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山東輕工業(yè)學院
畢業(yè)設(shè)計(論文)中期進展報告表
學院
機械與汽車工程學院
專業(yè)班級
機械08-2班
學生姓名
張淇翔
學號
200801011074
導師姓名
范維華
設(shè)計(論文)題 目
重力滾道輸送機阻尼裝置設(shè)計
根據(jù)設(shè)計要求和重力滾道輸送機阻尼裝置的性能參數(shù),在老師的指導下,前段時間主要完成了開題報告、英文翻譯、實習報告的工作,并查閱相關(guān)的資料,擬定了設(shè)計方案。初步完成了阻尼裝置基本機構(gòu)的設(shè)計,傳動機構(gòu)的設(shè)計,重力滾道輸送機的整體結(jié)構(gòu)圖。
為了防止輸送物下滑過快而造成的不必要的損失,應正確選擇輥道傾角。摩擦系數(shù)的選擇查閱了機械設(shè)計。
阻尼裝置,采用一套齒輪行星輪系傳動機構(gòu),確定了阻尼型式。傳動設(shè)計參考了機械設(shè)計與機械原理。
完成了重力滾道輸送機的總體結(jié)構(gòu)圖,對各個零件的布置有了初步設(shè)計并對阻尼裝置進行的設(shè)計。
根據(jù)總體設(shè)計圖中的輸送機參數(shù)對阻尼裝置的制動力進行計算,然后根據(jù)制動力對制動輥進行設(shè)計,計算出輸送機貨物的阻尼,從而確定輸送機貨物的限速范圍。
在工作過程中,自己的疑問在老師和同學的幫助下,基本上都得到了解決。在以后的設(shè)計中將繼續(xù)查閱相關(guān)資料,參考現(xiàn)有的設(shè)備對裝配圖進行優(yōu)化。同時繪制零件圖。
根據(jù)設(shè)計要求,在老師的指導下,最快最好的完成各項工作。
2012 年 05 月 28 日
指導教師評價意見
1.設(shè)計(論文)進展情況評價
(基本完成計劃、部分完成計劃、沒有完成計劃)
2.學生工作態(tài)度情況評價
(認真、一般、較差)
3.已完成設(shè)計(論文)質(zhì)量評價
(較好、一般、較差)
4.設(shè)計(論文)不足之處及改進意見
指導教師簽字:
年 月 日
注:每名學生填寫一份,并由指導教師填寫意見、簽字后,返還學生歸檔。
本科畢業(yè)設(shè)計(論文)
題目 重力滾到輸送機阻尼裝置設(shè)計
學院名稱 機械與汽車工程學院
專業(yè)班級 機械08-2班
學生姓名 張淇翔
導師姓名 范維華
2012年 6 月 7 日
- 1 -
山 東 輕 工 業(yè) 學 院
畢業(yè)實習報告
院系名稱 機械與汽車工程學院
學生姓名 張淇翔
專業(yè)班級 機械08—2班
指導教師 范 維 華
二○一二 年 四 月 二十二 日
實 習 情 況 一 覽 表
時間
地 點
實習內(nèi)容(講座、參觀、車間工作、總結(jié)等)
指導教師
備注
3月中旬
濟南煙草
配送中心
參觀精準分揀系統(tǒng)廠房
和儲藏煙草的倉庫
沈敏德
范維華
3月中旬
將軍集團濟
南卷煙廠
參觀了卷包車間,里面有數(shù)臺生產(chǎn)速度為1000支/分鐘的卷煙機和400包/分鐘的包裝機。盡管在卷絲車間有數(shù)臺規(guī)模巨大的生產(chǎn)設(shè)備,然而所有設(shè)備都可以通過中央控制室來控制
沈敏德
范維華
一、實習目的
大學四年即將結(jié)束,接踵而來的是找工作,畢業(yè),就業(yè)。壓力是如此的巨大,因為我們大學四年的學習并沒有給我們帶來實際的工作能力,也沒有絲毫的社會經(jīng)驗。利用畢業(yè)前的這一段時間,學校組織我們?nèi)⒓恿诉@次的集體實習,讓我們對社會,對工作有些許的了解,以便畢業(yè)之后工作時不至于捉襟見肘。
1、將理論與實踐相結(jié)合
通過這次的畢業(yè)實習,我們先后接觸與本專業(yè)相關(guān)的一些實際工作,對于工作所要求具備的專業(yè)理論知識和基本技能有個大體客觀的認識。實習過程中,要求我們通過聽取公司產(chǎn)品方面的講座學會理論和實踐有機結(jié)合,將我們平日里學的知識有機的結(jié)合到實踐中,然后更好的理解書本上的理論知識
2、找到差距,盡快縮短差距
實習時,我們會參觀一些有名企業(yè),期間公司負責人會給我們作講座,帶領(lǐng)我們參觀他們企業(yè)內(nèi)部的流程,員工工作的環(huán)境以及了解員工應該具有的專業(yè)技能。通過觀察,我看到了他們這些企業(yè)所要求員工所具備的那種職業(yè)素質(zhì),專業(yè)技能。而從我們身上體現(xiàn)出來的卻只是稚氣未退的學生氣,我們之間的差距明顯很大,我們畢業(yè)盡快調(diào)整自己使自己成為一名于社會需要,于企業(yè)合格的人才。
3、讓自己盡快轉(zhuǎn)變?yōu)樯鐣?
