機(jī)械制造與自動(dòng)化技術(shù)發(fā)展探究機(jī)械制造與自動(dòng)化畢業(yè)論文

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1、 機(jī)械制造與自動(dòng)化專業(yè) 畢業(yè)論文 論文題目 機(jī)械制造與自動(dòng)化技術(shù)發(fā)展探究 指導(dǎo)老師 學(xué)生姓名 準(zhǔn)考證號(hào) 2017年3月15日 目錄 一、 如何發(fā)展機(jī)械制造自動(dòng)化技術(shù) …………………………… 1 二、注重實(shí)用發(fā)展機(jī)械自動(dòng)化技術(shù) …………………………… 5 三、機(jī)械自動(dòng)化的產(chǎn)生 ………………………………………… 10 四、 機(jī)械自動(dòng)化的現(xiàn)狀 ……………

2、……………………………10 五、 機(jī)械自動(dòng)化的發(fā)展歷程 …………………………………11 六、機(jī)械自動(dòng)化的發(fā)展趨勢 ……………………………………14 機(jī)械制造與自動(dòng)化技術(shù)發(fā)展探究 一、機(jī)械自動(dòng)化技術(shù)的產(chǎn)生及現(xiàn)狀 　 1、機(jī)械自動(dòng)化的產(chǎn)生 機(jī)械自動(dòng)化技術(shù)從上個(gè)世紀(jì)20年代首先在機(jī)械制造冷加工大批量生產(chǎn)過程中開始發(fā)展應(yīng)用，上世紀(jì)60年代后為適應(yīng)市場的需求和變化，為增強(qiáng)機(jī)械制造業(yè)對市場靈活快速反應(yīng)的能力，開始建立可變性自動(dòng)化生產(chǎn)系統(tǒng)，即圍繞計(jì)算機(jī)技術(shù)的柔性自動(dòng)化。它是在制造系統(tǒng)不變或變化較小的情況下，機(jī)器設(shè)備或生產(chǎn)管理過程通過自動(dòng)檢測、信息處

3、理、分析判斷自動(dòng)地實(shí)現(xiàn)預(yù)期的操作或某種過程，并能夠自動(dòng)地從制造一種零件轉(zhuǎn)換到制造另一種不同的零件。社會(huì)實(shí)踐證明，這種定義下的制造系統(tǒng)自動(dòng)化與當(dāng)代大多數(shù)企業(yè)的實(shí)際不相容。目前，世界各國的機(jī)械自動(dòng)化水準(zhǔn)除少數(shù)工業(yè)發(fā)達(dá)國家的某些生產(chǎn)部門外，大多數(shù)還處于操作階段的自動(dòng)化。我國也不例外，需要循序漸進(jìn)，不斷努力，創(chuàng)造條件，向自動(dòng)化的高級(jí)理想階段邁進(jìn)。 2、機(jī)械自動(dòng)化技術(shù)的現(xiàn)狀 　　機(jī)械自動(dòng)化技術(shù)從上個(gè)世紀(jì)20年代開始發(fā)展應(yīng)用以來，已經(jīng)得到了迅速的發(fā)展，特別是近年來計(jì)算機(jī)的高度集成化，開始采用了計(jì)算機(jī)集成制造系統(tǒng)，大大加快了機(jī)械自動(dòng)化的發(fā)展，但我國仍處于初級(jí)操作階段的自動(dòng)化。目前，世界各國的機(jī)械自動(dòng)化水

