個過程中,逐漸形成一整套圍繞機械工程的基礎理論。
??? 動力機械最先與當時的先進科學相結合。蒸汽機的發(fā)明人薩弗里、瓦特,應用了物理學家帕潘和布萊克的理論;在蒸汽機實踐的基礎上,物理學家卡諾、蘭金和開爾文建立起一門新的科學——熱力學。內(nèi)燃機的理論基礎是法國的羅沙在1862年創(chuàng)立的;1876年奧托應用羅沙的理論,徹底改進了他原來創(chuàng)造的粗陋笨重、噪聲大、熱效率低的內(nèi)燃機而奠定了內(nèi)燃機的地位。其他如汽輪機、燃氣輪機、水輪機等都在理論指導下得到發(fā)展,而理論也在實踐中得到改進和提高。
??? 早在公元前,中國已在指南車上應用復雜的齒輪系統(tǒng),在被中香爐中應用了能永保水平位置的十字轉架等機件。古希臘已有圓柱齒輪、圓錐齒輪和蝸桿傳動的記載。但是,關于齒輪傳動瞬時速比與齒形的關系和齒形曲線的選擇,直到17世紀之后方有理論闡述。
??? 手搖把和踏板機構是曲柄連桿機構的先驅,在各文明古國都有悠久歷史,但是曲柄連桿機構的形式、運動和動力的確切分析和綜合,則是近代機構學的成就。機構學作為一個專門學科,遲至19世紀初才首次列入高等工程學院(巴黎的工藝學院)的課程。通過理論研究,人們方能精確地分析各種機構,包括復雜的空間連桿機構的運動,并進而能按需要綜合出新的機構。
??? 機械工程的工作對象是動態(tài)的機械,它的工作情況會發(fā)生很大的變化。這種變化有時是隨機而不可預見;實際應用的材料也不完全均勻,可能存有各種缺陷;加工精度有一定的偏差,等等。
??? 與以靜態(tài)結構為工作對象的土木工程相比,機械工程中各種問題更難以用理論精確解決。因此,早期的機械工程只運用簡單的理論概念,結合實踐經(jīng)驗進行工作。設計計算多依靠經(jīng)驗公式;為保證安全,都偏于保守,結果制成的機械笨重而龐大,成本高,生產(chǎn)率低,能量消耗很大。
??? 從18世紀起,新理論的不斷誕生,以及數(shù)學方法的發(fā)展,使設計計算的精確度不斷的提高。進入20世紀,出現(xiàn)各種實驗應力分析方法,人們已能用實驗方法測出模型和實物上各部位的應力。
??? 20世紀后半葉,有限元法和電子計算機的廣泛應用,使得對復雜的機械及其零件、構件進行力、力矩、應力等的分析和計算成為可能。對于掌握有充分的實踐或實驗資料的機械或其元件,已經(jīng)可以運用統(tǒng)計技術,按照要求的可靠度,科學地進行機械設計。
機械工程以增加生產(chǎn)、提高勞動生產(chǎn)率、提高生產(chǎn)的經(jīng)濟性為目標來研制和發(fā)展新的機械產(chǎn)品。在未來的時代,新產(chǎn)品的研制將以降低資源消耗,發(fā)展?jié)崈舻脑偕茉矗卫?、減輕以至消除環(huán)境污染作為超經(jīng)濟的目標任務。
??? 機械可以完成人用雙手和雙目,以及雙足、雙耳直接完成和不能直接完成的工作,而且完成得更快、更好。現(xiàn)代機械工程創(chuàng)造出越來越精巧和越來越復雜的機械和機械裝置,使過去的許多幻想成為現(xiàn)實。
??? 人類現(xiàn)在已能上游天空和宇宙,下潛大洋深層,遠窺百億光年,近察細胞和分子。新興的電子計算機硬、軟件科學使人類開始有了加強,并部分代替人腦的科技手段,這就是人工智能。這一新的發(fā)展已經(jīng)顯示出巨大的影響,而在未來年代它還將不斷地創(chuàng)造出人們無法想象的奇跡。
??? 人類智慧的增長并不減少雙手的作用,相反地卻要求手作更多、更精巧、更復雜的工作,從而更促進手的功能。手的實踐反過來又促進人腦的智慧。在人類的整個進化過程中,以及在每個人的成長過程中,腦與手是互相促進和平行進化的。
??? 人工智能與機械工程之間的關系近似于腦與手之間的關系,其區(qū)別僅在于人工智能的硬件還需要利用機械制造出來。過去,各種機械離不開人的操作和控制,其反應速度和操作精度受到進化很慢的人腦和神經(jīng)系統(tǒng)的限制,人工智能將會消除了這個限制。計算機科學與機械工程之間的互相促進,平行前進,將使機械工程在更高的層次上開始新的一輪大發(fā)展。
??? 19世紀時,機械工程的知識總量還很有限,在歐洲的大學院校中它一般還與土木工程綜合為一個學科,被稱為民用工程,19世紀下半葉才逐漸成為一個獨立學科。進入20世紀,隨著機械工程技術的發(fā)展和知識總量的增長,機械工程開始分解,陸續(xù)出現(xiàn)了專業(yè)化的分支學科。這種分解的趨勢在20世紀中期,即在第二次世界大戰(zhàn)結束的前后期間達到了最高峰。
??? 由于機械工程的知識總量已擴大到遠非個人所能全部掌握,一定的專業(yè)化是必不可少的。但是過度的專業(yè)化造成知識過分分割,視野狹窄,不能統(tǒng)觀和統(tǒng)籌稍大規(guī)模的工程的全貌和全局,并且縮小技術交流的范圍,阻礙新技術的出現(xiàn)和技術整體的進步,對外界條件變化的適應能力很差。封閉性專業(yè)的專家們掌握的知識過狹,考慮問題過專,在協(xié)同工作時配合協(xié)調(diào)困難,也不利于繼續(xù)自學提高。因此自20世紀中、后期開始,又出現(xiàn)了綜合的趨勢。人們更多地注意了基礎理論,拓寬專業(yè)領域,合并分化過細的專業(yè)。
??? 綜合-專業(yè)分化-再綜合的反復循環(huán),是知識發(fā)展的合理的和必經(jīng)的過程。不同專業(yè)的專家們各具有精湛的專業(yè)知識,又具有足夠的綜合知識來認識、理解其他學科的問題和工程整體的面貌,才能形成互相協(xié)同工作的有力集體。
綜合與專業(yè)是多層次的。在機械工程內(nèi)部有綜合與專業(yè)的矛盾;在全面的工程技術中也同樣有綜合和專業(yè)問題。在人類的全部知識中,包括社會科學、自然科學和工程技術,也有處于更高一層、更宏觀的綜合與專業(yè)問題。
附錄B
Mechanical engineering course of the development and prospects
