ZG型振動給料機設計【含CAD圖紙、說明書】
畢業(yè)設計(論文)任務書 機電工程 學院 機械設計制造及自動化 專業(yè)設計(論文)題目 ZG型振動給料機設計 學 生 姓 名 班 級 起 止 日 期 指 導 教 師 教研室主任 發(fā)任務書日期 1.畢業(yè)設計的背景: 目前,振動機械的利用已經(jīng)成為機械行業(yè)的一個有廣泛發(fā)展前途的、并與生產(chǎn)有著密切關系的重要分支。據(jù)統(tǒng)計,現(xiàn)用于工業(yè)中的振動機械有上百之多,其中有振動給料機、振動輸送機、振動篩和共振篩,作為通用機械,已被廣泛用于采礦、冶金、化工、輕工、機械、電力、建筑、建材、交通、水利、鐵道和國防等工業(yè)部門。因此,我們需要不斷的推陳出新,讓現(xiàn)代化的生活更加便捷。2.畢業(yè)設計(論文)的內(nèi)容和要求: 內(nèi)容:1給料機的振動給料的基本原理 2系統(tǒng)的運動過程 3總體結構及重要零部件的設計要求:結構簡單、緊湊堅固,操作方便,外型美觀。3.主要參考文獻: 1振動篩 振動給料機 振動輸送機的設計與調(diào)試2機械設計手冊3慣性振動給料機的研究與優(yōu)化設計4ZG型慣性振動給料機的動力學研究5機械設計工程學4.畢業(yè)設計(論文)進度計劃(以周為單位):起 止 日 期工 作 內(nèi) 容備 注第1、 2周第3、4周第5、6周第7、8周第9、10周第11、12周第13、14周第15、16周確定選題,查閱相關資料,對設計的題目給料機有了一個初步的認識。根據(jù)手冊等一系列參考文獻,來確定給料機需要設計部分的參數(shù),并進行相關計算。繼續(xù)前兩周未完成的工作,對計算部分校驗。根據(jù)計算數(shù)據(jù)和一些資料,開始進行繪總裝圖的草圖。在導師的指導改正下,修正圖,并用CAD繪制。繪制各部分零件圖,并編寫說明書。對整個設計進行修正。準備答辯。教研室審查意見: 室主任 年 月 日學院審查意見: 教學院長 年 月 日 畢業(yè)設計(論文)開題報告課 題 名 稱: ZG型振動給料機設計 學 生 姓 名:指 導 教 師:所 在 學 院:專 業(yè) 名 稱: 說 明1根據(jù)徐州工程學院畢業(yè)設計(論文)管理規(guī)定,學生必須撰寫畢業(yè)設計(論文)開題報告,由指導教師簽署意見、教研室審查,學院教學院長批準后實施。2開題報告是畢業(yè)設計(論文)答辯委員會對學生答辯資格審查的依據(jù)材料之一。學生應當在畢業(yè)設計(論文)工作前期內(nèi)完成,開題報告不合格者不得參加答辯。3畢業(yè)設計開題報告各項內(nèi)容要實事求是,逐條認真填寫。其中的文字表達要明確、嚴謹,語言通順,外來語要同時用原文和中文表達。第一次出現(xiàn)縮寫詞,須注出全稱。4本報告中,由學生本人撰寫的對課題和研究工作的分析及描述,沒有經(jīng)過整理歸納,缺乏個人見解僅僅從網(wǎng)上下載材料拼湊而成的開題報告按不合格論。5. 課題類型填:工程設計類;理論研究類;應用(實驗)研究類;軟件設計類;其它。6、課題來源填:教師科研;社會生產(chǎn)實踐;教學;其它課題名稱ZG型振動給料機課題來源生產(chǎn)實踐課題課題類型工程設計類選題的背景及意義目前,振動機械的利用已經(jīng)成為機械行業(yè)的一個有廣泛發(fā)展前途的、并與生產(chǎn)有著密切聯(lián)系的重要分支。據(jù)統(tǒng)計,現(xiàn)用于工業(yè)中的振動機器有上百種之多,其中振動給料機、振動輸送機、振動篩和共振篩,作為通用機械,已被廣泛用于采礦、冶金、煤炭、化工、輕工、機械、電力、建筑、建材、交通、水利、鐵道和國防等工業(yè)部門。因此,我們需要不斷的推陳出新,讓現(xiàn)代化的生活更加方便,簡捷。研究內(nèi)容擬解決的主要問題1 給料機振動給料的基本工作原理2 給料機系統(tǒng)的運動分析3 設備總體設計和關鍵零部件的結構設計研究方法技術路線 首先查閱資料,了解了振動給料機的工作原理,它的作用是拋起槽體中的物料,并按拋物線軌跡向前跳躍,以達到給料的目的。用于礦山冶金、機械等行業(yè)對物料的中間轉載式勻速給料領域。弄清楚它的作業(yè)流程之后,再計算研究所需的參數(shù),決定各裝配部分。研究的總體安排和進度計劃第1、2周 畢業(yè)實習第3、4周 查閱資料,詳細了解振動給料機第5、6周 進行參數(shù)計算第7、8周 繪制總裝圖的草圖第9、10周 繪制總裝圖的CAD圖第11、12周 繪制各部件圖和零件圖第13、14周 檢查所有圖紙的錯誤,并編寫說明書第15、16周 準備答辯主要參考文獻1 振動篩 振動給料機 振動輸送機的設計與調(diào)試2 ZG慣性振動給料機的動力學研究3 慣性振動給料機的研究與設計優(yōu)化4 電磁振動給料機的力學模型5 機械設計手冊6 機械工程學手冊7 變頻器的基礎及應用指導教師意 見 指導教師簽名: 年 月 日 教研室意見學院意見教研室主任簽名:年 月 日 教學院長簽名: 年 月 日壓縮包內(nèi)含有CAD圖紙和說明書,咨詢Q 197216396 或 11970985圖書分類號:密 級:57摘要振動機械廣泛應用于各類工業(yè)部門中,特別是礦山工業(yè)中,物料的給料、輸送、篩分、脫水、脫介和破碎、磨碎等作業(yè),都可使用振動機械。振動給料機在生產(chǎn)流程中,可把塊狀、顆粒狀物料從貯料倉中均勻、連續(xù)地給到受料設備中去。適用于自動配料,定量包裝和自動控制.它主要由兩大部分組成:槽體和激振器.本設計中,激振器采用的是雙電機式激振器,以電機作為激振源,提供振動所需的激振力. 這就保證了噪聲低,耗電小,調(diào)節(jié)性能好,無沖料現(xiàn)象.為防止振動力過大,破壞地基,需要用橡膠彈簧作為減振系統(tǒng).通過選擇合適的變頻器來使給料機的固有頻率與激振頻率靠近,以實現(xiàn)雙質體共振.本設計整體實現(xiàn)了給料機的結構簡單,運行可靠,調(diào)節(jié)安裝方便,重量輕,體積小等特點. 振動給料機的發(fā)展和提高在礦山采掘和生產(chǎn)加工工業(yè)發(fā)展中占有很重要的地位,新技術新產(chǎn)品的開發(fā)和應用,是一項非常重要的任務.關鍵詞 振動給料機; 設計 AbstractVibration machinery has been widely used in various industrial sectors, especially in the mining industry, materials feeding, transmission, screening, dehydration and broken, grinding and other operations, they all can use the vibration machine. Mechanical vibration feeder can give massive, granular material from the storage silos in uniform into the material equipment in the production process. It applies to the automatic ingredients, packaging and quantitative control. It is mainly composed of two major parts: Slot and Vibrator . The design of the exciter is a double-vibration motor and the electrical excitation as a source of vibration provides the necessary exciting force. This ensures low noise, small power consumption, perfect condition and no-expected phenomenon. In order to prevent excessive vibration from destructing the foundation, it needs using rubber as a spring damping system. By selecting the appropriate frequency converter to make the feeder similar to the natural frequency of vibration frequencies .It can achieves the quality of dual-resonance. The simple overall structure, reliable operation, regulation of easy installation, light weight, small size and other characteristics can achieve. The enhance and development in the mining and manufacturing industrial development play important roles ,the development and applications of new products and new technology are very important tasks.Key words Mechanical Vibration Feeder Design 目 錄1 緒論11.1我國振動給料設備的發(fā)展沿革12 給料機的工作原理43 承載構件的結構設計63.1承載構件的型式63.2承載構件的剛度63.3槽體主要尺寸的確定73.4振動篩板的結構設計84 工藝參數(shù)的選擇104.1 給料機的長度及寬度104.2 振幅和頻率104.3 振動電機激振力計算114.4 物料的平均速度124.5 給料機生產(chǎn)能力124.6 應用及改進125 振動分析145.1 振動電機的振動給料機動力學分析145.2 力學模型分析155.3 考慮存在阻尼時的振動的分析175.4 固有頻率與激振頻率196 振動給料機電機功率的計算206.1振動給料機及振動篩啟動過程分析206.2電機功率的計算227 強度校核237.1 焊接校核237.1.1 焊接介紹237.1.2 焊接的質量檢查237.1.3 靜載荷作用下焊接的計算237.1.4 交變載荷作用下的強度計算247.2 橡膠彈簧257.2.1 橡膠彈簧特性258 變頻器的調(diào)速方式及合理選擇268. 