4、準(zhǔn)除少數(shù)工業(yè)發(fā)達(dá)國家的某些生產(chǎn)部門外，大多數(shù)還處于操作階段的自動(dòng)化。我國也不例外，我國的產(chǎn)業(yè)結(jié)構(gòu)層次低。我國機(jī)械制造業(yè)目前有11.4萬個(gè)企業(yè)，發(fā)展很不平衡，有大量落后于現(xiàn)代水準(zhǔn)的產(chǎn)業(yè)，大部分企業(yè)還比較落后，手工勞動(dòng)占有相當(dāng)?shù)谋戎?，我國能?dú)立開發(fā)現(xiàn)代機(jī)械自動(dòng)化技術(shù)的企業(yè)可以說沒有；我國機(jī)械制造業(yè)企業(yè)中自動(dòng)化裝備少、水準(zhǔn)低，不僅在數(shù)量上同世界先進(jìn)國家有較大差距，而且在品種上、質(zhì)量上、使用上，同世界先進(jìn)水準(zhǔn)也存在階段性差距。實(shí)現(xiàn)我國機(jī)械自動(dòng)化技術(shù)是一個(gè)長期的過程，不可能一蹴而就。需要循序漸進(jìn)，不斷努力，創(chuàng)造條件，向自動(dòng)化的高級(jí)理想階段邁進(jìn)。當(dāng)前，我國還處在社會(huì)主義初級(jí)階段，經(jīng)濟(jì)、財(cái)力、生產(chǎn)力水準(zhǔn)、國

5、民素質(zhì)等，與世界主要國家的差距是很大的；我國有豐富的勞動(dòng)力資源，每年城鎮(zhèn)新增就業(yè)人口達(dá)兩千多萬，且今后每年的就業(yè)人數(shù)還會(huì)增加。機(jī)械自動(dòng)化最大限度地提高勞動(dòng)生產(chǎn)率，勞動(dòng)力的過剩和分工的轉(zhuǎn)移就是一個(gè)現(xiàn)實(shí)問題。 二、機(jī)械自動(dòng)化的發(fā)展歷程 　　機(jī)械自動(dòng)化技術(shù)從本世紀(jì)20年代首先在機(jī)械制造冷加工大批量生產(chǎn)過程中開始發(fā)展應(yīng)用，60年代后為適應(yīng)市場的需求和變化，為增強(qiáng)機(jī)械制造業(yè)對市場靈活快速反應(yīng)的能力，開始建立可變性自動(dòng)化生產(chǎn)系統(tǒng)，即圍繞計(jì)算機(jī)技術(shù)的柔性自動(dòng)化。它是在制造系統(tǒng)不變或變化較小的情況下，機(jī)器設(shè)備或生產(chǎn)管理過程通過自動(dòng)檢測、信息處理、分析判斷自動(dòng)地實(shí)現(xiàn)預(yù)期的操作或某種過程，并能夠自動(dòng)地從制造一

6、種零件轉(zhuǎn)換到制造另一種不同的零件。 70～80年代國際上出現(xiàn)了開始采用計(jì)算機(jī)集成制造系統(tǒng)CIMS(Computer Integrated Manufacturing），柔性自動(dòng)化生產(chǎn)模式也有這種情況。初期犆犐犕犛以信息集成為重點(diǎn)，以較高的自動(dòng)化程度為特征，但在實(shí)現(xiàn)過程中遇到了困難。鑒于實(shí)現(xiàn)計(jì)算機(jī)集成制造系統(tǒng)的全盤自動(dòng)化所需的巨額投入（一個(gè)全盤自動(dòng)化工廠耗資數(shù)百億美元，柔性制造系統(tǒng)一般價(jià)格為600～2500萬美元），所承擔(dān)的巨大風(fēng)險(xiǎn)，加之技術(shù)上的難度與可靠性等問題，世界工業(yè)發(fā)達(dá)國家已開始“碰壁轉(zhuǎn)產(chǎn)”，轉(zhuǎn)而注重信息集成的效果，追求低成本自動(dòng)化LCA(Low Cost Automation

7、）的企業(yè)組織結(jié)構(gòu)和運(yùn)行方式。 　　目前，世界各國的機(jī)械自動(dòng)化水準(zhǔn)除少數(shù)工業(yè)發(fā)達(dá)國家的某些生產(chǎn)部門外，大多數(shù)還處于操作階段的自動(dòng)化。我國也不例外，需要循序漸進(jìn)，不斷努力，創(chuàng)造條件，向自動(dòng)化的高級(jí)理想階段邁進(jìn)。 實(shí)現(xiàn)我國機(jī)械自動(dòng)化技術(shù)是一個(gè)長期的過程，不可能一蹴而就。我國機(jī)械制造業(yè)目前有１１.４萬個(gè)企業(yè)，發(fā)展很不平衡，有大量落后于現(xiàn)代水準(zhǔn)的產(chǎn)業(yè)，大部分企業(yè)還比較落后，手工勞動(dòng)占有相當(dāng)?shù)谋戎?，我國能?dú)立開發(fā)現(xiàn)代機(jī)械自動(dòng)化技術(shù)的企業(yè)可以說沒有；我國機(jī)械制造業(yè)企業(yè)中自動(dòng)化裝備少、水準(zhǔn)低，不僅在數(shù)量上同世界先進(jìn)國家有較大差距，而且在品種上、質(zhì)量上、使用上，同世界先進(jìn)水準(zhǔn)也存在階段性差距。 三、如何發(fā)展

