3560 挖掘機工作裝置設(shè)計,挖掘機,工作,裝置,設(shè)計 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計（論文）中期檢查表指導(dǎo)教師： 范小彬 職稱： 副教授 所在院（系）： 機械與動力工程系 教研室（研究室）：機械工程教學(xué)部題 目 挖掘機工作裝置設(shè)計學(xué)生姓名 朱 坤 專業(yè)班級 08 機制四班 學(xué)號 0828050037一、選題質(zhì)量：（主要從以下四個方面填寫：1、選題是否符合專業(yè)培養(yǎng)目標(biāo)，能否體現(xiàn)綜合訓(xùn)練要求；2、題目難易程度；3、題目工作量；4、題目與生產(chǎn)、科研、經(jīng)濟、社會、文化及實驗室建設(shè)等實際的結(jié)合程度）挖掘機工作裝置設(shè)計這個題目很符合專業(yè)的培養(yǎng)目標(biāo)，能把書本上學(xué)到的理論 知識運用到實際生產(chǎn)中去，體現(xiàn)了綜合訓(xùn)練的要求，題目難易程度中等，題目工作量一般，能在規(guī)定的時間內(nèi)完成本次的畢業(yè)設(shè)計。本設(shè)計題目與現(xiàn)實生產(chǎn)結(jié)合很緊密，基本能投入社會生產(chǎn)實用。由于機械行業(yè)技術(shù)的快速發(fā)展，對現(xiàn)在的挖掘機性能提出了更新的要求，最主要做到低成本、高效率、高性能的產(chǎn)品，該題目以液壓動力為核心的綜合機構(gòu)，它與社會生產(chǎn)、科研、經(jīng)濟、社會、文化相關(guān)方面發(fā)展聯(lián)系非常緊密，結(jié)合程度高。二、開題報告完成情況：開題報告工作已經(jīng)完成，所需文獻(xiàn)資料已經(jīng)準(zhǔn)備齊全。三、階段性成果：1、進(jìn)行了資料的收集等前期準(zhǔn)備工作并完成了開題報告。2、基本模型已經(jīng)出爐。3、外國文獻(xiàn)的翻譯工作已完成。四、存在主要問題：1、無設(shè)計這方面結(jié)構(gòu)的經(jīng)驗，使得彎路多多，進(jìn)展緩慢。2、各生產(chǎn)廠家對各系列挖掘機的數(shù)據(jù)并沒有進(jìn)行公布，使得獲取實際數(shù)據(jù)困難。3、繪圖軟件使用生澀，影響了作業(yè)進(jìn)度。 五、指導(dǎo)教師對學(xué)生在畢業(yè)實習(xí)中，勞動、學(xué)習(xí)紀(jì)律及畢業(yè)設(shè)計（論文）進(jìn)展等方面的評語指導(dǎo)教師： （簽名）年 月 日河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 1 -外文翻譯原文出處 Submitted to ASME/JDSMC Special Issue on Sensors作 者 Jagannath Yammada, Terrence L. Chambers, Suren N. Dwivedi原文標(biāo)題 Intelligent Mold Design Tool For Plastic Injection Molding譯文標(biāo)題 注塑成型的智能模具設(shè)計工具摘要注塑成型是一個生產(chǎn)熱塑性塑料制品最流行的制造工藝，而模具設(shè)計是這個過程的一個重要方面。模具設(shè)計需要專業(yè)的知識、技能，最重要的是擁有該領(lǐng)域的經(jīng)驗。三者缺一不可。生產(chǎn)塑料組件需要選擇恰當(dāng)?shù)哪＞?，如果缺乏其中之一，這種選擇就得在反復(fù)試驗的基礎(chǔ)上進(jìn)行。這會增加生產(chǎn)成本，并造成設(shè)計上的不一致。本文介紹了智能模具設(shè)計工具的發(fā)展。該工具捕獲模具設(shè)計過程的知識，并且以符合邏輯的方式將這些知識反映出來。所獲得的知識將是確定性的，但模具設(shè)計過程中的信息是非確定的。一旦開發(fā)了模具設(shè)計工具，它將指導(dǎo)使用者根據(jù)不同客戶的要求，為其塑料零件選擇合適的模具。導(dǎo)言注塑成型工藝過程需要專業(yè)的知識、技能，最重要的是需要它成河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 2 -功的實踐經(jīng)驗。通常是工藝參數(shù)控制過程的效率。在制造過程中，有效地控制和優(yōu)化這些參數(shù)能實現(xiàn)一致性，這種一致性會在零件質(zhì)量和零件成本上表現(xiàn)出來的問題。1 智能化工程模塊注塑成型工藝（IKEM）基于知識的智能化工程模塊的注塑成型工藝（IKEM）是一種軟件技術(shù)，它領(lǐng)先于并行工程和 CAD / CAM 系統(tǒng)。它集成工程的設(shè)計和制造工藝的最新知識，給用戶各種設(shè)計方面的指示，通過減少在產(chǎn)品開發(fā)設(shè)計階段的工程變更，有助于減少一些工時。該系統(tǒng)將用于注塑設(shè)計，設(shè)計迭代和流程整合。目前的過程由許多手工計算、CAD 圖形結(jié)構(gòu)和從以前項目取得的經(jīng)驗三部分組成。一旦工程師完成設(shè)計，這將是性能評估。該 IKEM 項目已分為三大模塊。 (1) 費用估算模塊(2) 模具設(shè)計模塊(3) 生產(chǎn)模塊IKEM 系統(tǒng)有兩種形式輸入。在一個 CAD 模型的形式（Pro/E 文件）下輸入，和在給出的用戶界面形式下輸入。圖 1-1 說明了那種進(jìn)入每個模塊的輸入形式和用戶輸出形式。制造商的經(jīng)驗水平將決定如何有效地控制工藝參數(shù)。有時這就導(dǎo)致人為錯誤引起的不一致性。還有經(jīng)驗不足，時間、資源短缺和創(chuàng)新的空間不大的情況。通過創(chuàng)造所謂的“智能模型”的問題，工程學(xué)知識提供了一個可行的方案去解決所有這樣2 智能模具設(shè)計工具在它的基本形式中模具設(shè)計工具是一個從文本文件中提取輸入的Visual Basic 應(yīng)用程序，這種文本文件包含關(guān)于零件和用戶輸入程序。該文本文件包含來自 Pro/E 的一個信息文件的零件的幾何解析。輸入河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 3 -是用來估測模具得尺寸和其它各種特性。2.1 文獻(xiàn)回顧模具設(shè)計的是另一種注塑成型過程的階段，有經(jīng)驗的工程師在很大程度上有助于自動化進(jìn)程，提高其效率。