1 引言268.2 變頻調(diào)速方式的確定268.3 控制方式的選擇288.4 變頻器的分類298.5 變頻器的選擇298.5.1選擇變頻器品牌型號298.5.2選擇變頻器規(guī)格298.5.3 選擇的變頻器應滿足的條件308.6 變頻調(diào)速原理308.6.1 變頻器的基本結構308.6.2變頻器的控制電路308.6.3 變頻調(diào)速的基本原理318.6.4 變頻調(diào)速的優(yōu)點339 系統(tǒng)的設計實現(xiàn)349.1 可編程控制器概述349.1.1 PLC簡介349.2 主要特點369.3 PLC系統(tǒng)結構379.4 系統(tǒng)硬件實現(xiàn)379.4.1 容量選擇及定方法振幅379.4.2變頻器控制電氣原理38結論41致謝42參考文獻43附錄44 1 緒論1.1 我國振動給料設備的發(fā)展沿革20世紀50年代初,礦井用給料設備主要依賴機械式往復給料機。該機型結構簡單,動力消耗較大,設備笨重。其原理是:由連桿及偏心軸傳動,往復作業(yè),處理量小,成間接堆式不均勻給料。但該機型維修量小、耐用,布置所需高度低,對物料的粒度組成、外在水分等物理性質要求不嚴。已廣泛用在各類礦井生產(chǎn)中。特別是煤礦井下,直到目前,對其在惡劣條件下的適用性仍給予好評。隨著礦井機械化程度的提高,對K型往復式給料機已作了大量改進,由單屈臂改為雙屈臂,給料量已增加到1 000- 2 000 t / h 。60年代,隨著生產(chǎn)技術的發(fā)展,相繼出現(xiàn)了電磁振動給料機,并迅速得到廣泛應用。原機械工業(yè)部相繼在東北的遼陽、河南鶴壁和江蘇海安設立3家定點生產(chǎn)廠。該機型屬于雙質體共振鋼型彈力振動,相對于K型往復給料機,其適應性更加廣泛。由于結構緊湊、質量輕、可無級調(diào)速以及適用220 - 380v不同等級電壓與電耗少等特點,從而得到了推廣。然而,由于該機型存在電磁鐵振動時噪聲大、振頻高(3 000次/min)、振幅小( 1- 1.5mm)和調(diào)整運量的振幅大小取決于E型電磁鐵靜塊與動塊間隙、板彈簧片數(shù)以及聯(lián)接桿螺母松緊程度等原因,如果調(diào)節(jié)不當,間隙太大則電流增大(長時間線圈鐵芯會發(fā)熱損壞),間隙過小造成振幅減少,致使用戶深感生產(chǎn)管理不便。特別是在增加調(diào)速時,因噪聲過大影響職工身心健康。為減少料倉直接作用在給料機上物料的垂直壓力,配置料斗及導料倉時要有一定的角度和高度;對水分大、結濕滯性物料,因其頻率高、振幅小出現(xiàn)板結和不下料現(xiàn)象,使其局限于非防爆場合使用;因電磁鐵怕水、怕潮、振動時會產(chǎn)生火花而導致瓦斯爆炸,對密度較大礦石的給料也不太適合;因振幅小對物料拋浮力小,其給料量也受到限制。 到了70年代末至80年代初,一種單質體以振動電機加偏心塊離心力為振源的給料設備應運而生。該機型簡單明快,自動調(diào)節(jié)同步運動,選用4- 6極電機、轉數(shù)為960-1 450轉/min,振幅可達4 - 12 mm。但使用中發(fā)現(xiàn),該機型有先天缺陷:振源為特殊電機。在偏心塊作用下,對電機軸承的質量,密封程度要求過高,且成功保質功率為2. 2kW。如需防爆,不但造價高,對其性能,亦非一般生產(chǎn)廠家能保證,而且價格昂貴;參振電機在振動槽上采用直接連接方式安裝,軸承除承受正常徑向力外,尚有較大的軸向力,嚴重影響電機壽命。在使用率較高的地方,常因軸承游隙過大或缺油造成電機掃膛而燒壞,使生產(chǎn)無法正常進行,頻繁更換會給用戶帶來經(jīng)濟損失;電機直接參振的槽體,其兩臺電機開機需強制同步,會因振動使槽體破裂。在槽體載料過重或出現(xiàn)卡死情況下,電機強行啟動易造成過流燒壞,剪斷固定電機螺栓,使電機掉下傷人。這些先天缺陷使強制同步型給料設備的應用受到很大限制。后來,雖然國內(nèi)生產(chǎn)廠對電機質量不斷改善,但無法改變該機型先天性的技術缺陷。 在80年代末90年代初,針對強制同步振動電機為振源的給料設備的使用狀況,研制開發(fā)了一種電機不參振型新型給料設備。GZ型是參照波蘭設備研制的單質體振動給料機。該機以普通電機為振源,繞性連接槽體下方的激振器。激振器內(nèi)有兩根可調(diào)偏心軸。通過電機繞性傳動,一對齒輪轉動產(chǎn)生激振力。它的出現(xiàn)是強制式電機振動給料設備的更新?lián)Q代產(chǎn)品,給料均勻、運行可靠、對物料的水分及粒度適用性強。該機采用前吊后座配置,以不燒電機著稱。該機存在的問題是:現(xiàn)場配置需固定電機底架,占用一定空間;繞形連接因槽體載重過量卡死后,強行啟動會撕裂;動態(tài)與靜態(tài)配連安裝時要求上下左右留有一定的活動量,而且因無減振系統(tǒng),激振力直接傳遞給機身的地基,其沖擊力及噪聲較大;激振器重力軸以及齒輪材質要求高;要求激振箱注油降溫,密封不嚴會漏油,造成二次污染,缺油后齒輪發(fā)熱起火,存在不安全隱患。目前,該機型已發(fā)展成系列產(chǎn)品-GZY,GZM,GZK,在國內(nèi)許多大型礦井及煤炭轉運生產(chǎn)線上廣泛運用,獲得了良好的社會、經(jīng)濟效益。 XZG型給料機是90年代具有先進水平的新型給料設備。由北京有色冶金研究總院、東北工學院等在吸收國內(nèi)外先進技術基礎上研發(fā)而成。92年,在世界第二、亞洲第一的大型銅業(yè)基地-德興銅礦進行工業(yè)性調(diào)試,同年12月通過中國有色總公司的技術鑒定,94年獲國家五部委頒發(fā)的國家級產(chǎn)品證,與國內(nèi)原有設備相比,XZG型給料機有顯著優(yōu)點。采用了雙質體近共振慣性振動原理。采用橡膠剪切給力,具有設計合理、結構緊湊、衡壓平穩(wěn)啟動、不受槽體物料載重和卡死的影響,而且省力、無噪聲、省電、給料量大,可以配置無級變頻器,實現(xiàn)變頻給料、配料,遠距離微機操作控制,常年無需維修,主振剪切膠簧10年無需更換。目前,已在國內(nèi)重大項目工程中廣泛采用,江西德興銅礦、安徽銅陵公司、安慶銅礦、招遠金礦、上海寶鋼、三峽工程、神華大柳塔洗煤廠、榆家梁、孫家溝、充州濟寧二號井以及各大礦務局等。它采用懸掛、座式等配置,便于工藝布置及空間利用。該機型由槽體、激振部兩大部分組成,主振部分是激振部。一臺振動電機,水平裝置在平衡體后立板上,剪切橡膠彈簧上下單排或雙排布置。由下壓板通過螺栓連接在平衡體上,再由左右側板與槽體連接。原理是,振動電機偏心作用力通過上下固定在平衡體與壓板上的剪切膠塊把力剪切傳遞到槽體,實現(xiàn)均勻給料。振頻960次/ min,振幅可達2- 12 mm。在十多年的推廣應用中,得到廣大用戶的一致好評,正在日益發(fā)揮作用。被公認為是目前最先進的產(chǎn)品之一。但是,以雙質體理論設計配置,整機質量較其它產(chǎn)品大,制造費用較貴。特別是防爆型給料機,因防爆振動電機價格較高,在推廣中遇到了廉價給料機的挑戰(zhàn)。但有遠識的企業(yè)家、工程技術人員還是看重了其可靠性和先進性,正在不斷占領各個行業(yè)的給料機市場。我們從以上各類給料機的發(fā)展歷程可以看出,我國振動給料機順應國外給料機發(fā)展模式:振動給料機可靠耐用,維護量少,生產(chǎn)效率高,便于自動化管理;大型化可提高處理能力,適應高產(chǎn)高效集約化生產(chǎn)需要,實現(xiàn)微機自動化控制、動態(tài)分析與監(jiān)控技術相結合;拓展各機型的適用范圍,以滿足不同物料運輸?shù)男枰?,降低動力消耗和噪聲,更加環(huán)保和人性化設計。但是,我們不難發(fā)現(xiàn)整個民族工業(yè)發(fā)展息息相關,我們要倍加呵護。由于我國各地經(jīng)濟發(fā)展不平衡,先進技術應用還要經(jīng)過一個艱苦的認識過程,傳統(tǒng)觀念的封閉與經(jīng)濟欠發(fā)達地區(qū)的財力都會影響我國振動給料設備的發(fā)展。因此,要想使我國的給料設備趕超世界水平,還有待各方面的共同努力。直線振動篩與下面我所介紹的振動給料機的工作原理有異曲同工之妙,我們不妨先看看直線篩的工作原理圖:ZXS系列直線振動篩利用振動電機激振作為振動源,使物料在篩網(wǎng)上被拋起,同時向前作直線運動,物料從給料機均勻地進入篩分機的進料口,通過多層篩網(wǎng)產(chǎn)生數(shù)種規(guī)格的篩上物、篩下物、分別從各自的出口排出。具有耗能低、產(chǎn)量高、結構簡單、易維修、全封閉結構,無粉塵溢散,自動排料,更適合于流水線作業(yè)。 圖1-1直線振動篩的工作動態(tài)效果圖及其平面圖 2 給料機的工作原理振動給料機又稱為振動喂料機。振動給料機在生產(chǎn)流程中,可把塊狀、顆粒狀物料從貯料倉中均勻、連續(xù)、定時地給到受料裝置中去,在砂石生產(chǎn)線中可為破碎機械連續(xù)均勻地喂料,并對物料進行粗篩分,廣泛用于冶金、煤礦、選礦、建材、化工、磨料等行業(yè)的破碎、篩分聯(lián)合設備中。