8、機(jī)械制造自動(dòng)化技術(shù) 首先先介紹機(jī)械自動(dòng)化技術(shù)的應(yīng)用與發(fā)展是機(jī)械制造業(yè)技術(shù)改造、技術(shù)進(jìn)步的主要手段和技術(shù)發(fā)展的主要方向。就如何發(fā)展機(jī)械制造自動(dòng)化技術(shù)從四方面進(jìn)行闡述。 機(jī)械自動(dòng)化, 主要指在機(jī)械制造業(yè)中應(yīng)用自動(dòng)化技術(shù), 實(shí)現(xiàn)加工對象的連續(xù)自動(dòng)生產(chǎn),實(shí)現(xiàn)優(yōu)化有效的自動(dòng)生產(chǎn)過程, 加快生產(chǎn)投入物的加工變換和流動(dòng)速度。機(jī)械自動(dòng)化技術(shù)的應(yīng)用與發(fā)展, 是機(jī)械制造業(yè)技術(shù)改造、技術(shù)進(jìn)步的主要手段和技術(shù)發(fā)展的主要方向。機(jī)械自動(dòng)化的技術(shù)水準(zhǔn), 不僅影響整個(gè)機(jī)械制造業(yè)的發(fā)展, 而且對國民經(jīng)濟(jì)各部門的技術(shù)進(jìn)步有很大的直接影響。 　 機(jī)械自動(dòng)化的技術(shù)水準(zhǔn), 不僅影響整個(gè)機(jī)械制造業(yè)的發(fā)展, 而且對國民經(jīng)濟(jì)各部門的

9、技術(shù)進(jìn)步有很大的直接影響。如何發(fā)展我國的機(jī)械自動(dòng)化技術(shù), 應(yīng)實(shí)事求是, 一切從我國的國情出發(fā), 做好各項(xiàng)基礎(chǔ)工作, 走中國的機(jī)械自動(dòng)化技術(shù)發(fā)展之路。 如何發(fā)展我國的機(jī)械自動(dòng)化技術(shù), 應(yīng)實(shí)事求是, 一切從我國的具體國情出發(fā), 做好各項(xiàng)基礎(chǔ)工作, 走中國的機(jī)械自動(dòng)化技術(shù)發(fā)展之路。 　1． 結(jié)合生產(chǎn)實(shí)際, 注重實(shí)用發(fā)展機(jī)械自動(dòng)化技術(shù)。先進(jìn)制造技術(shù)的全部真諦在于應(yīng)用。發(fā)展機(jī)械自動(dòng)化技術(shù), 應(yīng)以企業(yè)的生 產(chǎn)和發(fā)展的實(shí)際需要及具體條件為導(dǎo)向。只有對合適的產(chǎn)品采用與之相適應(yīng)的自動(dòng)化方式進(jìn)行生產(chǎn), 才能收到良好的技術(shù)經(jīng) 濟(jì)效益和社會(huì)經(jīng)濟(jì)效益。我國發(fā)展機(jī)械自動(dòng)化技術(shù), 應(yīng)結(jié)合實(shí)際, 注重實(shí)用, 即對國民經(jīng)