我們是即將畢業(yè)踏入社會的大學生,學生時代的稚氣已不適合于社會。由一個學生到一個職業(yè)人員的轉(zhuǎn)變過程,要求我們學會獨立、成熟和堅強,踏入社會我們必須學會擔負責任,腳踏實地,消除自己原本的擔憂,努力工作每一天。這次實習就是為了讓我們明白工作人要 擁有該有的素質(zhì)和能力。
二、實習內(nèi)容
馬克思哲學告訴我們,實踐是檢驗真理的唯一標準。在大學里,我們學習了很多的理論知識,不過我們總覺得很空,這正是因為缺乏實踐。實習正式將我們理論運用至實際生活中的機會。我們要想成為對社會有用的人才,要想在畢業(yè)后就可以找個好工作,實現(xiàn)自己的人生價值,就要重視好在大學里的實習。同時實習是一次不可多得的集體活動。平時在學校,除了上課,大家聚在一起的時間很少,缺乏生活上的專業(yè)上的必要交流,通過這次實習首先加強了同學們之間的凝聚力。
(一)將軍集團濟南卷煙廠
將軍集團濟南卷煙廠是國有大型企業(yè)。在特別人員的帶領(lǐng)下, 我們首先參觀了卷包車間,里面有數(shù)臺生產(chǎn)速度為1000支/分鐘的卷煙機和400包/分鐘的包裝機。卷煙機主要是將煙絲、濾棒和包裝紙卷在一起。在車間里,我們重點參觀了卷煙和包裝機,一萬多個零件組成的機構(gòu),高速運轉(zhuǎn)著,卷接、包裝設(shè)備自動化水平高。當時有臺機器出現(xiàn)了問題,由于整套裝置有阻塞、夾條、掉條檢測控制剔除系統(tǒng)工人師傅們很容易的排除故障。在參觀中,我們注意到了卷煙廠高度自動化的流水線和精確的質(zhì)量控制系統(tǒng)。當煙葉從整包被分離后,就開始進入加工階段。在經(jīng)過皮帶傳輸和振動運輸?shù)礁鱾€加工環(huán)節(jié)過程中,對流量有著嚴格的控制,皮帶上安裝有電子傳感器,能通過控制帶速來控制流量。盡管在卷絲車間有數(shù)臺規(guī)模巨大的生產(chǎn)設(shè)備,然而所有設(shè)備都可以通過中央控制室來控制。由于企業(yè)引入了現(xiàn)場總線,使得所有生產(chǎn)狀況都可以及時在中控室的電腦控制屏上顯示,包括動力部門的能源控制。
在現(xiàn)場,我們提出詢問了許多感興趣的問題,有關(guān)人員熱情細致地給予解釋,直到我們把整個工藝、生產(chǎn)流程了解為止。先進的生產(chǎn)設(shè)備,有序的生產(chǎn)現(xiàn)場,高素質(zhì)的操作員工,給我們留下了深刻的印象。卷包車間的卷接包、裝封箱、入庫全部實現(xiàn)了自動化。經(jīng)技術(shù)人員介紹,整個卷煙的生產(chǎn)流程如下:投料→開包→切片→回槽(提溫加水) →儲存兩個小時左右→脫水→卷煙→包裝。
通過實習發(fā)現(xiàn)的不足:原機裝封箱機速度不高,只能一臺裝封箱機對應一臺套卷包設(shè)備;二是離倉庫比較遠,不利于輸送并且在輸送過程中易造成破損;設(shè)備多并且控制比較復雜,操作和修理維護都需要大量的人力物力。
(二) 濟南煙草配送中心
在本次主要對濟南煙草配送中心兩家單位進行了詳細的實地的參觀和了解,著重對這家單位的物流配送體系,物流配送設(shè)備,在各個環(huán)節(jié)中所采用的現(xiàn)代化技術(shù)以及整個物流的資源配置系統(tǒng)進行了詳盡的認識和學習,因為兩家企業(yè)的設(shè)備與流程大體相近,現(xiàn)主要介紹濟南煙草配送中心。
濟南煙草配送中心隸屬于濟南煙草專賣局,濟南市煙草專賣局資本雄厚,在面對國際間激烈的煙草市場的發(fā)展競爭下,積極采用先進技術(shù),提高自己的信息化和自動化建設(shè)。尤其是以濟南煙草配送中心是作為新型的現(xiàn)代物流來建設(shè),坐落于濟南高新區(qū),與齊魯軟件園毗鄰,尖端的環(huán)境優(yōu)勢使得濟南煙草物流在收發(fā)配送方面獨具優(yōu)勢,同時濟南煙草物流中心通過網(wǎng)絡(luò)營銷、倉儲系統(tǒng)、分揀系統(tǒng)、線路優(yōu)化、GPS車輛監(jiān)控等信息系統(tǒng)技術(shù),使得濟南煙草物流中心的快速反應令人吃驚,對濟南地區(qū)的煙草配送在整個省內(nèi)行業(yè)乃至全國位居前列。
在濟南煙草配送中心主要參觀的是蘭劍物流為濟南煙草配送中心和煙臺煙草配送中心設(shè)計的煙草的倉儲系統(tǒng)、分揀系統(tǒng)和相關(guān)配送系統(tǒng)。在最開始的相關(guān)工作人員講解中我們了解到,煙草行業(yè)的競爭已經(jīng)不再局限于國內(nèi)煙草企業(yè)的競爭,跨國煙草企業(yè)的競爭壓力,讓中國煙草行業(yè)面臨巨大的挑戰(zhàn)。能否全面建立完善的煙草物流配送體系是煙草行業(yè)能否取勝的關(guān)鍵環(huán)節(jié),如何布局規(guī)劃配送中心的建設(shè)是煙草行業(yè)不得不去思考的問題。而此套物流方案解決了配送運營體系中的許多問題,實現(xiàn)了配送網(wǎng)點的合理布局,資源的優(yōu)化配置及時周轉(zhuǎn),提高了分揀的效率,大大降低了配送成本,總體上全面提升了煙草配送效率。電話訪銷、精準分揀、及時配送,提高了服務質(zhì)量和顧客忠誠度,減少了市場上非正規(guī)渠道卷煙的沖擊壓力,降低了物流成本。
根據(jù)老師和公司的安排流程,首先我們參觀了煙草倉庫的存儲系統(tǒng)。根據(jù)老師解說,此煙草存儲所用的倉庫是一個自動化立體倉庫。從貨物進入,分為兩種方式,一種是較為傳統(tǒng)的傳送帶運輸方式,但是效率仍然比人工快很多,用的比較多的是采取叉車托盤方式,整托盤煙草進入,然后進行倉庫保管即入庫。入庫過程是放到傳送帶由電腦全程操作,然后經(jīng)由由堆垛機,,然后通過工業(yè)計算機的指令發(fā)送到由操作人員預先設(shè)定相關(guān)程序,采用了RFID射頻識別技術(shù)可以讀取貨物的一切信息并將其分配到應有的位置,堆垛機按以獲取的信息自動將貨物準確無誤放在應在的位置。這種入庫工作流程幾乎是全自動化,只需要很少的幾個操作人員進行監(jiān)控和操作,而且效率很高,整個系統(tǒng)設(shè)計的全面合理,功能的密切統(tǒng)一和集中以及自動化的程度之高,都給我了很大的震撼。
接下來我們又去了分揀區(qū)的流水線查看其工作流程,剛開始,還沒有運作,只是聽講解,說這套系統(tǒng)屬于第三代煙草分揀系統(tǒng)(第四代也已經(jīng)研制完畢,尚未完善投入),分揀速度很快,以及精確的自動化包裝處理,聽得我們云里霧里,因為每條線上工作的也就四五個人,到底搞不清到底是怎么分揀這么多煙草滿足濟南市這么多客戶的訂單,稍等了幾分鐘,分揀線開始運作。根據(jù)一步步的流程,各種煙從不同的槽口被吐出,快速的經(jīng)過傳送帶,然后送到包裝臺,快速的進行包裝,然后電子顯示屏顯示下一個客戶的訂單數(shù)量,看似很簡單的流程,但是能夠控制的這么好,而且很精確的控制各類的煙草所要出具的數(shù)量,這一系列流程的整合,大大的提高了分揀的效率和精確度。全部自動一體化的完成,讓我深深感受到了現(xiàn)代化的信息系統(tǒng)所創(chuàng)造的價值。