電機振動給料機是利用兩臺偏心振動電機的同步原理,產(chǎn)生合力,通過周期振動,從而推動給料槽內(nèi)的物料做拋擲或滑行運動,用于把塊狀、顆粒狀及粉狀物料從貯料倉或其它貯料設備中均勻、連續(xù)或定量地給到受料設備中,適應于自動配料、定量包裝和自動控制。它的性能特點是:振動平穩(wěn)、工作可靠、壽命長;可能調(diào)節(jié)激振力,可以隨時改變和控制流量,調(diào)節(jié)方便穩(wěn)定;振動電機為激振源,噪聲低,耗電小,調(diào)節(jié)性能好,無沖料現(xiàn)象。結構簡單,運行可靠,調(diào)節(jié)安裝方便,重量輕,體積小,維護保養(yǎng)方便,當采用封閉式結構機身時可防止粉塵污染。ZG型振動給料機采用的是座式安裝,可直接安裝在基礎上,或鋼結構的底架上。設備安裝后比較平穩(wěn),但要求基礎平整。 圖2-1 自同步振動給料機結構與工作原理 1槽體 2激振電機 3減振器從圖中可以看到,振動給料機的激振器是由一對參數(shù)接近相同的激振電機組成的,兩臺激振電機通常平行安裝于槽體的后部兩側或槽體的下方,并對稱于給料機的縱向對稱平面。兩臺激振電機的軸線與槽底平面所夾的角度和所需的振動方向角互為余角。兩臺激振電機的軸線也可以與槽體的對稱平面相垂直,安裝在給料機槽體的后部。這時,不應破壞整機關于槽體縱向對稱平面的對稱性。在這種情況下電機底座與槽底平面所夾的角度也應和所需的振動方向角互為余角。根據(jù)自同步原理,兩電機啟動后,將很快就進入同步狀態(tài),即以同一轉數(shù)運轉,兩電機的偏心塊所產(chǎn)生的慣性力在兩軸心連線上相互抵消,而在與兩軸心連線相垂直的方向上疊加為激振力。這是按規(guī)律變化的,此激振力使振動給料機獲得輸送物料所必須的振動。 3 承載構件的結構設計承載構件系指振動給料機直接承載物料的部件,它是給料機的重要組成部分,根據(jù)承載構件尺寸的大小和被輸送物料的性質,一般用210mm厚的炭鋼、低合金結構鋼或不銹鋼焊成。本設計都采用Q235,它是很好的焊接材料。3.1 承載構件的型式振動給料機的承載構件,根據(jù)具體使用要求通常設計成槽式和管式。在這里,采用的是通用型式槽式。槽式多是敞開的,也可以做成密封的,以防止粉塵外溢或環(huán)境污染。槽體的截面分為矩形的、梯形的和三角形的,槽底有平底和弧形底兩種。因為槽體直接參與振動,它的質量(或重量)大小直接影響到所需要的激振力和消耗功率的大小。承載構件愈重則功率消耗愈大,因此承載構件重量輕些才好。槽體始終處于較高頻率的振動狀態(tài)下,為了避免在共振時振幅增大而造成構件的疲勞斷裂,要求槽體有較高的剛度。為了減小承載質量并增加它的剛度,通常在槽體外面焊接加強筋,以增加截面的慣性矩,本設計中,槽體的設定長度為1.5米。3.2 承載構件的剛度為了使承載構件在振動條件下經(jīng)久耐用,在槽體設計時僅僅考慮強度是不夠的,還應保證構件有足夠的剛度。(1) 整體剛度在計算槽體的整體剛度時,可將槽體看成是支承于彈簧上的彈性支承梁。該梁的一階彎曲固有頻率可近似按照下式計算: 式 (3.1)式中 一階彎曲固有頻率,; 槽體單位長度質量,; 彈性模量,; 截面慣性矩,; 槽體的長度,。為了使槽體有盡可能高的一階固有頻率,可以采取以下措施。盡量減輕槽體重量,使槽體的截面慣性矩大而槽體長度短。(2) 局部剛度 因為槽體的某一局部剛度不足也會引起局部共振,因此除了上述整體剛度的要求之外,還要求槽體的各個局部也具有足夠的剛度。 對于懸臂筋板的一階彎曲固有頻率可按下式近似計算: 式 (3.2)式中 一階彎曲固有頻率,; 筋板厚度,; 筋板高度,; 材料的彈性模量,; 筋板材料的密度, 。各階固有頻率之比為: 3.3 槽體主要尺寸的確定本設計中,槽體長度L設定為1500mm,寬度B為1100mm。振動給料機中用于配料定量時為保證給料均勻,防止物料自流應水平安裝;如進行一般物料連續(xù)給料,可下傾10安裝;對于粘性物料及含水量較大的物料可下傾15安裝。推力板(傳動板)是傳遞激振力的重要構件,應有足夠的剛度。兩推力板之間的距離 ,推力板在激振力作用下不應有彈性變形,以保證物料在整個槽寬上的輸送速度一致。槽幫的高度(或深度)一般不宜太高或太低,推薦為450。為了使激振力能夠準確地通過槽體質心,使力臂為0,以防止機體產(chǎn)生搖擺振動,這就牽涉到槽體質心的位置計算。應該指出,槽內(nèi)帶有物料時的機體質心,也就是指負載后的槽體質心與空載的槽體質心是不重合的。在設計時,激振力作用線必須通過負載時槽體的質心。槽體的質心坐標可由下式求出: 式 (3.3) 式中 槽體各零件距坐標原點O的距離; 槽體上各零件的重量; 槽體重心的坐標。 3.4 振動篩板的結構設計振動篩是利用振動的多孔工作面將顆粒大小不同的混合物料按粒度進行分級的機械,這種分級作業(yè)叫做篩分。篩分工作一般適用于尺寸為1300mm或更細物料(達0.05mm,甚至更小)的分級。當用于分級時,一層篩面可獲得兩種產(chǎn)品;用n層篩面分級可獲得n+1種產(chǎn)品。根據(jù)篩分任務的不同,篩分作業(yè)可分為以下幾種:(1)獨立篩分。篩分后的產(chǎn)品成為成品的篩分稱為獨立篩分。(2)預備篩分。為下一步加工而進行的篩分稱為預備篩分。在選礦廠中,如采用重力選、電磁選等選礦方法時,要求礦石有一定的粒度范圍,因而,在選別之前,須將礦石分成若干等級,以利于選別作業(yè)有效地進行。(3)輔助篩分。這種篩分作業(yè)是和破碎作業(yè)聯(lián)合在一起的。其目的是當?shù)V石進入破碎機之前,將已符合要求的不需要破碎的合格產(chǎn)品篩出;或是對破碎機破碎后的產(chǎn)品進行檢查,篩出過大的不合格產(chǎn)品送回破碎機中繼續(xù)進行破碎。前者稱為預先篩分,后者稱為檢查篩分,若同時執(zhí)行預先篩分和檢查篩分的任務,則稱為預先檢查篩分。本設計中,振動篩板實現(xiàn)的就是輔助篩分。 圖3-1 三種篩分方式示意圖 (a) 預先篩分 (b)檢查篩分 (c)預先檢查篩分 (4)其他篩分。如脫水、脫介、脫泥等。對中等料層厚度采用的是普通篩分法,對物料進行篩分。它的特點是:(1) 料層厚度一般為篩孔尺寸的36倍;(2) 篩面層數(shù)為12層;(3) 物料顆粒的透篩是在篩面連續(xù)振動的情況下按照篩孔的大小進行的。(4) 篩孔尺寸a與篩下物的最大顆粒尺寸d的關系:圓孔:a=1.31.4d,方孔:a=1.11.13d,長方形孔:a=0.70.8d 。此設計中采用的是方形孔,沖孔而成。篩面是篩機的主要工作部件。對篩面的基本要求是:有足夠的強度,最大的有效面積,篩孔應不易堵塞,在物料運動時與篩孔相遇的機會較多。這是保證篩面有較好的工作可靠性、工作效果和使用壽命的條件。篩板是一種比較牢固的篩面,主要用于大中塊物料的篩分作業(yè)中。篩孔在25mm以上的大塊分級,應當采用篩板。這樣篩面的壽命較長,對篩分效果影響不大。其開孔率可用下式計算: 式(3.4)式中 開孔率,%; 篩孔直徑,mm; 篩孔間的最短距離,mm。按照經(jīng)驗, 的大小可用公式 確定。經(jīng)計算,篩板的開孔率為50%。 4 工藝參數(shù)的選擇4.1 給料機的長度及寬度 給料機的長度依照用戶煤倉的尺寸、給料機的替代及物料的自鎖條件等三方面來確定.本機長度定為1 500mm,寬度則確定為1 100mm。4.2 振幅和頻率為了選擇最佳下列參數(shù).先進行物料運動分析篩面上有單顆物料W.在振動過程時作用在W上的力。如圖4-1所示: 圖4-1 物料機上物料受力分析圖中 物料在X方向的慣性力,N;作用給物料W的拋射力,N;F磨檫力,N; N正壓力,N;G物料重,N; G重力加速度,918cm/。按照達輪培爾原理,可建立以下微分方程式: 式 (4.1)式中 給料機安裝傾角 ; 給料機拋射角 ; 振幅;振動電機角速度 。 物料W可能有3種運動狀態(tài)前滑:它增加給料機地板摩擦,一般不用;后滑:無意義;跳起:給料機下作需要使物料拋起.其條件為: ,這時N=0,F=0,將(4-1)式除以得: 式 (4.2)即,當為時拋射力為最大,這時令,稱為振動強度,一般KI時,料槽將在超共振區(qū)工作,增加輸送物體后,m增加,將使阻尼值。增大令振幅下降,而P降低,則值增加,振幅更加大,影響振動系統(tǒng)的工作穩(wěn)定性。 6 振動給料機電機功率的計算確定慣性振動給料機及振動篩電機功率參數(shù)過程中,傳動率的合理選擇和計算是一個十分重要的問題,它不僅是慣性振動給料機及振動篩正常運行的重要條件,而且也是合理電能消耗的重要條件。在傳統(tǒng)的工程設計中,慣性振動給料機及振動篩電機功率參數(shù)的確定是由經(jīng)驗估算來確定的。例如:由礦院設計的某石灰石礦破碎篩分系統(tǒng)規(guī)模為年處理礦石4000kt/ a,其粒度要求見表1。破碎篩分系統(tǒng)工藝流程是,采礦選用電鏟裝車,運至破碎篩分系統(tǒng)的石灰石原礦粒度為1000-2000mm結合產(chǎn)品粒度要求,設計采用粗、中和細碎閉路二段破碎流程。其產(chǎn)品粒度界限圖見表6-1:表6-1產(chǎn)品粒度界限表從表6-1中可以看出,振動給料機及振動篩在破碎系統(tǒng)中使用頻率較高,對產(chǎn)品的質量起重要的作用。振動給料機及振動篩電機功率的計算方法有好幾種,其中一部分計算方法屬于經(jīng)驗公式,它們只能對這類設備的功率選擇作初步的確定。一般誤差較大,如果要合理計算其功率,必須分析這類機械的啟動過程,才能得出較為合理的電機功率數(shù)據(jù)。而這種計算結果在該石灰石礦破碎系統(tǒng)的工藝流程的改造得到驗證。在已完成的工程設計中,對振動給料機及振動篩的選用,其中電機功率的確定未進行過詳細的計算,只是根據(jù)處理量憑經(jīng)驗公式來確定振動給料機及振動篩的電機功率參數(shù),使得工程設計中確定電機功率的理論依據(jù)不是很充分。