10、濟(jì)產(chǎn)生實(shí)際效益。那種盲目搞自動(dòng)化、 自動(dòng)線的做法, 全年生產(chǎn)任務(wù)只需1~2 個(gè)月就完成的低負(fù)荷 率生產(chǎn)也要搞的傾向應(yīng)當(dāng)糾正, 對國民經(jīng)濟(jì)不產(chǎn)生顯著促進(jìn)、效率低下的要緩搞。我們要的是效益, 而不單純的是速度。 　2． 發(fā)展投資少、見效快的低成本自動(dòng)化技術(shù)。發(fā)展低成本自動(dòng)化技術(shù), 潛力大, 前景廣, 投資省, 見效快, 提高自動(dòng)化程度, 可以收到事半功倍的經(jīng)濟(jì)效果, 適合我國現(xiàn)階段的發(fā)展需要和國情。20 世紀(jì)90 年代美國麻省理工學(xué)院提出的精節(jié)生產(chǎn)LP ( Lean Production) 模式, 就是以最小的投入, 取得最大的產(chǎn)出的具體表現(xiàn)。借鑒國外發(fā)展機(jī)械制造業(yè)低成本自動(dòng)化技術(shù)的經(jīng)驗(yàn)是有益

11、的。我國機(jī)械制造業(yè)各企業(yè)有大量的通用設(shè)備, 在發(fā)展現(xiàn)代機(jī)械自動(dòng)化技術(shù)時(shí), 應(yīng)以原有的設(shè)備為主, 合理調(diào)整機(jī)床布局, 添加少量的數(shù)控設(shè)備, 引入CAD/CAM技術(shù), 充分發(fā)揮計(jì)算機(jī)自動(dòng)化管理的優(yōu)勢和人的創(chuàng)造性, 共同構(gòu)成一個(gè)以人為中心, 以信息自動(dòng)化為先導(dǎo)、樹立自主的單元化生產(chǎn)系統(tǒng), 為我國機(jī)械制造業(yè)自動(dòng)化技術(shù)發(fā)展應(yīng)用提供了一條投資少、見效快、效益高、符合我國國情的機(jī)械自動(dòng)化技術(shù)發(fā)展應(yīng)用新途徑。通用機(jī)的局部自動(dòng)化改裝有重要意義。近期內(nèi)我國對成本低、維修方便的通用機(jī)的需要量還是不會(huì)急劇下降的, 因?yàn)橛袕V大的鄉(xiāng)鎮(zhèn)企業(yè)市場, 有小工廠、試驗(yàn)室、大型企業(yè)的工具車間等。 　　 3． 結(jié)合中國國情, 發(fā)展

12、現(xiàn)代機(jī)械自動(dòng)化技術(shù)。實(shí)現(xiàn)機(jī)械自動(dòng)化是一個(gè)由低級(jí)到高級(jí)、由簡單到復(fù)雜、由不完善到完善的發(fā)展過程。當(dāng)機(jī)械的操作采用自動(dòng)控制器后, 生產(chǎn)方式才從機(jī)械化逐 步過渡到機(jī)械控制( 傳統(tǒng)) 自動(dòng)化、數(shù)字控制自動(dòng)化、計(jì)算機(jī)控制自動(dòng)化。只有建立了自動(dòng)化工廠后, 生產(chǎn)過程才能全盤自動(dòng)化,才能使生產(chǎn)率全面提高, 達(dá)到自動(dòng)化的高級(jí)理想階段。 中國實(shí)現(xiàn)機(jī)械自動(dòng)化技術(shù)應(yīng)是一個(gè)長期的過程, 不可能一蹴而就。當(dāng)前, 中國機(jī)械制造業(yè)同世界先進(jìn)水準(zhǔn)也存在階段性差 距。在我國這種國情下, 普遍發(fā)展應(yīng)用計(jì)算機(jī)集成制造系統(tǒng)的“全盤自動(dòng)化”或“高度自動(dòng)化”, 并不具備必要的基礎(chǔ)技術(shù)、經(jīng)驗(yàn)和投資能力。因此, 要不要普遍發(fā)展全盤自動(dòng)化或高度