最后關(guān)于煙草的配送系統(tǒng),由于GPS系統(tǒng)正在更新為3G,所以老師根據(jù)歷史資料進行解說,經(jīng)過查資料了解到,從整個煙草配送體系功能來看,本系統(tǒng)的在運輸方面,使用采用的電子地圖和GPS實時定位系統(tǒng),地圖上面標明了根據(jù)各銷售點的位置而設(shè)計好的最優(yōu)配送路線以及貨車采用的GPS定位系統(tǒng),可準確地了解每一輛貨車所在的位置及每次所消耗的時間,最終可準確的落實每一天的工作效率。同時對濟南煙草運輸線路的全面優(yōu)化,重新將濟南各個區(qū)域布局,減少各區(qū)間之間的疊加、沖突,使得交叉覆蓋面積最小交叉覆蓋率小于15%,路線得到更加合理的配置。物流信息,作為中樞神經(jīng)系統(tǒng)的物流信息在整個配送系統(tǒng)中起到的作用——計劃預測、動態(tài)分析、及時提供市場動態(tài)等相關(guān)內(nèi)容。濟南煙草配送信息這一塊做的比較到位,從計算機中能及時獲得相關(guān)的信息,為做出研究分析、制定相關(guān)策略提供了有力的保障。
本次實習總結(jié):通過這次實習,我更深刻的認識到物流這個概念的深度和廣度,以及在現(xiàn)實生活中,我們對物流的應用的層面,我發(fā)現(xiàn)課本的理論知識在實際過程中運用的很巧妙,因地制宜,靈活貫通給我了很大的啟示,也發(fā)覺了真正的實際操作中,我們對課本知識掌握的不夠扎實,也不夠全面,更沒有系統(tǒng)的思維和考慮。所以,我要學習的東西還很多,要真正領(lǐng)會課本的理論知識以及運用的方法和價值。
結(jié)論和建議:在濟南煙草中心,采用了現(xiàn)代信息化的設(shè)施和自動化的整合系統(tǒng),在很大程度上降低人員的勞動強度,節(jié)約生產(chǎn)成本,提高工作效率; 對于在煙草行業(yè)推廣應用新興的物流技術(shù),降低物流成本、實現(xiàn)配送現(xiàn)代化管理起了推動作用。然而在實際運作中,完備齊全的自動化系統(tǒng)會花費很大資金,希望在系統(tǒng)的設(shè)計方面能加以改善以節(jié)約成本,同時注重成本和效能,達到性能最優(yōu)化,從而可以推廣到其他物流企業(yè),真正的做好我國物流行業(yè)的領(lǐng)頭羊。同時在做煙草的同時,關(guān)于實地的配送運輸問題上,建議與部分物流相關(guān)企業(yè)進行合作,實現(xiàn)附帶運輸,以增加附加值和利潤,同時可以降低成本。
3、 實習總結(jié)
畢業(yè)前安排這次畢業(yè)實習使我收獲很多。老師帶領(lǐng)我們參觀一些卷煙廠和物流中心公司還有知名企業(yè)-張裕公司,深入到各公司的生產(chǎn)車間觀看員工的工作環(huán)境、產(chǎn)品生產(chǎn)工藝和研發(fā)設(shè)計產(chǎn)品。每到一個公司,負責人都會很詳細地給我們介紹公司產(chǎn)品以及它們利用的基本原理。這次畢業(yè)實習讓我了解專業(yè)有關(guān)的工作,對之前的畢業(yè)后從事的工作存在的疑惑也解除了。
在學校里,我們學習專業(yè)基本知識,缺乏專業(yè)實踐能力的鍛煉,離現(xiàn)實社會所需專業(yè)人才還有很大的差距,一直抱怨學校里學到的知識沒有實際利用價值,其實這都是借口,進入大學,我們首先學會獨立自學,然而我們這點沒有做好,更沒有人限制我們時間,是我們沒有利用好它。盡管實驗室條件有限,那些都是客觀理由?!盎畹嚼蠈W到老”這句話永遠具有現(xiàn)實意思。就像那位引導員說的,別把自己想象的太優(yōu)秀,真正踏入社會,你會發(fā)現(xiàn)很多問題。
畢業(yè)實習給我們畢業(yè)后的工作打下了一定的基礎(chǔ),讓我們懂得了工作跟學習兩碼事。馬上要踏入社會,進入工作崗位了,一個人需要迅速轉(zhuǎn)變角色,適應社會,去創(chuàng)造價值,把專業(yè)知識運用出來,并在工作上不斷學習,不斷創(chuàng)新。畢業(yè)實習讓我們學到了很多,感謝學校,感謝老師給予我們這次機會。
這學期的實習的實習使我對自己的專業(yè)有了直接具體的認識,在親身經(jīng)歷生產(chǎn)過程以前對機械這一行業(yè)的了解僅僅限于理論知識,對各種機床和生產(chǎn)設(shè)備也沒有接觸太多。實習之后,可以大致了解到現(xiàn)行的機械行業(yè)的運行情況,以及現(xiàn)在的制造業(yè)發(fā)展的動向。
指導教師評語:
實習成績:
指導教師: 年 月 日
山 東 輕 工 業(yè) 學 院
畢 業(yè) 設(shè) 計(論 文)任 務 書
機械與汽車工程學院 2008 級 機械設(shè)計制造及其自動化專業(yè) 姓名 張淇翔
題目 重力滾道輸送機阻尼裝置設(shè)計
主要內(nèi)容、基本要求、主要參考資料等:
1. 主要內(nèi)容:本設(shè)計任務是根據(jù)部分影象資料和網(wǎng)上查閱地資料進行研發(fā)工作,這次設(shè)計主要根據(jù)現(xiàn)代物流的要求,宗合考濾不同地作業(yè)項目,不同附件的按裝結(jié)構(gòu),對重力滾道輸送機阻尼裝置設(shè)計進行總體設(shè)計。要求制動可靠,能有效的防止輸送物下滑過快,配件具有一定的通用性,技術(shù)先進,結(jié)構(gòu)緊湊。此設(shè)計國內(nèi)尚無此種類型的定型產(chǎn)品,此設(shè)計國內(nèi)尚無此種類型的定型產(chǎn)品,屬開發(fā)設(shè)計。
2. 基本要求:對現(xiàn)代物流系統(tǒng)和重力滾道輸送機有基本了解,對阻尼裝置的工作原理有全面細致的理解,結(jié)合機械與物流等相關(guān)知識進行設(shè)計。完成重力滾道輸送機阻尼裝置設(shè)計圖紙,寫出設(shè)計論文。
3. 主要參考資料:設(shè)計手冊,部分重力滾道輸送機圖片資料,現(xiàn)代物流資料及機械相關(guān)資料。
完成期限:自 2012 年 3 月 15 日至 2012年 6 月 15 日
指導教師: 范維 華 教研室主任:
學院院長: 年 月 日
畢業(yè)設(shè)計(論文)開題報告
課題名稱
重力滾道輸送機阻尼裝置設(shè)計
課題類型
導師姓名
學生姓名
學 號
專業(yè)班級
一、 設(shè)計依據(jù)與目的
1、 物料搬運現(xiàn)狀
物料搬運是保證物流系統(tǒng)暢通有效運行的一個重要環(huán)節(jié),因此,完成物料搬運的輸送機械,也就成為物流系統(tǒng)設(shè)計規(guī)劃人員重點關(guān)注的項目。在固定路徑的運送中(如生產(chǎn)物流中,制品在各工序間的流動,倉儲系統(tǒng)中貨物的手法以及配送中心的揀貨發(fā)貨等),大都采用輥筒、皮帶或鏈條等型式的輸送機械,即單元負載輸送機,其中一滾筒型式較為常見。
2、 滾筒式輸送機分類
輥筒式輸送機根據(jù)其動力源不同可分為兩類。一類是動力式,即輥筒由動力帶動旋轉(zhuǎn)。通常以電動機為原動力。另一類為重力式輥筒輸送機。這類輸送機沒有動力,靠將輥道傾斜成一個適當?shù)慕嵌?,輥道上被輸送的物體在重力作用下自行下滑,因不需動力,結(jié)構(gòu)簡單等優(yōu)點,在短距離物料輸送中得到廣泛應用。
3、 設(shè)計目的
由于重力的作用,在重力滾道輸送機上,輸送物會愈滑愈快,產(chǎn)生輸送物之間的相互碰撞擠壓,使輸送物損壞,甚至崩落或損傷人、機。為了避免此類事故,所以需要設(shè)計一個阻尼裝置,即制動輥。
二、 設(shè)計內(nèi)容
根據(jù)重力滾道輸送機發(fā)展的需要,根據(jù)客戶的實際條件的需求,結(jié)合機械技術(shù),參考、計算、分析現(xiàn)有的重力滾道輸送機,設(shè)計出一套符合設(shè)計要求及社會需求的方案。