這個問題需要注意的是深入研究設(shè)計模具的時間。通常情況下，當(dāng)設(shè)計工程師設(shè)計模具時，他們會參閱表格和標(biāo)準(zhǔn)手冊，這會消耗大量的時間。另外，在標(biāo)準(zhǔn)的CAD 軟件中需要大量的時間去考慮模具的建模組件。不同的研究人員已經(jīng)解決了縮短用不同的方式來設(shè)計模具所花費的時間的問題。凱爾奇和詹姆斯采用成組技術(shù)來減少模具設(shè)計時間。聚合一類注塑成型件的獨特的編碼系統(tǒng)和在注射模具中所需的工具已開發(fā)，它可以適用于其它產(chǎn)品生產(chǎn)線。實施編碼系統(tǒng)的軟件系統(tǒng)也已經(jīng)被開發(fā)。通過獲取在這方面領(lǐng)域的工程師的經(jīng)驗和知識，嘗試直接使模具設(shè)計過程的自動化。并行模具設(shè)計系統(tǒng)的研究開發(fā)就是這樣的一個過程，在并行工程環(huán)境中試圖制定一個系統(tǒng)的注塑模具設(shè)計流程。他們的研究目標(biāo)是研制一個有利于并行工程實踐的模具開發(fā)的進(jìn)程，和研制開發(fā)一個以知識為基礎(chǔ)的為注塑模具設(shè)計提供工藝問題和產(chǎn)品要求的輔助設(shè)計。通過各種方式獲取關(guān)于模具設(shè)計過程的確定信息和不確定信息，研究人員一直試圖使模具設(shè)計流程自動化。這個研究試圖研制開發(fā)一個獨特的模具設(shè)計應(yīng)用程序，它一確定性和不確定性兩種形式獲取信息。 2.2 采用的方法為了發(fā)展智能模具設(shè)計工具，傳統(tǒng)的模具設(shè)計方法在被研究。應(yīng)用程序開發(fā)人員和設(shè)計工程師合作設(shè)計一種特定塑料零件的模具。在此期間，被工程師采納用來選擇模底座的方法正在被地密切關(guān)注和篩選過程的各個方面，需要他的知識經(jīng)驗來確定。此外，有時候工程師將參考圖表和手冊以規(guī)范其甄選過程。這耗費時間的過程，稍后也被記錄在應(yīng)用程序中。河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 4 -系統(tǒng)的闡述依據(jù)輸入和輸出的應(yīng)用程序是下一階段。這涉及到如何定義什么養(yǎng)的模具布局信息是用戶最需要的，也是他輸入最少卻得到相同的輸出。根據(jù)在模具設(shè)計工作中收集到的信息，由工程師遵循的公約被轉(zhuǎn)化為 if - then 規(guī)則。決策表是用來解釋各種可能出現(xiàn)的情況，它們是當(dāng)處理模具設(shè)計工程中某一特定的方面所提出的。這樣被制定規(guī)則，然后被組織在相互交融的模塊中，使用應(yīng)用程序開發(fā)環(huán)境。最后，應(yīng)用程序是檢驗其正確性，當(dāng)涉及到為塑料零件設(shè)計模具在工業(yè)生產(chǎn)中。2.3 選擇合適的模架通常情況下，為制造塑料零件選擇適當(dāng)?shù)哪＜芩婕暗挠校海?）估計模腔數(shù) 模腔數(shù)量的決定取決于在一定時間內(nèi)所需部件的數(shù)量，像機器的塑化能力，廢品率等問題也會影響到模架的模腔數(shù)量。（2）確定鑲塊及其尺寸 鑲塊有助于模架重用，因此有助于降低生產(chǎn)成本。當(dāng)涉及到尺寸和數(shù)量的選擇，作出決定取決于現(xiàn)有的鑲塊的重用性和新的鑲塊的成本。（3）確定澆道的尺寸和定位 澆道的尺寸取決于所成型的材料。盡管還有其它要考慮材料特性來決定它的澆道的尺寸供符合它的流量要求。轉(zhuǎn)輪的定位，取決于所用流道的拓?fù)洳季?。雖然循環(huán)的澆道系統(tǒng)始終是最好的，支道系統(tǒng)的平衡，避免流道均衡補償?shù)臉渲顫驳老到y(tǒng)是一個最被廣泛應(yīng)用的系統(tǒng)。（4）確定澆道直徑 澆道直徑?jīng)Q定于模具的尺寸，模腔的數(shù)量或在一定的時間內(nèi)用來填補的塑料的總數(shù)。 （5）澆口的定位 塑料在某一點進(jìn)入模腔，在這點可以均勻填充滿模腔。澆口可以設(shè)在循環(huán)模腔的任何周圍點，但當(dāng)填補矩形腔時，必須從中部流進(jìn)。（6）確定供水道的的尺寸和定位 供水道之間和從模具中的任何壁上以標(biāo)準(zhǔn)的距離定位。該公約不是用一個直徑范圍定位水道在模具河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 5 -壁上。 （7）根據(jù)以上結(jié)論確定模具的尺寸 根據(jù)以上的所有結(jié)論，模具的大概尺寸可以被估計，并四舍五入至最接近的產(chǎn)品目錄號。在模架以前，如果重新設(shè)計，考慮到以上所有方面會降低成本和減少設(shè)計時間，進(jìn)入重新設(shè)計。2.4 問題的提出建立問題，需要人的知識和經(jīng)驗，模具設(shè)計方面消耗的時間涉及到圖表，數(shù)據(jù)表等，為開發(fā)應(yīng)用程序的問題解釋所示。雖然大部分的輸入如模腔數(shù)、腔的圖像尺寸、周期時間，都是根據(jù)客戶要求，其他輸入如塑化能力、每分鐘注射量等，可從機器的說明書中獲得。應(yīng)用程序的輸出包含模具尺寸和其他資料，這顯然有助于在目錄中選擇標(biāo)準(zhǔn)模架。除了輸入和輸出，圖 2 也顯示了產(chǎn)生的最終輸出的各種模塊。2.5 制定規(guī)則模具設(shè)計模塊的組織如果材料=“縮醛”和分流道長度“0，那么分流道直徑 = 0.062 結(jié)束當(dāng)制定了規(guī)則，重要的是我們用一種嚴(yán)謹(jǐn)?shù)姆绞降膩肀憩F(xiàn)這些信息，同時要避免重復(fù)、不完整和不一致的現(xiàn)象。決策表可以幫助處理上述問題，它是通過對過于冗余和廣泛的問題陳述的檢查實現(xiàn)的。比如說，在選擇適當(dāng)?shù)哪＜艿倪^程中，模架尺寸取決于型腔和鑲件的數(shù)目。為確情況 A:模具寬度 =(鑲塊長度 + 2)；模具長度=(鑲塊長度 + 2)；模具厚度=鑲塊厚度。情況 B:模具寬度=(2*鑲塊寬度 + 3.5)；模具長度=(鑲塊長度 + 2)；模具厚度=鑲塊厚度。情況 C: 模具寬度=(2*鑲塊寬度 + 3.5)；模具長度=(鑲塊長度 + 3)；模具河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 6 -厚度=鑲塊厚度。