13、自動(dòng)化CIMS 技術(shù), 一定要慎重行事。而且全盤自動(dòng)化或高度自動(dòng)化的CIMS 技術(shù)也并非我國機(jī)械制造業(yè)的當(dāng)務(wù)之急, 只能列為機(jī)械制造自動(dòng)化技術(shù)的主要發(fā)展方向。應(yīng)該發(fā)展工藝成熟的大批量生產(chǎn)的自動(dòng)化技術(shù)。我國現(xiàn)階段, 在產(chǎn)品數(shù)量較大的同類產(chǎn)品連續(xù)流水作業(yè)的切削加工生產(chǎn)中, 自動(dòng)化設(shè)備仍然是半自動(dòng)機(jī)床、自動(dòng)機(jī)床、組合機(jī)床及其組成的自動(dòng)線、回轉(zhuǎn)體零件加工自動(dòng)線等。而在大批量的鑄造、鍛造、沖壓、焊接、熱處理和裝配等生產(chǎn)中, 采用剛性自動(dòng)化( 自動(dòng)單機(jī)和自動(dòng)線) 則是合理可行的, 能取得較好的經(jīng)濟(jì)效益; 對于品種稍多的成批生產(chǎn), 應(yīng)采用由快速重新調(diào)整的設(shè)備組成成組工段或流水線、可更換主軸箱組合機(jī)床自動(dòng)線、

14、短自動(dòng)線和復(fù)合制造單元, 實(shí)現(xiàn)成組自動(dòng)化; 而單件小批量生產(chǎn), 應(yīng)從推廣成組技術(shù)入手, 適當(dāng)發(fā)展采用數(shù)控機(jī)應(yīng)酬或加工中心, 有針對性地建立一些揉性制造單元FMC( Flexible Manu- facturing Cell) , 可取 得較好的經(jīng)濟(jì)效果。 我國作為一個(gè)發(fā)展中國家, 考慮一切生產(chǎn)技術(shù)問題時(shí)的前提必須是適用。我國消化吸收國外柔性制造系統(tǒng)( Pseudo- FMS) , 是要確保必要的生產(chǎn)柔性的前提下, 優(yōu)化人機(jī)界面, 不過分追求 自動(dòng)化, 盡可能建立較為完善的信息系統(tǒng), 充分發(fā)展計(jì)算機(jī)管理的效益。系統(tǒng)中先進(jìn)的自動(dòng)化裝備和普通設(shè)備并存, 系統(tǒng)的某些環(huán)節(jié)允許人工干預(yù)。這是一個(gè)典型的結(jié)

15、合國情、實(shí)施適用先進(jìn)方針的自動(dòng)化技術(shù)解決方案。我國目前在消化呼吸、融會(huì)貫通國際上有用的自動(dòng)化技術(shù)理論的基礎(chǔ)上, 要努力做到從我國機(jī)械制造業(yè)的實(shí)際情況出發(fā), 發(fā)展創(chuàng)新, 形成有國情特征的發(fā)展自動(dòng)化技術(shù)理論和學(xué)說, 進(jìn)行圍繞計(jì)算機(jī)技術(shù)的柔性自動(dòng)化技術(shù)的開發(fā)研究, 以適用為前提, 急需什么就解決什么, 取得實(shí)踐經(jīng)驗(yàn)再 推廣應(yīng)用。 　 4． 抓好基礎(chǔ), 注重配套發(fā)展機(jī)械自動(dòng)化技術(shù)。發(fā)展應(yīng)用機(jī)械自動(dòng)化技術(shù), 要扎扎實(shí)實(shí)地抓好自動(dòng)化技術(shù)應(yīng)用項(xiàng)目的基礎(chǔ)工作和從實(shí)際出發(fā)的推廣應(yīng)用工作, 既要發(fā)展主機(jī), 也要配套發(fā)展自動(dòng)化元件及控制系統(tǒng)?？删幊炭刂破?、微處理機(jī)、各種傳感器、新型刀具、控制系統(tǒng)及系統(tǒng)軟件、電子計(jì)