三、 設(shè)計方法及及技術(shù)路線
1、設(shè)計方法
(1)選擇設(shè)計題目,仔細聽取老師所講的內(nèi)容,認真思考一下。
(2)上網(wǎng) 、去圖書館查閱資料,弄明白自己到底需要做什么。
(3)根據(jù)所收集的資料作出設(shè)計方案。
(4)經(jīng)過計算設(shè)計的數(shù)據(jù),畫出設(shè)計裝配圖、零件圖。
(5)整理資料,寫設(shè)計說明書,準備答辯。
2、技術(shù)路線
我所設(shè)計的重力滾道輸送機阻尼裝置是一種制動輥裝置,它能根據(jù)輸送機的速度與給定的速度進行對比,然后進行有效的調(diào)整。
3、參考文獻
1.濮良貴、紀明剛主編?!稒C械設(shè)計(第八版)》。高等教育出版社
2.孫恒、陳作模、葛文杰主編?!稒C械原理(第七版)》。高等教育出版社
3.申綱領(lǐng)主編?!冬F(xiàn)代物流管理》。北京大學出版社
四、 設(shè)計安排
3月中旬:領(lǐng)取設(shè)計題目
3月中旬到4月初:查閱相關(guān)資料,初步提出設(shè)計方案
4月6日到10日:進行畢業(yè)實習
4月下旬:撰寫開題報告和實習報告,并提出設(shè)計方案
4月下旬到5月初:進行結(jié)構(gòu)方案設(shè)計,繪制裝配草圖
5月初到六月初:進行設(shè)計計算,對方案中涉及到的各零部件進行選擇并對其剛度、強度等進行核算,并繪制零件圖、裝配圖
6月上旬:整理、編寫任務說明書,并打印零件圖、裝配圖、任務說明書,準備畢業(yè)答辯
五、 設(shè)計總結(jié)
指導教師意見:
指導教師: 年 月 日
目 錄
摘要 …………………………………………………………………1
第1章 緒 論 1
1.1 現(xiàn)代重力輥道輸送機的概況 1
1.2 重力輥道輸送機阻尼裝置現(xiàn)狀...............................................................2
1.3 主要內(nèi)容及技術(shù)指標 4
第2章 總體方案的設(shè)計 6
2.1重力滾道輸送機阻尼裝置的工作原理 6
2.2方案的選擇 6
2.3主要工作部件的設(shè)計 7
第3章 總體配置的確定 8
3.1阻尼輥筒的整體設(shè)計 8
3.2傳動系統(tǒng)設(shè)計 8
3.3傳動裝置 9
3.4制動塊的設(shè)計 9
第4章 阻尼輥筒的整體設(shè)計 10
第5章 制動塊的設(shè)計......................................................................10
5.1制動塊的受力分析.............................................................................11
5.2計算摩擦快所受的擠壓力Fj............................................................11
5.3求離心力FL.......................................................................................11
5.4計算擺塊的有關(guān)參數(shù)........................................................................12
5.5計算阻尼輥筒內(nèi)部的傳動比i..........................................................13
第6章 傳動部分設(shè)計 14
6.1初定Vt、D2和i.......................................................................................14
6.2確定齒輪的模數(shù)和齒數(shù) 14
6.3確定輥子的其他結(jié)構(gòu)參數(shù) 15
第7章 內(nèi)置式阻尼輥筒的保養(yǎng)、使用、調(diào)整及修復 15
7.1每日技術(shù)保養(yǎng) 15
7.2傳動裝置的使用和調(diào)整 16
7.3阻尼輥筒的保管 16
7.4工作部件損壞的修復和調(diào)整 16
全文總結(jié)與展望 17
總結(jié) 17
課題展望 17
致謝 18
參考文獻 19
1
摘 要
重力式滾道輸送機因其不需動力,結(jié)構(gòu)簡單等優(yōu)點,在短距離物料輸送中得到廣泛的應用。重力式滾道輸送機是利用輸送物自身的重力沿斜面下滑進行輸送的。由于重力的作用,輸送物會愈滑愈快,產(chǎn)生輸送物之間的互相碰撞擠壓,使輸送物損壞,甚至崩落或損傷人、機。在輸送過程中,也可能由于輸送機自身的原因,如輥筒變形過大,貨物底部或托盤底部的粗糙或不規(guī)則,使其在輸送過程中停止不動,無法再起動重新下滑,這時需要人力協(xié)助推動恢復下滑。
為了達到設(shè)計要求,根據(jù)較普遍的重力式滾道輸送機,本設(shè)計阻尼裝置主要采用內(nèi)置裝置。這在很大程度上節(jié)省了人力,而且在結(jié)構(gòu)上比傳統(tǒng)設(shè)計方法更為合理。經(jīng)計算、校核,該裝置符合設(shè)計要求,適合作為重力輥道輸送機阻尼裝置。
關(guān)鍵詞:重力式滾道輸送機;阻尼裝置;
Abstract
Gravity groove conveyor because its does not need to power, simple structure, etc, and in short material conveying widely applied.Gravity groove conveyor belt conveyor is using its own gravity conveying things along the decline in transmission cant.Because the pull of gravity, conveying the slippery thing will soon, produce conveying the each other between things collision extruding, make things conveying damage, even caving man, machine or injury. In the course of transmission for, also may be due to the conveyor their own reasons, such as the rollers deformation is too large, the bottom tray or at the bottom of the rough or irregular, in the conveying process is at a standstill, can't start to decline, at this moment need to promote human help restore to slide.