Human become "modern" sign is to create tools. The Stone Age stone axes,stone hammers and wood, a simple cortex rough tool is the subsequent emergence of mechanical pioneer. From the manufacture of simple tools created by the evolution of a number of parts, components consisting of modern machinery, has undergone a long process.
Thousands of years ago, mankind has created for the cereals shelling and grinding of the acetabulum and grinding, to provide water and jigging machine Well Water Fetching Tool. equipped with wheels of a car, navigation on the river and paddle boats, organized, such as the rudder. Used the momentum from the man's own physical development of the use of animal power, hydro and wind. From the use of natural materials of stone, wood, soil, leather, the development of man-made materials. The earliest man-made materials are ceramics, pottery manufacture of pottery car, is motivation. Transmission and the integrity of the three parts of machinery.
Mankind from the Stone Age into the Bronze Age and further to the Iron Age. Winds Mong stoves for the blast, the development has played an important role. Powerful enough for the blast, metallurgical furnace can be sufficiently high temperature, can be extracted from ore in the metal. In China, 221 1000-900 years ago has had carriage for the blast. and gradually blast from human to animal and hydraulic blast.
15 ~ 16 centuries ago, the slow development of mechanical engineering. But in the Millennium of practice, the development of machinery or accumulated a lot of experience and technical knowledge, Later in mechanical engineering as an important potential for development. After the 17th century, capitalism in the United Kingdom, France, and the West European countries there, the volume of production has become the central issue.
The late 18th century, the steam engine from the application of the mining industry to promote textile, flour, and metallurgical industries. The main production machinery gradually materials from wood to switch to more resilient, it is difficult to manually processing metals. Machinery manufacturing industry began to take shape, and in several decades as an important industry.
Mechanical engineering through the growing practice, from the scattered, lovingly mainly rely on human ingenuity and craft a song, and gradually developed into a theoretical guidance. system and independent engineering. Mechanical engineering contributed 18 ~ 19th century industrial revolution and the capitalist machinery, large-scale production of the main technical factors.
Dynamics of the development of the important factors of production. The late 17th century, with all the mechanical improvements and development, as the coal and metal ore requirements of the yearly increase, People are relying on the human and animal production can be raised to a new stage.