16、算機(jī)等將是今后機(jī)械自動(dòng)化的主要技術(shù)基礎(chǔ)。研究生產(chǎn)大量性能優(yōu)良、自動(dòng)化水準(zhǔn)高的機(jī)電產(chǎn)品是發(fā)展應(yīng)用機(jī)械自動(dòng)化技術(shù)的關(guān)鍵。自動(dòng)化生產(chǎn)時(shí), 在系統(tǒng)的結(jié)構(gòu)、質(zhì)量( 重量) 、體積、剛性和耐性等方面對現(xiàn)代機(jī)械自 動(dòng)化技術(shù)有著重要的影響, 機(jī)械技術(shù)應(yīng)利用其它高新技術(shù)來更新, 實(shí)現(xiàn)與適應(yīng)現(xiàn)代機(jī)械自動(dòng)化技術(shù)的發(fā)展; 自動(dòng)化生產(chǎn)時(shí), 機(jī)械制造系統(tǒng)的自動(dòng)控制、自動(dòng)檢測、伺服系統(tǒng)的操作等都少不了要應(yīng)用微電子技術(shù)和自動(dòng)控制理論; 自動(dòng)化生產(chǎn)時(shí), 信息的交換與處理、存取、運(yùn)算、判斷和決策等都少不了要應(yīng)用計(jì)算機(jī)與信 息處理技術(shù)。 　 總之, 我國機(jī)械制造業(yè)發(fā)展應(yīng)用自動(dòng)化技術(shù), 不但要起點(diǎn)高, 瞄準(zhǔn)世界先進(jìn)水準(zhǔn), 而且必須

17、包括各種靈活的低成本、見效快的自動(dòng)化技術(shù), 堅(jiān)持提高與普及相結(jié)合的方針, 我國的機(jī)械自動(dòng)化技術(shù)發(fā)展應(yīng)用才能健康地走上高速度、高質(zhì)量和高效益之路 。 四、機(jī)械自動(dòng)化的發(fā)展趨勢 隨著現(xiàn)代科學(xué)技術(shù)的進(jìn)步和現(xiàn)代高效農(nóng)業(yè)的不斷發(fā)展，自動(dòng)化控制技術(shù)在農(nóng)業(yè)現(xiàn)代過程中不可替代的地位和作用越來越被人們所認(rèn)識(shí)。農(nóng)業(yè)自動(dòng)化能夠大大提高勞動(dòng)生產(chǎn)率和增加勞動(dòng)舒適性，而且隨著經(jīng)濟(jì)的全球化，面臨農(nóng)產(chǎn)品開放進(jìn)口和市場競爭的壓力，現(xiàn)代業(yè)只有通過進(jìn)一步提高生產(chǎn)率、降低生產(chǎn)成本和提高產(chǎn)品品質(zhì)才能生存。從這些新的需求出發(fā)，農(nóng)業(yè)生產(chǎn)著高效率和高精度的機(jī)械化、自動(dòng)化方向發(fā)展是必然的選擇。 　　日前農(nóng)業(yè)機(jī)械自動(dòng)化大致有以下3類。一是

18、已有農(nóng)業(yè)機(jī)械及裝置的部分自動(dòng)化控制。這種自動(dòng)化方式以提高已有農(nóng)業(yè)機(jī)械及裝置的作業(yè)與操作性能，提高作業(yè)效率和作業(yè)精度，減輕駕駛員的負(fù)擔(dān)，節(jié)約資源等為目的。二是已有農(nóng)業(yè)機(jī)械及裝置的無人自動(dòng)操作。這種自動(dòng)化方式用在操作簡單且容易實(shí)現(xiàn)無人運(yùn)轉(zhuǎn)，危險(xiǎn)性大或是長時(shí)間重復(fù)單調(diào)過程的作業(yè)上。如用計(jì)算機(jī)程序或無線電遙控來操縱拖拉機(jī)及聯(lián)合收割機(jī)、自動(dòng)控制行駛、自動(dòng)檢測耕深、耕寬或作物行列數(shù)、自動(dòng)完成作業(yè)，以及能使下煤機(jī)、自動(dòng)化溫室等固定裝置自動(dòng)完成作業(yè)的機(jī)械及裝置。三是農(nóng)業(yè)機(jī)器人。農(nóng)業(yè)機(jī)器人是一種可由不同程序軟件控制，以適應(yīng)各種作業(yè)，能感覺并適應(yīng)作物種類或環(huán)境變化，有檢測(如視覺等)和演算等人工智能的新一代無人自