隨著工藝水平的不斷進步,振動給料機及振動篩的電機功率參數(shù)的計算方法也有了一定的改進。通過分析給料機及振動篩的啟動過程,計算出合理的電機功率數(shù)據(jù),是一種相對完善,也較容易實現(xiàn)的一種計算方法.下面對這種計算方法進行簡單的介紹。6.1 振動給料機及振動篩啟動過程分析 振動給料機及振動篩的正常工作是由帶偏心質量的振動器馭動其機體產(chǎn)生連續(xù)的振動,使物料得到有效的輸送或篩分。而振動器的核心部分是以一定的速度旋轉的偏心塊。當振動給料機及振動篩啟動時,振動器的偏心質量在規(guī)定時間內(nèi),由靜止達到工作轉速,實現(xiàn)正常工作,完成全部啟動過程。 要實現(xiàn)這個啟動過程必須要在振動器的偏心質量上加一個最大的轉矩,以克服振動器的阻力矩、靜轉矩和加速力矩,來實現(xiàn)振動給料機及振動篩的正常起動,穩(wěn)定運轉的工作狀態(tài)。設最大轉矩為 ,則 式(6.1)式中 使振動器的偏心質量m在規(guī)定時間達到工作轉速的角加速度所需的力 矩,N .m; 克服振動器的阻力及參振質體mR質體的靜轉矩所需的力矩,N .m; 式(6.2)式中 振動器的偏心質量旋轉角速度,r/ min; t 時間,s; 式(6.3)式中 n振動器的偏心質量旋轉速,r/ min 。 = / dt 式(6.4)式中 振動器的轉動慣量,; ; 式(6.5)式中 參振質體的質量,kg; D 推算的環(huán)動直徑,m。起動過程的角加速度是變化的,但在規(guī)定的起動時間內(nèi),可取其平均值。 式(6.6)所以, 式(6.7)在(6.1)式中的是由振動器的阻力矩和靜力矩組成。即 式(6.8)由于較小,可以忽略,計算時可以認為 式(6.9)由于振動篩式振動給料機的參振質體在振動過程中能量的輸入和輸出、電機功率實際上是不平衡的,所以要考慮一個不均衡系數(shù)K,所以 式(6.10)式中 K不均衡系數(shù),K = 0. 4 0. 5; 振幅,m。 所以 式(6.11)6.2 電機功率的計算 電機功率一般以額定轉矩,計算,即 式(6.12)式中 u額定電壓,V; 電壓降時的最大電壓,V。則電動機功率P為:, 選取 kw。 7 強度校核7.1 焊接校核7.1.1 焊接介紹薄板結構的搭接焊接可以采用接觸焊(點焊)和滾焊(縫焊),本設計所有焊接都采用縫焊。焊點的直徑d 可根據(jù)被焊對象零件的厚度來確定;d=1.2S + 4mm, 而且此直徑不應大于d=1.5S+5mm,式中S是被焊元件的最小厚度。 傳動板 S= 12mm 所以 d=1.212mm +4mm=16.4mm d=1.512mm +5mm=23mm 那么 d=16.4-23mm 取d=18mm。 其他鋼板 S=8 mm 所以 d=1.28mm +4mm=13.6mm d=1.58mm +5mm=17mm 那么 d=13.6-17mm 取d=15mm。推薦焊接點間的距離 a=3d7.1.2 焊接的質量檢查 為了保障機械制造中產(chǎn)品的可靠性,應該對焊接件進行全部檢查或者抽樣檢查。檢查的方法有外觀目測以及破壞性方法和非破壞性(無損)方法幾種。本設計采用運行長時間來試機用來檢驗焊接質量。7.1.3 靜載荷作用下焊接的計算對接焊縫的強度計算是把被聯(lián)接零件看成一個整體零件而按其名義截面(不考慮焊縫加厚)進行的。給料機材料均為Q235。拉應力 式 (7.1)式中 外載荷; 焊縫的長度; 被聯(lián)接零件的厚度; 焊縫拉伸許用應力,通常,取。表7-1 靜載荷作用下焊縫的許用應力焊接類型焊接的許用應力拉伸時受壓時剪切時自動焊,在保護性氣體介質中焊,接觸焊065普通焊條手工焊0906點接觸焊05 =32.3MPa 0.9 =0.9235=211.5MPa滿足要求。7.1.4 交變載荷作用下的強度計算當焊聯(lián)接件承受載荷時,如果循環(huán)的平均應力和應力幅長正比的增大,那么強度安全系數(shù)應為: 式 (7.2)式中 絕對尺寸因素影響后材料的疲勞極限; 有效應力集中系數(shù);取1.2;不對稱循環(huán)對疲勞強度的影響系數(shù),對于低碳鋼的對接焊聯(lián)接,取0.15。計算得:所以滿足要求。7.2 橡膠彈簧7.2.1 橡膠彈簧特性: 橡膠彈簧彈性模量小,形狀不受限制,各方向剛度可以自由選擇,容易達到理想的非線性特性,同時可承受多方向的載荷。本設計采用支承用橡膠彈簧,尺寸采用120120,橡膠彈簧橡膠硬度為50HS,查表矩此彈簧承受垂直載荷為94kN ,完全滿足設計要求。彈簧內(nèi)徑為38。 8 變頻器的調(diào)速方式及合理選擇 8.1 引言經(jīng)歷了20世紀70年代中期的第2次石油危機之后,人們充分認識到了節(jié)能工作的重要性,并進一步重視和加強了對交流調(diào)速技術的研究開發(fā)工作。隨著同時期電力電子技術的發(fā)展,作為交流調(diào)速系附錄EV2000 serieses transducer machine in the fountainSimmonsetal.,1998.Carrying on sieving in Kunming now again of several disaster in the family transducer the machine the sale the brand, comparison, end picked out AIMO to living E-V2000 seriates to change a transducer machine product. Through comprehensive an-alibis comparison, the AIMO livings EV2000 seriates to change a transducer machine, having three greatest advantages: Have another use while using a high perform-acne, have another procedure to turn a control; Two is the product dependable fun-action best: Three is an EV2000 is a kind of price to compare a very high and econ-omic type a product.AIMOS livingsing EV2000 serieses to change a transducer machine is to adopt a special control method a realization high torque , high accuracy, the breadth adjusts to drive soon of, it satisfy in general use change a transducer machine a high performance to turn of trend;Having the same kind product of outrun defends to jump brake function and adapts bad charged barbed wire net, the ability of temperature and dust, raised the credibility of the product biggest;AIMOS livingsing EV2000 serieses to change a transducer machine is customer in general use need and customer characteristic need, the professions need is organic to combine of creative type product, it practical PI, simple PLC, the vivid importation exportation carries son, the pulse frequency gives to settle, have a power fail with shut down a parameter storage choice, frequency give settle passage and movement orderany passage to bind, zero transducers return bad control, the lord assists to settle control, put a transducer control, settle long control etc., turn a solution for the integral whole that the equipments manufacturing industry customer provides a high integration degree to lowering system cost, raise the system credibility to have tremendous value;The AIMO livings EV2000 serieses to change a transducer machine to pass excellent turn the PWM control technique and electromagnetism and permit sex overall design, satisfied customer biggest to apply