In order to meet the design requirements, according to universal gravity groove conveyor, this design damping device is mainly using built-in device. This is largely save manpower, and on the structure more reasonable than the traditional design method.The calculation, checking, this device comply with the design requirements, suitable for as gravity roller conveyor damping device.
Key words: Gravity groove conveyor;Damping device。
III / 19
4 / 19
在工程設(shè)計研究13(2002)55±64
工業(yè)部10.1007 / s00163 - 001 -0007- 4
針對理想的機械工程設(shè)計支持系統(tǒng)的研究
大衛(wèi)G.Ullman
摘要:本文詳細介紹了在開發(fā)進展理想的機械設(shè)計的支持系統(tǒng)。它試圖填補這個工程師的需求和目前市面上的計算機輔助設(shè)計(CAD)系統(tǒng)之間的差距。自從強調(diào)了計算機輔助設(shè)計(CAD) 這個術(shù)語,電腦已成為人類設(shè)計師的強有力的助手,這篇文章的內(nèi)容是設(shè)計師的的中心任務。它緊緊根據(jù)設(shè)計師所做的項目和他們開發(fā)的信號系統(tǒng)項目的類型。17項關(guān)于理想機械設(shè)計的支持系統(tǒng)在這里被一一列舉出來。這些先進的信號系統(tǒng)直接應用于設(shè)計過程和實際應用與發(fā)展中,對于這十七項中的任何一項,根據(jù)目前他們的發(fā)展情況,他們是目前最先進也是有很大未來發(fā)展空間的研究項目。
關(guān)鍵詞:機械工程設(shè)計、計算機輔助設(shè)計(CAD),支持系統(tǒng)。
1
介紹
本文總結(jié)了理想機械工程設(shè)計支持系統(tǒng)的發(fā)展進程。近30年來,計算機輔助設(shè)計系統(tǒng)已經(jīng)被他們的開發(fā)者作為支持系統(tǒng)工程設(shè)計,發(fā)展產(chǎn)品的系統(tǒng)加以吹捧。這是說計算機輔助設(shè)計(CAD)系統(tǒng)在關(guān)于怎樣在工作場所使設(shè)計得以實現(xiàn)方面有重大的影響…,令人驚訝的是,很少有關(guān)于這個系統(tǒng)的對設(shè)計者和最終產(chǎn)品方面影響的正式研究。這篇文章介紹了一種討論這些效應結(jié)構(gòu)。
2000年2月11日收到:/2000年12月9日校稿:
2001年9月19日接受: /2001年11月13在線發(fā)表
2001年Springer-Verlag
D.G.Ullman
俄勒岡州立大學機械設(shè)計方面的榮譽退休教授,機械工程研究所碩士論文。具有較強的權(quán)威性性公司的董事長,Corvallis大街800號,美國俄勒岡州97330。
電子郵件:ullman@robustdecisions.com:
本文由Autodesk資助;但是, 聲明這些意見和結(jié)論的作者主要是基于他的工作。
最近,并被認為是徹底的,全身心投入此項尖端研究的學者只有八個,他們大多集中在二維 [1,15,17,18,22,23,24,25]。作者沒有發(fā)現(xiàn)他們關(guān)于影響參數(shù)系統(tǒng)的研究性文章被出版。
在這樣做的同時,他們總結(jié)了目前已知的和需要的研究東西。最后,探討了計算機輔助設(shè)計(CAD)系統(tǒng)發(fā)展來支持增加用于開發(fā)的產(chǎn)品活動部分。
這個學期的計算機輔助設(shè)計(CAD)強調(diào)計算機對于人類的設(shè)計師是一種援助,所以本文的主旨是中心設(shè)計者。它是根據(jù)這個活動緊緊依賴這個活動的設(shè)計師和他們開發(fā)的信息系統(tǒng)執(zhí)行。在許多方面,這是以前發(fā)表的兩個文件的一個更新(“繪制圖紙在機械設(shè)計過程中的重要性”和“設(shè)計的發(fā)展史存在的問題、設(shè)計合理性以及設(shè)計意向系統(tǒng)”)。 最近的一些文章提出13個突出的問題需要解決去實現(xiàn)并且提出了一種去改進設(shè)計過程和有此引起的設(shè)計信息潛在的工程設(shè)計的疑問。
這第一筆由基金會出資進行研究研究的論文是有五個具有不同的背景和經(jīng)驗的機械設(shè)計工程師發(fā)表的。他們每個人都會給于關(guān)于其中一兩項的詳細說明書,但是實際的機械設(shè)計中的問題的還是在現(xiàn)實的實踐中遇到。當工程師們正著手于解決問題時,他們被強烈的要求去思考解決辦法。他們的口頭報告,圖紙,手勢被錄像和錄音大約能夠持續(xù)6到10 小時。根據(jù)被謄寫的這些錄音資料數(shù)據(jù)獲得一個關(guān)于這次設(shè)計會議的草案。每一個設(shè)計者都在他們解決問題的方法中繪制了幾張圖紙加以說明。所有的這些都是在圖紙上。計算機輔助設(shè)計(CAD)系統(tǒng)沒有被用于研究,因為沒有設(shè)計者在他們的日常設(shè)計中使用計算機輔助設(shè)計(CAD)它的使用對一個已經(jīng)復雜的實驗來說會增加勞動強度。
根據(jù)長達40多個小時的數(shù)據(jù)顯示,15節(jié)關(guān)于每門科目的概念、布局、詳細的典型設(shè)計被精選出來。這個草擬數(shù)據(jù)中其中的15個章節(jié)涵蓋了這些數(shù)據(jù)的174數(shù)據(jù)單元。通過總結(jié)分析觀測結(jié)果得出結(jié)論繪制成圖紙并將將之運用于以下幾個方面:
1、檔案的幾何形態(tài)設(shè)計的
2、設(shè)計師之間和設(shè)計師和生產(chǎn)人員之間的思想交流
3、作為一種分析工具,通常, 不確定的尺寸和圖上的公差進行開發(fā)
4、模擬的設(shè)計
5、作為一個完整性檢查者,作為草圖或者其他正在繪制中的圖紙剩下的設(shè)計細節(jié),這些對于設(shè)計師來說變得清晰。實際上,幫助建立一個完成剩下設(shè)計任務的議程
6、作為一個設(shè)計師的短期記憶的延伸。設(shè)計師往往無意識地使用草圖幫助他們記得的他們可能忘記的想法。
1990年的圖紙再次被發(fā)現(xiàn)并且是支持證明這些這個說法。此外,雖然受試者不使用計算機輔助設(shè)計(CAD)系統(tǒng),但是結(jié)果卻表明:
1、計算機輔助設(shè)計(CAD)系統(tǒng)必須允許草圖的輸入。
2、計算機輔助設(shè)計(CAD)系統(tǒng)必須考慮到設(shè)計師使用的多種的接口界面。這雖然不意味著更多的方法去定義一個交際圈,但是必須去尋找一個滿足設(shè)計者需求的接口與計算機輔助設(shè)計(CAD)上的圖像相交流。
3、計算機輔助設(shè)計(CAD)必須能夠識別域相關(guān)的因素及完成他們的實體。
4、CAD工具需要能夠管理約束(甚至)摘要和功能的限制)并且確保他們的滿意,因為這是明顯的,人類的設(shè)計師在對他的認知能力是有限。因此這篇文章表明,計算機輔助設(shè)計(CAD)系統(tǒng)已經(jīng)成熟了并指出,至少在某種程度上有以上四種結(jié)論。然而,即使最新的系統(tǒng)是和理想的機械工程設(shè)計支持系統(tǒng)之間仍有很大的差距。這篇文章對最理想的系統(tǒng)被描述并對對其進展進行了討論。
2
一個模型設(shè)計問題的解決
對設(shè)計者來說或許在將來的某天能夠戴上承載他(她)們理想和發(fā)展一種硬件陳述的“理想的帽子”。關(guān)于認知過程、計算機輔助設(shè)計(CAD),和快速成型的研究正在它的領(lǐng)域進行。這種現(xiàn)狀意味這我們可以在我們頭上陳述足夠好的可擔保的硬件將被開發(fā)出的概念。我們還可以假想計算機輔助設(shè)計(CAD)系統(tǒng)已經(jīng)足夠先進,能夠很好的承載我們的想法和處理好零件和總體的發(fā)展變化。計算機輔助設(shè)計(CAD)系統(tǒng)的發(fā)展需要的到設(shè)計者認知工作的理解。只有這樣想法設(shè)想和表達陳述直接的互通才有可能。