型腔的數(shù)目是一個，鑲件的數(shù)目也是一個的情況和型腔數(shù)目是兩個和四個的情況具有相同的模具尺寸，這三種情況可以歸結(jié)為一個單一的規(guī)則： 如果 鑲塊的數(shù)目= 1，則模具寬度 =（鑲塊寬度 + 2）模具長度 =（鑲塊長度+ 2）模具厚度 = 鑲塊厚度 結(jié)束為了方便和清楚起見，用一種標(biāo)準(zhǔn)的編程語言將這些規(guī)則模塊化。每個模塊生成一組輸出，這個輸出又將是對其他模塊的輸入。2.6 測試應(yīng)用通過使用各種測試案例對智能模具設(shè)計中的應(yīng)用程序進(jìn)行了驗證。對于每一個案件的零件信息，模具和機器的信息資料種類繁多，人類專家證實了把這些信息輸入到應(yīng)用程序的結(jié)果。表 2 顯示了一個這樣的試驗，需要兩個模腔，也沒有鑲件的存在。應(yīng)用程序提供近似的模具尺寸，執(zhí)行尺寸，澆口尺寸和亞軍的模腔長度基于模腔圖尺寸和其他信息。通過使用各種測試案例對智能模具設(shè)計中的應(yīng)用程序進(jìn)行了驗證。對于每一個案件的零件信息，模具和機器的信息資料種類繁多，人類專家證實了把這些信息輸入到應(yīng)用程序的結(jié)果。表 2 顯示了一個這樣的試驗，需要兩個模腔，也沒有鑲件的存在。應(yīng)用程序提供近似的模具尺寸，執(zhí)行尺寸，澆口尺寸和亞軍的模腔長度基于模腔圖尺寸和其他信息。獲得的模具尺寸非常接近人類專家的一個典型設(shè)計，但并沒有明確地說明了一個模具標(biāo)準(zhǔn)件的用途，就像 D-M-E 模具目錄中的一種特定的模具。模具尺寸是基于所用材料而定的，因此它被限制在一定的范圍。河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 7 -3 總結(jié)本文介紹了在發(fā)展智能模具設(shè)計應(yīng)用中所采用的方法，這種應(yīng)用是根據(jù)用戶輸入進(jìn)行模架選擇的。獲取知識的過程首先是通過與業(yè)內(nèi)專家密切協(xié)商設(shè)計一種模架，也通過從舊書和數(shù)據(jù)表中收集確定性信息。收集到的資料，表示了在不同的模塊中規(guī)則的排列形式。這些資料可定性和定量地對模具進(jìn)行選擇。決策表是用來減少規(guī)則庫的規(guī)模，使規(guī)則庫中的問題域全面。在不同的模塊中使用這些規(guī)則來開發(fā)應(yīng)用程序，當(dāng)談到在給業(yè)內(nèi)生產(chǎn)的塑件選擇適當(dāng)?shù)哪＜軙r就為應(yīng)用程序的有效性作測試。參考文獻(xiàn)[1] 錢伯斯 T. L.帕金森 A. R. “知識代表及專家系統(tǒng)的混合轉(zhuǎn)換。 ” 美國機械工程師學(xué)會，1998，120:468-474.[2] 凱爾其·詹姆斯 R.“軟件升壓模具設(shè)計效率”的成型系統(tǒng)，1999， 3:16-23. [3] 李榮顯，陳育民，鄒昶,“開發(fā)一個并行模具設(shè)計系統(tǒng)：以知識為基礎(chǔ)的辦法” ，計算機集成制造系統(tǒng)，1997，4:287-307. [4] 斯特德曼薩利 ·佩爾 M,“在工程設(shè)計專家系統(tǒng)：一種注塑成型的塑料件的應(yīng)用”智能制造，發(fā)動機 1995，2:347-353.[5] 費爾南德斯 A，卡斯塔尼 J,賽爾 F, “CAD / CAE 信息的模具和熱塑性塑料注射原型設(shè)計的”信息技術(shù) 1997:117-124. [6] 道格拉斯 M 布萊斯,“塑料注射成型，材料選擇和產(chǎn)品設(shè)計”1997:1-48.[7] 道格拉斯 M 布萊斯， “塑料注射成型模具設(shè)計基礎(chǔ)” ，1997，2:1-120. 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 8 -Session VA4Intelligent Mold Design Tool For Plastic Injection MoldingJagannath Yammada, Terrence L. Chambers, Suren N. DwivediDepartment of Mechanical EngineeringUniversity of Louisiana at LafayetteAbstractPlastic Injection molding is one of the most popular manufacturing processes for making thermoplastic products, and mold design is a key aspect of the process. Design of molds requires knowledge, expertise and most importantly experience in the field. When one of these is lacking, selection of an appropriate mold for manufacturing a plastic component is done on a trial-and-error basis. This increases the cost of production and introduces inconsistencies in the design.This paper describes the development of an intelligent mold design tool. The tool captures knowledge about the mold design process and represents the knowledge in logical fashion. The knowledge acquired will be 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 9 -deterministic and non-deterministic information about the mold design process. Once developed the mold design tool will guide the user in selecting an appropriate mold for his plastic part based on various