the amenity low noise, the environmental protection request of low electromagnetism interference.1.The spot installs the movement design of circumstance and fountain electricity circuit a request physically1.1 spots investigation fountain installs a circumstance physicallyThat fountain covers area about 200 square meters, tube road, submersible pump, spray a mouth, underwater colourful light, keep pond to repair etc. have been already completed work.The fountain whole shape for oval, spray water system is controled part by six sets of electricities to constitute:Group 1 is just central to establish 1 to keep a spray type to spray a mouth independently in the fountain pool, supplying water submersible pump one set, power 5.5 KWs;Group 2 is just central to be established a line of straight lines form array by ex- position to keep a spray type to spray a mouth in the fountain pool, supplying water submersible pump two sets, power 5.5 KWs 2.2 KWs;Group 3 the position establishes a set of double rhombus array to keep a spray type to spray a mouth after the fountain pool just central depend, supplying water submersible pump two sets, power 4 KWs 3 KWs;Group 4 establishes 1 turn to follow side oval an array to keep a spray type to spray a mouth in the whole shape oval edge of the fountain fountain pool, supplying water submersible pump three sets, power 3 KWs 3 KWs 5.5 KWs;Group 5 keeps pond catchment to use submersible pump work two sets for the underground, power 2.2 KWs 2.2 KWs;Group 6 is the fountain pool underwater colourful light set, the power adds up a 4 KWs.The fountain electricity controls building position a constitution Be being apart from fountain to keep a pond submersible pump the place of 60 meters, the pedestal submersible pump power cable adopts an oak set copper coreeach time three core10 square cables follow ground the ditch conceal cover up to spread to establishThe fountain uses to keep pond to establish for the underground type covered sewerage, ising divided into two or so pond, dark pond bottom depth about 4 meters.The top submersible pump is established in two or so dark pond bottoms respectively.1.2 fountains spray water shape electricity circuit to circulate a design a requestGroup 1 just central independence spray type lord sprays a mouth to spray the water design height as 6 meters, after switching on spray water shape to keep constantly, until shut down. Group 2 fountain pool is just central to depend an ex- position straight line form array to keep a spray type to spray a mouth, having in order perpendicular request to spray water shape, while spraying water water type from have no water to go up to 4 meters gradually and keep 1 declined to to dont spray water to appear gradually after minute. Group 3 fountain pool keeps a spray type to spray a mouth after ising just central to depend the double rhombus array of position, requesting in order after Group 2 complete perpendicularity to spray water shape, while spraying water water type from have no water go up to 3 meters gradually and keep 1 declined to to dont spray water to appear gradually after minute. Group 4 oval array which follows an outside turn keeps a spray type to spray a mouth, requesting in order to tilt to one side 75 degrees after Group 3 complete to inside the parabola type spray water shape, the start nature of the adoption submersible pump sprays water, water type sprays 4 meters in height and keep 3 stop spraying water after minutes.Above-mentioned Group 2, Group 3, Group 4 submersible pump design becomes auto in proper order circulation, Group 1 and Group 6 underwater colourful light set design in order to switch on to start, shut down stop work. Group 5 keeps pond catchment to use a submersible pump, designing an adult in order to start, shut down to control.2.The fountain sprays water shape electricity circuit to circulate a control design to conceive outline 2.1 Group 1s spray a mouth, Group 2 sprays a mouth, Group 3 sprays a mouth, Group 4 sprays a mouth, Group 6 underwater colourful light set adopts in fixed time a machine to always control, starting in fixed time/shut down to control.Auto in proper order circularly the part is alone another to do to control electric circuit, easy to maintain an observation. 