所以去探究關(guān)于這個環(huán)節(jié)已知的知識,考慮人類問題的解決者和用數(shù)字表示的外部環(huán)境直接的關(guān)系是非常重要的。這組數(shù)據(jù)是基于紐厄爾和西蒙對模型的研究并被稱為數(shù)字處理信息系統(tǒng)(IPS)。這些數(shù)據(jù)圖表是關(guān)于設(shè)計信息的產(chǎn)生和儲存的一個簡單的“地圖”。這些圖標同時也展示了一個內(nèi)部的,人類解決問題的環(huán)境(設(shè)計者的內(nèi)心)和外部環(huán)境(設(shè)計者思想外的客觀環(huán)境)。對于設(shè)計師來說,兩個位置對應的是兩種不同類型的記憶:短期記憶(STM)和長期記憶(LTM)。設(shè)計師外部的記憶方法有很多,有許多“設(shè)計存儲地點”包括圖形表示法、媒體例如:紙張和CAD工具,以及其它媒體,如:文本筆記、手冊和各位同仁。每種記憶方式都有它運用于實際設(shè)計場合的背景和方法。短期記憶(STM)和長期記憶(LTM)特征細節(jié)是基于紐尼爾和西門的思維模型。 它的延伸已經(jīng)被制成視覺圖片以及他的影響已被編碼。人們必須認識到這個模型在這所包含的內(nèi)容雖然不完全同意認知心理學,但是他們足夠安全提供為討論CAD在機械設(shè)計中的作用討論依據(jù)。
2.1
短期記憶
短期記憶是非常快并且強大的。短期記憶的內(nèi)容是我們意識到信息,也就是說,我們的有意識的心智。所有的設(shè)計操作(例如,視覺感知和圖紙創(chuàng)作)是基于短期記憶(STM)的信息。不幸的是,STM容量能力有限。研究表明,它是限于大約七個認知單位或者大量的信息。在設(shè)計中,這些碎片是視覺圖像信息的形式能信息、事宜的心理模式以及在CAD中表示想法的步驟,或者其他離散的信息碎片。雖然短期記憶的容量的有限,但它是一種處理時間僅是100毫秒的快速處理器。
2.2
長期記憶
另一方面,長期記憶有本質(zhì)上的無限容量,但是進入長期記憶的通路也慢了。進入長期記憶的通道也不是直接的。記憶也必須是一些提示或是基于短期記憶的信息檢索策略引發(fā)。在設(shè)計中,有一部分內(nèi)容被儲存在長期記憶中。那些有相對比較簡單的線索供引發(fā)記憶,因為,在任何時候,目前重要的設(shè)計部分都是在STM中并能充當長期記憶中的知識思想的指針。
23
外部環(huán)境,
在這個試驗(1990年)中,很明顯許多繪畫行為不習慣于用文字記載設(shè)計過程中的結(jié)果。
但是繪制本省就是設(shè)計活動的一部分。如果這個畫表可以將他們所做的這些呈現(xiàn)在他們腦海中,他們就可以按他們腦海中呈現(xiàn)的這樣做而不用做草圖,筆記和在紙上計算。因此,我們可以得出的外部環(huán)境常被用作長期記憶和短期記憶的延伸。在外部環(huán)境中運用媒體來提高設(shè)計者的認識能力是至關(guān)重要的。區(qū)分開媒體和人類的認知之間的關(guān)系密不密切是這篇文章的一個目標。本文所采用的方法首先是描述信息處理的類型,然后討論設(shè)計師由外部環(huán)境影響所作出的舉動。這些信息的類型和舉動對于理想的系統(tǒng)能力來說是成熟的。每節(jié)以最理想的工程設(shè)計支持系統(tǒng)應該具有怎樣的功能為內(nèi)容開始。其余次要的信息遵循這些內(nèi)容.其次是關(guān)于記事本、二維CAD系統(tǒng),固體模型系統(tǒng)、參數(shù)系統(tǒng),以及其他支持工具怎樣滿足理想要求的描述。這樣使各分部得到改進的機會。
Toward the ideal mechanical engineering design support system
David G.Ullman
Abstract This paper details the progress toward the development oftheidealmechanical engineering design support system.It attempts to look at the gap between the needs of a mechanicalengineerandwhatis currently available onCAD systems Since the tern:CAD emphasizes that the computer is an aid to the human designer,this paper is designer centric it is based heavi~on the activities performed by designers and the types ofinformation developed by then:Seventeen goals for the ideal mechanical design support system are listed These are directed at the types ofinfor mation developed during the design process and the activ ities used to develop them For each of the seventeen,background information,the current state of the art,and opportunities for future development are itemized
Keywords Mechanical engineering design,CAD,Support system
1
Introduction
This paper summarizes the progress made toward the development of the ideal mechanical engineering design support system For nearly 30 years,computer aided de sign(CAD)systems have been touted by their developers as systems that support engineering designers developing products CAD systems have had a major impact on how design is accomplished in the workplace This being said,there is amazingly little ibrmal research on the effects of these systems on the designers and on the final products’This paper presents a structure for discussing these effects
In doing so、lt summarizes what is known and what needs co be studied Finally、it discusses how CAD systems have evoh,edto supportincreasingportions ofthe activitiesthat are used to develop products.
The term CAD emphasizes that the computer ls an aid to the human designer,so this paper is designer centric it is based heavily on the activities pertbrmed by designers and the types ofintbrmation developed by them in many ways,this is an update of two earlier papers,‘‘The importance of drawing in the mechanical design process”[29 J and“issues critical to the development of design history,design ratio nale and design intent systems”【311 The latter paper developed 13 outstanding issues that needed to be resolvedto realize the capture and query ofengineering design intormation as a potential lor lmprovmg the design process
and the reuse ofdesign Intormation.