client specifications.IntroductionThe plastic injection molding process demands knowledge, expertise and, most important, experience for its successful implementation. Often it is the molding parameters that control the efficiency of the process. Effectively controlling and optimizing these parameters during the manufacturing process can achieve consistency, which takes the form of part quality and part cost.The level of experience of the manufacturer(s) determines how effectively the process parameters are controlled. This sometimes leads to inconsistency introduced by human error. There is also the case where there is inexperience, shortage of time, resources and little scope for innovation. Knowledge-based engineering provides a feasible solution to all these problems by creating what is called an “intelligent model” of the problem.1 IKEMIntelligent Knowledge based Engineering modules for the plastic injection molding process (IKEM) is a software technology that is a step 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 10 -ahead of the concurrent engineering and CAD/CAM systems. It integrates current knowledge about the design and manufacturing processes and helps to reduce several man-hours by reducing engineering changes in the design phase of product development by giving users instruction about various design aspects. The system will be used for injection molding design, design iterations, and process integration. The current process consists of many manual computations, CAD graphical constructions, and experience attained from previous projects. Once the engineer completes the design, it will be evaluated for performance. The IKEM project has been divided into three major modules.1. The cost estimation module2. The mold design module3. The Manufacturing moduleInput to the IKEM system is of two forms. Input in the form of a CAD model (Pro-E file) and input given at the User Interface form. Figure 1 illustrates the kind of input that goes into each module and the output given to the user. Figure 1. Organization of the IKEM Project2 Intelligent Mold Design ToolThe mold design tool in its basic form is a Visual Basic application taking input from a text file that contains information about the part and a User Input form. The text file contains information about the part geometry parsed from a Pro/E information file. The input is used to estimate the dimensions of mold and various other features.2.1 Literature Review Design of molds is another stage of the injection molding process where the experience of an engineer largely helps automate the process and increase its efficiency. The issue that needs attention is the time that goes 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 11 -into designing the molds. Often, design engineers refer to tables and standard handbooks while designing a mold, which consumes lot of time. Also, a