2.2 Group 1s of submersible pumps and Group 6 underwater colourful light set, in addition to adopting in fixed time the machine always controls, the another line designs 1 to switch on to start respectively and independently, shutting down to stop work mode, easy to maintain an observation.Group 5 keeps pond catchment to use a submersible pump to also design independence of switch on to start, shut down to stop work mode.Three independence switches on to start, shutting down stop work mode, adopt contact machine from protect to move/stop the circuit can immediately attain a purpose.2.3 Group 2, Group 3, Group 4 design become the auto is in proper order circulation.Among them, Group 2 circulation with in proper order auto start, adopting above-mentioned 2.1 item in of in fixed time machine, start control in fixed time to the early start of starting the submersible pump, promise circulating movement with the stop signal of the control circuit of the Group 4 submersible pump contact machine. Group 2 wants an au to attain to spray water water type from have no water to go up to four meters gradually and keep one after minute declined to to dont spray water gradually have to adopt to change a transducer machine of frequency modulation, adjust to press, adjust soon function then can attain a purpose.Is the 5.5 KWs 2.2 KWs according to Group 2 submersible pump power=the actual circumstance with 7.7 KWs, living the adoption EV2000-4 of the EV2000 series characteristic T0055 Gs/0075 Pses to change a transducer machine a realization to spray a water shape according to the AIMO .The exploitation changes the transducer machine CN6 to carry the son FWD mark number to carry to connect to go into in fixed time a machine to start control signal circuit in fixed time, attain a Group 2 of purpose that submersible pump starts.2.4 Group 3s of double rhombus arrays keep a spray type to spray a mouth, attain in order after Group 2 complete the perpendicularity spray water, while spraying water water type from have no water to go up to 3 meters gradually and keep 1 declined to to dont spray water gradually after minute.Have to also adopt to change a transducer machine of of frequency modulation, adjust to press, adjust soon function then can attain a purpose.Is the 4 KWs 3 KWs according to Group 3 submersible pump power=the actual circumstance with 7 KWs, living the adoption EV2000-4 of the EV2000 series characteristic T0055 Gs/0075 Pses to change a transducer machine according to the AIMO .Group 3 submersible pump auto is in proper order circulate start control signal, the CN7 which adopts a Group 2 of submersible pump to change the transducer machine EV2000-4 T0055 Gs/0075 Pses carries son TA, the TC mark number carries to connect go into start control signal circuit, attain a Group 3 of purpose that submersible pump starts.2.5 Group 4s of oval arrays keep a spray type to spray a mouth, tilting to one siding 75 degrees after Group 3 complete in order to inside the parabola type spray water, adopting a submersible pump start nature to spray water, water shape sprays 4 meters in height and keep 3 stop spraying a water request after minutes.Adoptions getting in touch with a machine a control circuit can immediately attain a purpose.The CN7 which gets in touch with a machine control the start of the circuit a control signal an adoption Group 3 submersible pump to change a transducer machine carries son TA, the TC mark number carries to connect into a start a control signal circuit, attain a Group 4 of purpose that submersible pump starts. 2.6 because of Group 2, Group 3, Group 4 wants to design auto circulation under the sistuation that switch on.So need not to receive the stop signal of Group 4 submersible pump contact machine control circuit a Group 2 of submersible pump control change the transducer machine CN6 to carry the son FWD mark number to carry, then can attain three sets of automatically circulating purposes.3.the system adjust to tryThis kind of fountain sprays a water circuit control of the shape electricity the system of the movement to adjust to try a key to lie in Group 2, Group 3 system constitution which change a transducer machine.Spray other main spare part all