The tbundation for the first paper was the study of the marks made on paper by nve mechanical design engineers of varying backgrounds and experience They were each given the initial specifications tbr one of two t~irly simple, yet realistic,mechanical design problems taken from professional practice The engineers were requested to think aloud as they soh,ed the problems Their verbal reports、drawings,and gestures were video and audio taped for aperiod of6 10 h The taped data were then transcribed to obtain a‘‘protocol”of the design session Each designer made numerous drawings during his or her solution of the problem A11 0fthesewere on paper CAD systemswere not usedinthe studgbecausenone ofthedesigners usedCADln their daily practice,and its use would have added another variable to an already complex experiment.
From the more than 40 h ofdata taken,15 sections were selected that represented typical conceptual,layout,detail and selection design for each subject The 15 sections of protocol data consisted of 174 rain of data The data were analyzed to explore the observations that drawings are
usedto:
1 Archive the geometric torm of the design
2 Communicate ldeas between designers and between the designers and manufacturing personnel
3 Act as an analysis tool Often,missing dimensions and tolerances are calculated on the drawing as it ls developed
4 Simulate the design
5 Serve as a completeness checker As sketches or other drawings are being made,the details left to be designed become apparent to the designer This,in ett)ct,helps establish an agenda of design tasks leL to accomplish
6 Act as an extension of the designer’s short term memory Designers often unconsciouslv make sketches to help them remember ldeas that they might otherwise torget
The 1990 paper refined and supported these observa tions AdditionalIv,although the subiects did not use CAD systems,the resuhs suggested that:
1 CAD systerns nl[ist allow tbr sketching lnput
2 CAD systerns nlust allow for a variety of Interfaces tbr the designer This does not mean more ways to define a circle、but an eftort to match the interface and the im age on the CAD system to that needed by the designer
3 CAD systems iiltlSt recognize domain dependent features and treat them as entities
4 CAD tools need to be able to manage constraints(even abstract and tkmctional constraints)and ensure their satistaction、as it is evident that human designers are cognitively limited in this ability
Since that paper was written,CAD systerns have matured and have addressed、at least to some degree、all南ur of the conclusions iIowever,even the most recent systems are a ong way tbom the ideal mechanical engineering design support system In this paper,the ideal system will be described and progress toward this ldeal discussed
2
A model of design problem solving
it may someday be possible for a designer to put on a ‘‘thinking cap”that can take his or her thoughts and de elop a hardware reDresen【atlon Research on under standing cognitive processes,CAD,and rapid prototyping ls certainly moving ln that direction This ideal implies that we can tbrmtflate concepts Jn our heads that are sumciently well tormed to warrant hardware It also as sumes that CAD systems are suflicientlg developed to take our thoughts and manage the evolution of parts and as semblies CAD system development will require an tin derstanding of the cognitive workings of designers so that the transition tbom thought to representation is possible
To explore what ls known about this link、consider the relationship between the human problem soh,er and the external environment shown in Fig 1 This figure ls based on the model developed bv Newell and Simon『20l and ls called the information processing system(IPS)The figure is a simple‘‘map’’ofwhere information about the design is developed and stored The figure shows an internal,human problem solving environment(inside the mind of the designer)and an external environment(outside the mind of the designer)Within the designer,two locations correspond to the two different kinds of memory:short term memory(STM)and long term memory(LTM) External to the designer,there are many‘‘design storage locations”including graphical representation media such as pieces of paper and CAD tools,as well as other media such as textual notes,handbooks,and colleagues Each location has certain properties that affect how it can be
used in design
Detail on the charac Leris【ics of the STM and the LTM ls based on Newell and Simon’s model[20 J Extensions have been made to it for visual imagery【1 l,12,13 J and efforts
have been made to codil~~it【21 it must be realized that the contents of the model given here are not folly agreed to in the cognitive psychology community,but the),are cer tainly secure enough to provide a basis for discussing the role of CAD in mechanical design
2.1
Short-term memory Short tern:memorg ls verv fast and powerful The contents of the STM are the information we are aware of,that is,our conscious mind All design operations(。g,visual perception and drawing creation)arebased oninformation in the STM Unfortunately,the STM has limited capacity Studies show that it is limited to approximately seven cognitive units or chunks of information During design, these chunks are visualimages offorn:s,information about fonction,mentaln:odels offit,stepsto represent anideain a CAD system,or other discrete pieces of information Although limited in capacity,the STM is a fast processor with processing times on the order of 100 nls[41
2.2
Long。term memory The long term memory,on the other hand,has essentially infinite capacity,but access is slow Access to LTM is also not direct Memories rntlSt be triggered by some cue or
retrieval strategy based on intbrmation in STM During design,parts of the design are stored in LTM These are relatively easy to cue because,at any time,currently in: portant parts of the design are in the STM and can act as pointers for the knowledge in the LTM
2.3
ExternaI environment
in the experiments run in 1990[291,it was clear that many drawing actions were not used to document the results of the design activity but were part of the design process itselg if the subjects could bare performed these activities in their heads they would have done so without making the sketches,notes,and calculations on paper Thus,it is concluded that the external environment ls often used as an extension of the STM and LTM it ls critical that the media used in this environment support the designer’s cognition Itemizing the match or mismatch between the media and human cognition is one of the objectives of this paper
The approach taken in this paper is to first describe the types ot'information managed(Sect 3)and then discuss the activities performed by the external environment support ing the designer(Sect 4)The types of information and activities are developed in terms of the capabilities of an ideal system Each subsection begins with statements about what the ideal engineering design support system should do Supporting information follows these statements Next, there is a description of how paper and pencil,2 D CAD systems,solid modeling systems,parametric systems,and other support tools meet the ideal Each subsection concludes with 0DD0r【unl Lles for lmprovement
3
Information managed by an ideal mechanical engineering design suppo~system
Mechanical engineers manage a broad range of informa tion in this section,the X arious types of information will be itemized,beginning with the most basic and progress ing to the most demanding
3.1
Form,fit,and fun~ion
The ideal engineering design support system should:
1 Allow designers to work I?om des£red Junction to the other types oj lnlornlation
2 Allow designers to flexibly work on the architecture, shape,^f,and function of parts and(zss0川blies
The mechanical design community has traditionally thought in terms of form,fit,and function Figure 2 shows the interplay among these basic types of information that describe the product being designed Generally,the reason for the obiect being designed is to fulfill some desired functions The form of the parts and assemblies,and the fit between them,depend on the desired function of the product Thus,the ideal system should allow the designer to work ffonl funotion to fornl and fit
The term‘‘form’’actually implies both the architecture and the shape of parts and assemblies(Fig 3)The term ‘a(chǎn)rchitecture’’has come to mean the skeletal structure that maps the function to the form Architecture is the‘‘stick figure”that can be easily manipulated and changed before the shape is refined Shape implies the geometry that adds hodV and detalt to tne arcnltecture utten deslgners i~l-st develop the general architecture of the object being de si~dned then add detaits about shape an(1 fit Where wP n憎today Engineers gener~dly work from the ftnlction of a systel~、to the architecture of an assembly,to the shape of parts iaunction occurs primarily at the con nections or fits between the parts ln an asselnbly ill other wor(1s mnction ls devdopetl ln assemb[ies lhis belng said,CAD systems have primali Ly supported the forln or geometry devetopnlent ot parts