19、動(dòng)操作機(jī)械。 　　自動(dòng)化技術(shù)特別是微電子自動(dòng)控制技術(shù)在農(nóng)機(jī)上的成功應(yīng)用，是農(nóng)業(yè)現(xiàn)代化的重要標(biāo)志之一。根據(jù)我國實(shí)際國情，必須考慮該技術(shù)的成熟程度，即自動(dòng)化技術(shù)本身的可靠性，必須考慮整機(jī)售價(jià)應(yīng)適臺(tái)我國農(nóng)民當(dāng)前的購買力，以及采用自動(dòng)化技術(shù)的實(shí)用性和農(nóng)民在操作使用維修保養(yǎng)時(shí)的方便性。 　　現(xiàn)在農(nóng)業(yè)生產(chǎn)自動(dòng)化控制系統(tǒng)基本上是各種系統(tǒng)的集成，硬件上有傳感器、傳感器變換器接口、控制器、計(jì)算機(jī)網(wǎng)絡(luò)、被控設(shè)備、總線等組成的。隨著自動(dòng)化信息技術(shù)和生物技術(shù)以及工程制造業(yè)的發(fā)展，智能控制技術(shù)的廣泛應(yīng)用，農(nóng)業(yè)生產(chǎn)的精確控制必然是現(xiàn)代農(nóng)業(yè)生產(chǎn)的發(fā)展方向。 參考文獻(xiàn) 1. 翁貽方，趙長德.現(xiàn)代控制技術(shù)基礎(chǔ).機(jī)械工業(yè)

20、出版社，2003.4 2. 馮辛安.機(jī)械制造裝備設(shè)計(jì).第二版.機(jī)械工業(yè)出版社，2009.1 3. 龍飛.autoCAD2007機(jī)械圖形設(shè)計(jì).電子科技大學(xué)出版社，2007.1 4. 應(yīng)錦春.現(xiàn)代設(shè)計(jì)方法.機(jī)械工業(yè)出版社，2000.4 5. 全燕鳴.機(jī)械制造自動(dòng)化.華南理工大學(xué)出版社, 2008.6 6. 周驥平，林崗.機(jī)械制造自動(dòng)化技術(shù).機(jī)械工業(yè)出版社，2005.3 An Analysis of Characteristics of American Slang Abstract: With the development of the societ

21、y, slang is widely used by more and more people, especially in America, slang can be found favorable in the Americans’ eyes. Slang has gradually become popular among English speakers, since it appeared in English language in the 16th century. It is very popular in the English-speaking countries nowa

22、days. Rich and colorful slang is an important component in English. However, it is difficult for people to understand. Therefore, it is necessary for us to study it. To have a glimpse into the nature of English slang is helpful to understand. This thesis expounds the characteristics of English slang

23、. It concludes that slang is playing a more and more important role in the society of English-speaking. Key words: slang characteristics American Introduction Slang is a rather special parole. It is neither the word that beyond the regular role of grammatical usage, nor rural dialect.

24、Although it is quite different from acrolect which used on the formal occasion, people quite like to use it in daily speech. That is to say, slang can be defined to common colloquial language, and slang is usually used as colloquial words and phrase. In other words, slang is Nonstandard-English. It

25、is brimming with youth vigor. It is rather a spoken language than a written one. Unlike standard language, it does not from its own grammar rules. Mainly employed by sub-cultural groups, slang is highly colloquial, informal and essentially not respectable. Most of slang is more forceful, emotional o

26、r humorous forms than standard words. Slang is very informal and commonly used in speech. Between people from same social group or who work together, not considered suitable for formal contexts and often not in used for long. Slang has become an indispensable part of modern English. With the popular

27、ity of slang, we should know how to use slang and master its characteristics. This paper intends to make a tentative study on the characteristics of slang in America. 1. Highly Colloquial Slang is highly colloquial, non-standard informal language. Being the quintessence of colloquial speech, slang

28、 is always related to convenience rather than to scientific laws, grammatical rules and philosophical ideas. It does not belong to the register of language used in formal records, epics, poetry, religious prose and other varieties of literature. As it originates from colloquial speech, so it flouris

29、hes best in colloquial speech. Slang, as a whole, is mainly employed in everyday, oral communications between friends and acquaintances or just within some special groups. On informal, private occasions, slang is the favorite means for oral communication. On some friendly occasion, when you talk in