adoption import piece within control of the water electricity circuit to install in this kind of fountain, insure to guarantee complete success.Before establishing AIMO to living the function parameter that the EV2000-4 T0055 Gs/0075 Pses change a transducer machine, the customer has to read its user manual and usage manual in detail.Should change a transducer machine to try according to the user manual multi-function and multipurpose change a transducer machine, used for a fountain control the movement of the submersible pump, applying should change a transducer machine in of seldom one part of function constitution parameter, greatly parts of parameters all dont need to be established perhaps say pressing original factory cans not establishes then.That fountain controls the parameter ofwith parts of constitutions as follows:F0.03 circulate an order a passage choice:(Carry a sub- movement order)F0.08 model choices:1(water pump load)F0.09 torque to promote:30%F0.10 acceleration time:6.0SF0.The 13 times limits frequency:2.00HZF2.01 start frequency:30.00HZF2.02 start frequency to keep time:10SF4.00 simple PLCs circulate a way choice:1000(started from the first stage, the single circle shut down behind.)F4.02 stages 1 circulate time:1.0SF4.04 stages 2 movement time:6.0SF4.06 stages 3 movement time:1.0S F4.08 stages 4 movement time:6.0SF4.10 stages 5 movement time:1.0SF4.12 stages 6 movement time:6.0SF4.14 stages 7 movement time:6.0SF7.12 output a function choice after the electric appliances:11(the PLC completes designation circularly)The FH.01 sumses settle power:7.5KWThe FH.02 sumses settle electric current:15AFH.09 parameters from whole settle:2(the electrical engineering revolve action)4.summary and result are analytical Was sprayed by this fountain water circuit control of the shape electricity the system of the movement adjust to try, the fountain sprays water shape result basic attain an owner management a staff to request a purpose.This kind of fountain sprayed water shape electric circuit to adopt two set EV2000-4 T0055 Gs/0075 Pses to change a transducer machine, two sets changed the function parameter that the transducer machine sprays water shapes to all need through many times again and again adjustment to change a transducer machine, just can be basic to complete an ideal water type.Always feel in the system adjust try the process F2.05 straight lines accelerate the function not enough ideal, expressing of actual water type difference is too big.Press ideal acceleration process, while spraying water shape water type from have no water go up to the apogee gradually of process, accelerating function straightly should is the process that an integrity didnt lack, can actual circumstance indeed BE:Group 2, Group 3 submersible pump starts circulating have no water jet, about 10 just see ground jet water go to some height suddenly just go up gradually to attain apogee thus behind after second.This blemish process many times regulate stage movement time again and again, F2.01 start frequency, F2.02 start frequency to keep time and F0.09 after torque to promote all not enough ideal, the sprays water not enough high, the has together stairs.Regulate this stairs of high and low although can attain standard water type, cant promise the height of water type, is really a slight imperfection some regrets.After the event through very long-playing consultation understanding the circumstance study with iterative thinking, getting a conclusion finally:Appear a top suddenly ground jet water to go to some an a little bit high, then just go up to the apogee gradually, this blemish not ideal reason, is because power and discharge of submersible pump install not enough just result in the fountain spray water greatly not enough high.So the whichever fountain sprays power and discharge of the water submersible pump used in shape to install, is all key place that the fountain sprays water shape.If power and discharge of design submersible pump are too big, resulting in so gearing cost and usage the cost increase high.If power and discharge of design submersible pump install too small, reach so not a way the ideal result which spray water