great deal of time goes into modeling components of the mold in standard CAD software. Different researchers have dealt with the issue of reducing the time it takes to design the mold in different ways. Koelsch and James have employed group technology techniques to reduce the mold design time. A unique coding system that groups a class of injection molded parts, and the tooling required ininjection molding is developed which is general and can be applied to other product lines. A software system to implement the coding system has also been developed. Attempts were also directed towards the automation of the mold design process by capturing experience and knowledge of engineers in the field. The development of a concurrent mold design system is one such approach that attempts to develop a systematic methodology for injection mold design processes in a concurrent engineering environment. The objective of their research was to develop a mold development process that facilitates concurrent engineering-based practice, and to develop a knowledge-based design aid for injection molding mold design that accommodates manufacturability concerns, as well as product requirements.Researchers have been trying to automate the mold design process either by capturing only the deterministic information on the mold design process or the non-deterministic information, in various ways. This research uniquely attempts to develop a mold design application that captures information in both forms; deterministic and non-deterministic.2.2 Approach AdoptedIn order to develop an intelligent mold design tool, the conventional method of designing molds is studied. The application developer and the design engineer work together in designing a mold for a particular plastic part. During this time, the approach adopted by the engineer to select the 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 12 -mold base is closely observed and aspects of the selection process that require his knowledge/experience are identified. Also, there will be times when the engineer will refer to tables and handbooks in order to standardize his selection process. This time consuming process is also recorded to incorporate it later in the application.Formulating the problem for the application in terms of inputs and outputs is the next stage. This involves defining what information about the mold layout is most required for the user and also the minimum number of inputs that can be taken from him to give those outputs.Based on the information gathered in the mold design exercise, the conventions followed by the engineer are transformed into if-then rules. Decision tables are used to account for all possible cases that arise when dealing with a particular aspect of the mold design process. The rules so framed are then organized into modules interacting with each other, using an application