30、 very formal way, maybe it will give others a feeling that you are talking with them in a commanding tone. Such feeling will broaden the distance between you and your friend. However, when you add some proper slang in your talking, you can have the talking atmosphere more friendlily. For example, a

31、 person wants to get his friend’s agreement eagerly. If the friend can understand the speakers’ feeling and his eagerness, he may say the following sentences: “I will drink that sentence.” It means “I definitely agree with you.” or “I will to accept advice.” Not only can the friend have his companio

32、n relaxed, but also express his agreeable attitude. 2. Transience of slang’s life Slang is generally transient. Generally speaking, slang spreads very quickly yet it is unstable and temporary. That is to say, slang is the most unstable element of English and its life expectancy is generally sho

33、rt. Usually a popular slang of last year may no longer be heard this year or some slang once used by one generation may sound Greek to the next. The use of slang is closely related to the circumstances in which it is used. Once the circumstances changed, the slang relevant to it disappears too. Howe

34、ver, not all the slang words die soon after its birth. Some linger on decade after decade, century after century, never becoming respectable or dying out. Take the word “booze” for example; it was used as slang in the Middle Ages, yet now it is still ranked among slang in some dictionaries. The word

35、 “dough” , a slang word for money, is just as hardly possible to become a standard word as it ever was, though no more respectable. Many old words have been cut off and a large amount of new words are added to slang. People’s attitudes toward slang vary from person to person. Some think that slang c

36、annot be used on the formal occasion, for the illiterate people speak it only and the slang terms are so coarse. However, others hold the opposite idea. They think that slang play an important role in English language, because of its fresh, lifelike, humor and adequate expressions. 3. Abundance of

37、Synonyms Slang is abundant of synonyms. By the phrase “abundant of synonyms”, it refers to two phenomena. One is that slang almost exists side by side with another more general term for the same thing. For example, the slang phrase “as luck would have it” has been used by some speakers in the meani

38、ng “fortunately”. The difference between “as luck would have it” and “fortunately” can be stated only in reference to the people who use the word. Some say “As luck would have it, I found exactly what I was looking for”, others “Fortunately, I found exactly what I was looking for”, “As luck would ha

39、ve it “is slang and “fortunately” is not. Because “As luck would have it” is used by limited part of population, whereas, “fortunately” is used by everyone. It is found that slang can be regarded as words and phrases or particular meanings of words in common informal use, but generally it is not see

40、n as standard in a language that used by specified expression or class. It is natural to refer it as the words that are commonly used, and can be understood by all people in America. 4. Visualization of language You can express the same meaning with the standard language as well as slang. Neverthe

41、less, slang maybe used to make your language more picturesque. It reveals something about the feeling or attitudes of the speaker. For example, a boss was very angry with his workers because they were dilatory in doing things. To emphasize his anger, he says, “Two hours off with the pay, why the hel

42、l are they dragging their tails. The slang “drag one’s tail” means, “Do something too slowly”. The speaker’s angry is displayed. Take another case for example “Thomas, a sad apple. Can he finish such special task?” In his sentence, “sad apple” means “a person who is always discouraged” The speaker e

43、xpresses his deep suspicion with the aid of slang better than in the formal way. In a word, colloquialism is one of the characteristics of slang .It is spoken rather than written. Although more and more writers make use of American slang of contemporary teenagers, no matter how many slang words one

44、 can find in the novel, they are all used in the dialogues or conversation of its characters instead of in the narration or description. Therefore, they are still “spoken” though in writing. Conclusion In the recent years, slang has been changing with each passing day and with the world’s develo

45、pment. Many old words have disappeared and lots of new words are added to slang. In a word, since slang’s appearance, it has been gaining respectfulness and plays important role in the social status. In the social life, even the words “hi” and “bye-bye” are slang words. Therefore, it is wrong if som

46、eone neglect slang’s study and slang translation. Slang has its special means and principles. Although slang is popular now, the people should selectively use it. If it is not special situation and has no context, we must not use it randomly. Slang can express different meaning and different informa

47、tion, but what it can perform actually depend on the language background. If we do not consider the occasion of talking, but only want to choose some slang to show out language character, maybe our talking will be thought as uncivil and improper. Bibliography De Klerk, V. Hall. New Dictionary o

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