Paper and penci[attm~s easy sketching of architecture with stick fi~ures and their evo[ution to conlponents Paper and pencil atso supports[imited function nlodeling through sketchinl4 actions that show lnotion or flow ln assemblies『9、14]
Both 2 D CA/3 systems and paper and pencil are fimited to simple input of line seglnents to represent the edges of COlnponents Solid naode[ing systelns are stilt Colnponent oriented even though they support the representation of edges,surfl~ces,and sotids Parametric systems gl eafly
lniprove(1 the lllode[illl4 of fornl with the Iimlted ability to modeI nt…d as…blles
Future systel~S need to help the designer visualize fllnction before geometry is fully defined Computer sys tenls are allowing better representation of fllnction,。g, kinelnatic,dynamic,fluid flow,and virtmd reality systems With the continued development 0f COlnputer support tools the ability to work fr0111 fllnction to form will …tlnl_e呲v0Lve
CA/3 systems to date have been part driven Parts are developed and then fittecl to~ether to make an assembly Ihe contributions oftheIayOtlt dlawinK have not beenwe[1 supported Paralnetric systems have begun to l~OVe to a nlore natural flow,but parametric nlode[ing requires the designer to PIan ahead of time the geometric constraint rekltionships that define the part,Mally parametric sys tells refer to the orderlng of the constraints as the design intent Ihis methodo[oD",while lnoving to~ard the ide~d, does not well support the designer as the p[allllillg needed adcls burden and the orderin~nlay not be known initi~flly and lnay change during the deve[oplnent Further,“design intent”as used ill parametric systems is too[imiting(see discusslon of deslfan Intent belowl
OpportunI Extend CAD systems to~d[ow the designer to develop the architecture of parts and assemb[ies to mliltl neede【l mnotion fhey nltlst atlow the designer to work fr0111 the architecture to the shaDe an(1 fit of the conlpo nents themselves lhis wi[1 require workinl4 wlth abstrac tions of parts an(1 asselnbIies as we[1 as buildlng the geometry of objects from their architecture and interfaces with other objects
3.2
Material and manufacturing
The ideal engineering design support system should: 3 Integratetheman@zcturing and assembl),practices and (oltlltl01,1 material usage oy the compan),or its vendors
One of the cornerstones of concurrent engineering is the integration of the development of the product and the processes that support the product Key among these processes are those used to manufacture the parts and assemble them These activities also depend on the selec tion or development of the best materials for the product Thus,as shown in Fig 4,the basic tbrm(architecture and shape),fit,and fonction need to be tied to materials,manufacturing,and assembly
Where we nre todi9,Currently、there are systems that aid in the development of injection molds and sheet metal parts flowever,for most manuthcturing and assembly methods,only text notes have supported this nongeo metric lnformation
OpportuMt),Extend CAD systems to provide the designer with intbrmation about anticipated material and manu
l;acturing methods This needs to be personalized as each
company and vendor has certain materials and manutac
turing and assembly methods that are standard and well
known Knowledge about these should be easily available
to the designer to aid in the development of parts and
assemblies
3.3
Cost
The ideal engineering design support system should:
4 Support the engineer so she or he is ctlv(~re。l the e‰ect
。f each Jblture change 01,1 costⅢit is generated
The cost to make the object being designed is not a part 0f its description,yet it is a major factor in all design considerations It is shown in Fig 5 as closely tied to the material used and the manufacturing method and through these indirectb to the ftinction and fornl Often there is a disconnection during the design process between drawing
what is being designed,but the limitations and targets on it As such,it is critical information As shown in Fig 6,there are requirements on at[the other types of infor mation previously discussed Traditionally,engineers have done a poor]ob at developing requirements tbr products Wher~w。(It6"tod~9,One of the best practices current[}, used to deve[op requirements in industry is quality func tion dep[oyment(QFD)[7,321 Many companies use the results of this method to direct[},feed requirements to the development of components and assemb[ies Admittedly, many of the requirements deve[oped with the QFD are for funotion;however,there are a[ways many constraints on both function and geometry that drive the development of parts and assemb[ies To date,this is not we[1 integrated
with CAD systems
Stauffer【26 J showed that as the design process n~oves from conceptual through[ayout to detail design,the source of constraints moves from those imposed from outside the control of the designer to those based on previous design decisions This imp[ies that not only shou[d requirements like those deve[oped using QFD type methods be integrated,but the reasoning behind earlier decisions also needs to be supported This wit[be further
discussed in the seclion on design intent fSect 3 61
Opportunity CAD systems need to integrate requirements and constraints into the deve[opment of parts and as semblies
3.5
Issues and plans
The ideal engineering design support system should:
6 Support the development,Jbllowing,and updating plans
7 Support the lmtrlagemenl issues not phtnned Jot.
Whereas at[the types of information described so ihr represent the artifacts being designed and the require ments on them,the lot[owing types of information repre sent the process through which the artifacts are developed
The importance of the process has been a concern ln in dustry since the earh 1980s and an area of research since the mid 1980s The tie between product and process is a maior part of concurrent engineering in the late 1990s, this concern became prominent with the development of interest in integrated product and process development (IPPD),the successor to concurrent engineering
Traditionally,the product design community addresses the design process ln terms of the tasks to be completed in dexeloping a new product These tasks are focused on specific design lssues that can be planned tbr in the de velopment of the product However、many issues arise duringthe design ofa productthat can notbe plannedtbr This ls especially true during the development of new
products or during the use of new technologies Figure 7 shows that lSStles and plans address all types of require merits and product information issues or tasks in product design require the designer to develop new lnformation 0ne of the first experiments aimed at unders【anding human Intbrmation processing during design tasks【27 J showed that over two thirds ofthe strategies used by the design engineers during the dexelopment of new products were searches through design space Searches imply that there is a range of potential sohltions to every issue and that the designer must look at several of these ahernative solutions to develop one that ls satisfactory Search strategies are well studied by the artificial intelligence community Three types of strategies defined by computer scientists and identified in the cognitive study were‘‘generate and test”, ‘‘generate and improve”、and‘‘means ends analysis”In each search type,the designer develops and refines the alternatives and compares them to the requirements until son2e satisfactory choice has been made ln the time vailable Based on these findings、in order to support designers,systems must not only track the completion of planned work,but must also support the development
and management of multiple ahernatives for all issues addressed
Where we nre todi9,Project planning and change n2an agement has always been a large part of engineering management Product data management(PDM)systems have made large strides toward integrating the actual de sign work with what was planned These systerns are still maturing
Opportunity Computer support tools need to continue to evoh,e to assist the engineer in developing the product and the process in an integrated fashion
3.6
Intent
The ideal engineering design support system should manage all the previously defined types ofinformat