In Britain, textile mills and other industries will be more and more factories set up by the river, and the use of turbine driven mechanical work. But, at that time, coal, tin and copper mines such as the groundwater, only with a large number of animal resources to upgrade and exclusion. In this production needs, the early 18th century there Newcomen the atmospheric steam engine to drive mine drainage pump. However, the steam engine of this high rate of fuel consumption, basically applies only to coal.
1765, Watt invented the separate condenser of the steam engine, reducing fuel consumption rates. 1781 watts is to create a provider rotary engine of the steam engine, the steam engine to expand the scope of its application. The invention of the steam engine and development, mining and industrial production, railways and shipping have all been of mechanical power. The steam engine to the 19th century is almost the only source of power, but the steam engine and boiler, condenser, cooling water system bulky, bulky and inconvenient to use.
End of the 19th century, the power supply system and electrical began the development and promotion. The early 20th century, the motor industry has replaced the production of the steam engine, all driven into the basic mechanical work force. Mechanized production is inseparable from the electrification and electrification through mechanization only play a role in the production.
Power stations initial impetus for the invention of the steam engine. Early 20th century, emerged as a highly efficient, high speed, high power of the turbine, there to keep the turbine water resources, and promote the power supply system to flourish.
The late 19th century after the invention of the internal combustion engine has improved and become light, small, high efficiency, easy manipulation, could start at any time the original motivation. It was first used to drive without an electricity supply mechanical work on land and later used in vehicles, mobile machinery and ships. to the mid-20th century for railway locomotives. Turbine and the steam engine in the engine exclusion, it has ceased to be an important force driving the machinery. After the invention of the internal combustion engine and gas turbines, jet engines and the development of the aircraft, Spacecraft such as the successful development of the basic technology one of the factors.
Before the industrial revolution, machinery mostly wooden structure, made of wood by hand. Metals (mainly copper, iron) just to manufacture equipment, locks, clocks, pumps and wood structure of small mechanical parts. Metal processing machine Carpenter mainly rely on the intricate communications to the needs of accuracy. The steam engine to power devices in promotion, and the concomitant emergence of mining, metallurgical, ships, locomotives and other large machinery, Forming and processing needs machining metal parts to more, the accuracy requirements are increasingly high. Application of metal materials from copper and iron to the development of the steel-based.
Forging including machining, forging, sheet metal process, welding, heat treatment technology and equipment, and machining technology and machine tools, knife, measuring tools, rapid development, and guarantee the development of the industrial production of machinery and equipment supply.
Socio-economic development of the machinery of the surge in demand for products. Mass production and the increasing precision processing technology progress, a great deal to promote the formation of production methods, such as the production of parts interchangeability, professional division of labor and cooperation, water lines and water processing, and other assembly line.
Simple parts interchangeability and professional collaboration division of production, in ancient times there was already. In mechanical engineering, Interchangeability Mocili reflected in the earliest in 1797 to use its originator of the thread lathe production of bolts and nuts. The same period, the United States engineers Whitney interchangeability with production rifle production methods, shows that the interchangeability of the feasibility and advantages. Such production methods in the United States gradually extended, forming a so-called "American production methods."
Early 20th century, Ford, the car manufacturer has created a pipeline assembly line. Mass production technology combined with Taylor in the late 19th century created the scientific management methods, vehicles and other large-scale production of machinery products will soon achieve production efficiency in the past unimaginable height.
20th century, the late machining the main features are : machine continuously improve the processing speed and accuracy, reduce dependence on manual skills; improve forming, machining and assembly of mechanization and automation; use NC machine tools, machining centers, group technology, the development of flexible manufacturing systems, allowing small and medium-sized manufacturers - multiple types of production to more efficient production of near-mass production level; Study hard and improve processing of a new type of metal and non-metallic materials forming and machining technology.
18 centuries ago, it all depends on the mechanical lovingly experience, intuition and craft mechanical production, with almost no scientific link. To the 18-19th century, the emerging capitalist economy under the promotion, access to scientific knowledge to start production, and the direct production of the Paradise, he started to learn scientific and cultural knowledge, The exchanges between them and the cross-fertilization achieved great results. In this process, and gradually form a set of mechanical engineering on the basis of the theory. .
Dynamic mechanical first and then combining advanced science. The invention of the steam engine were Safuli, Watt, applied physicist Papan and Blake's theory; In the steam engine on the basis of practice, physicist Kano, Portland reserves Kelvin build a new science -- thermodynamics. ICE is the basis of the theory of France Rosa founded in 1862; 1876 Otto application Rosa theory, radically improved his original creation of the true heavy, noise, thermal efficiency and lower engine lay the status of the internal combustion engine. Other steam turbine, gas turbine, the turbine so under the guidance of the theory of the development, Theory and practice also be improved and increased.