shape.ProgrammableLogicControllers(PLC),acomputingdeviceinventedbyRichardE.Morle-yin1968,havebeenwidelyusedinindustryincludingmanufacturingsystems,transportation systems,chemicalprocessfacilities,andmanyothers.AlthoughPCbasedcontrolhasstarted tocomeintoplace,PLCbasedcontrolwillremainthetechniquetowhichthemajorityof indu-strialapplicationswilladhereduetoitshigherperformance,lowerprice,andsuperiorreliabilityinharshenvironments.Moreover,accordingtoastudyonthePLCmarketofFrostandSulliva-n1995,anincreaseoftheannualsalesvolumeto15millionPLCperyearwiththehardwarev-alueofmorethan8billionUSdollarshasbeenpre-dicted,thoughthepricesofcom-puting hardwareissteadilydropping.TheinventorofthePLC,RichardEMorley,fairlyconside-rsthePLCmarketasa5-billionindustryatthepresenttime. ThoughPLCarewidelyusedinindustrialpractice,theprogrammingofPLCbasedcontrolsystemsisstillverymuchrelyingontrial-and-error.Alikesoftwareengineering,PLCsoftwaredesignisfacingthesoftwaredilemmaorcrisisinasimilarway.MorleyhimselfemphasizedthisaspectmostforcefullybyindicatingMoodyandMorley,1999,p.110: Ifhouseswerebuiltlikesoftwareprojects,asinglewoodpeckercoulddestroycivilization. Particularly,practicalproblemsinPLCprogrammingaretoeliminatesoftwarebugsandtoredu-cethemaintenancecostsofoldladderlogicprograms.ThoughthehardwarecostsofPLCsaredroppingcontinuously,reducingthescantimeoftheladderlogicisstillanissueinindustryso thatlow-costPLCscanbeused. Ingeneral,theproductivityingeneratingPLCisfarbehindcomparedtootherdomains,forinst-ance,VLSIdesign,whereefficientcomputeraideddesigntoolsareinpractice.Existentsoftwa-reengineeringmethodologiesarenotnecessarilyapplicabletothePLCbasedsoftwaredesignbecausePLC-programmingrequiresasimultaneousconsiderationofhardwareandsoftware.Th-esoftwaredesignbecomes,thereby,moreandmorethemajorcostdriver.Inmanyindustrial designprojects,morethanSO0/aofthemanpowerallocatedforthecontrolsystemdesignand installationisscheduledfortestinganddebuggingPLCprogramsRockwell,1999.Inaddition,currentPLCbasedcontrolsystemsarenotproperlydesignedtosupportthegrowin-gdemandforflexibilityandreconfigurabilityofmanufacturingsystems.Afurtherproblem,imp-ellingtheneedforasystematicdesignmethodology,istheincreasingsoftwarecomplexityin large-scaleprojects. 1.2ObjectiveandSignificanceoftheThesis TheobjectiveofthisthesisistodevelopasystematicsoftwaredesignmethodologyforPLCop-eratedautomationsystems.Thedesignmethodologyinvolveshigh-leveldescriptionbasedon statetransitionmodelsthattreatautomationcontrolsystemsasdiscreteeventsystems,astepwis-edesignprocess,andsetofdesignrulesprovidingguidanceandmeasurementstoachieveasuc-cessfuldesign.Thetangibleoutcomeofthisresearchistofindawaytoreducetheuncertaintyinmanagingthecontrolsoftwaredevelopmentprocess,thatis,reducingprogramminganddebu-ggingtimeandtheirvariation,increasingflexibilityoftheautomationsystems,andenablingso-ftwarereusabilitythroughmodularity.Thegoalistoovercomeshortcomingsofcurrentprogra-mmingstrategiesthatarebasedontheexperienceoftheindividualsoftwaredeveloper.AsystematicapproachtodesigningPLCsoftwarecanovercomedeficienciesinthetraditionalwayofprogrammingmanufacturingcontrolsystems,andcanhavewideramificationsinsevera-lindustrialapplications.Automationcontrolsystemsaremodeledbyformallanguagesor,equi-valently,bystatemachines.Formalrepresentationsprovideahigh-leveldescriptionofthebeha-viorofthesystemtobecontrolled.Statemachinescanbeanalyticallyevaluatedastowhetherornottheymeetthedesiredgoals.Secondly,astatemachinedescriptionprovidesastructured representationtoconveythelogicalrequirementsandconstraintssuchasdetailedsafetyrules. Thirdly,well-definedcontrolsystemsdesignoutcomesareconducivetoautomaticcodegenerat-ion-Anabilitytoproducecontrolsoftwareexecutableoncommercialdistinctlogiccontrollerscanreduceprogramminglead-timeandlaborcost.Inparticular,thethesisisrelevantwithrespecttothefollowingaspects.Customer-DrivenManufacturing .Inmodernmanufacturing,systemsarecharacterizedbyproductandprocessinnovation,becom-ecustomer-drivenandthushavetorespondquicklytochangingsystemrequirements.Amajor challengeisthereforetoprovideenablingtechnologiesthatcaneconomicallyreconfigureauto-mationcontrolsystemsinresponsetochangingneedsandnewopportunities.Designandoperat-ionalknowledgecanbereusedinreal-time,therefore,givingasignifi
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