As early as 221, China has guidelines on the application of the complex gear systems, Chinese incense burner in the application of the standard to the people of the location of such cross-mechanical switch. Ancient Greece has cylindrical gear and bevel gear and worm drive documented. However, in terms of instantaneous transmission gear ratio and the relationship between tooth and tooth curve of choice, It was not until the 17th century after the side theory expounded.
Knob agencies and pedal crank linkage is the pioneer in the ancient civilization has a long history, But crank linkage in the form of kinetic and dynamic analysis of the precise and comprehensive, is the modern institutions of learning achievements. Mechanism as a specialized disciplines, until the early 19th century was the first to include the Higher Institute (Paris Institute of Technology) courses. Through theoretical study, people can accurately analyze various agencies, including the complex spatial linkages campaign and thus by the need to come up with new institutions.
Mechanical engineering work objects is a dynamic mechanical, its work will change very much. This change is sometimes random and unpredictable; Practical application of the material is not entirely uniform, there may be some shortcomings; Machining accuracy of this deviation, and so on.
And the static structure of the civil engineering work objects, the mechanical engineering problems more difficult to solve theoretical precision. Therefore, the early mechanical engineering only use simple theoretical concepts, practical experience work. Design calculations rely on the empirical formula; To ensure safety, conservative bias, the results were the heavy machinery and large, high cost, low productivity, energy consumption great.
From the 18th century onwards, new birth of the theory of continuous and mathematical methods, the development of the design and calculation precision continuously. The beginning of the 20th century, the emergence of various experimental stress analysis, People can use experimental methods and measuring the physical model on the part of the stress.
20 half-century, the finite element method and the computer's extensive use made of complex machinery and spare parts, components for power, torque, stress analysis and calculation possible. For a full grasp of the practice of experimental data or the machinery or its components, we can use statistical techniques, In accordance with the requirements of the reliability and scientific mechanical design.
Mechanical engineering to increase production, improve labor productivity, raising productivity goals for economic development and to the development of new machinery products. In the next era, new product development will lower their consumption of resources, the development of clean renewable energy, governance, reduce and ultimately eliminate pollution as a super-economic targets and tasks.
Machinery can be completed using hands and eyes, and both feet, his ears and can be completed directly direct the work completed and completed faster, and better. Modern mechanical engineering to create increasingly sophisticated and increasingly complex machinery and mechanical devices, so many previous fantasy become a reality.
Now mankind has been able sky and the upper reaches of the universe, the deep ocean dive, gleaned 10 billion light years distant, nearly monitor cellular and molecular. Emerging electronic computer hardware, software, human sciences began to strengthen, and partially replace the human brain means of science and technology, This is the artificial intelligence. This new development has demonstrated great influence, and in the coming years it will continue to create unimaginable miracle.
Human wisdom is not to reduce the growth of the hands, but instead asked for more hands, more sophisticated and more complicated work, thereby facilitating hand function. Hand practice, in turn, promote the wisdom of the human brain. In the human evolutionary process as a whole, and in each of the process of growing up, brain and hands is a mutual and parallel evolution.
Artificial Intelligence and mechanical engineering akin to the relationship between brain and the relationship between the hands, The only difference lies only in artificial intelligence hardware also need to use the machinery manufactured. The past, various machinery is inseparable from the operation and control its reaction speed and precision operation by the very slow evolution of the human brain and nervous system constraints, Artificial intelligence will eliminate this restriction. Computer science and mechanical engineering among the promotion, parallel, will mechanical engineering at a higher level to start a new round of large-scale development.
19 century, the mechanical engineering knowledge volume is still very limited. European universities which it is also the general and civil engineering as a single subject, known as civil engineering, 19 the second half of the century before becoming an independent discipline. The beginning of the 20th century, along with mechanical engineering technology development and knowledge of the total growth, mechanical engineering begins to decompose, the emergence of specialized branches. This decomposition trend in the mid-20th century, that is before and after the end of the Second World War reached its peak.
As mechanical engineering knowledge has expanded to the total far from the best all in the hands of individuals, some of specialization is essential. However, the excessive specialization of knowledge too divided, and narrow vision, Marketing concept, and not just to co-ordinate large-scale projects for the whole picture and the whole, and to narrow the scope of exchanges of technology, hin
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