development environment. Finally the application is tested for its validity when it comes to designing molds for plastic parts manufactured in the industry.2.3 Selection of Appropriate Mold Base Typically, selection of appropriate mold base for manufacturing a plastic part involvesEstimating the number of cavities The number of cavities is decided depending on the number of parts required within a given time. There are also other issues like the plasticizing capacity of the machine, reject rate etc that affect the number of cavities to be present in the mold base.Deciding on the presence of inserts and their dimensionsInserts facilitate the reusability of the mold base and therefore help in reducing cost of manufacturing. When it comes to selecting the dimensions and the number, a decision is made depending on the reusability of existing 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 13 -old inserts and cost of ordering new ones.Determining the size and location of runnersThe runner size depends on the material being molded. Although there are other considerations material properties determines the channel size required for its flow. Location of runners mainly depends on the topology of runners being used. Though a circular runner system is always preferable, the branched runner system that avoids runner balancing is the one most widely used.Determining the diameter of sprueThe diameter of the sprue is decided based on the size of the mold, number of cavities, or the amount of plastic that is to be filled within a given time.Locating gatesPlastic enters the cavity at a point where it can uniformly fill the cavity. A gate can be located at any point on the perimeter of a circular cavity but has to enter at the midsection when it comes to filling rectangular cavities.Determining the size and location of water lines Water lines are located at standard distances form each other and from any wall in the mold. The convention is not to locate a waterline within one diameter range on the mold wall.Deciding mold dimensions based on above conclusions河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 14 -Based on all the above decisions the approximate mold dimensions can be estimated and rounded off to the nearest catalog number. Considering all the above aspects before even modeling the mold base reduces the cost and time that go into redesigning.2.4 Formulation of the ProblemBased on issues that require human knowledge/experience, and aspects of mold designthat consume time referring to tables, data sheets etc., the problem for developing theWhile most of the input, like the number of cavities, cavity image dimensions, cycle time are based on the client specifications, other input like the plasticizing capacity, shots per minute etc., can be obtained from the machine specifications. The output of the application contains mold dimensions and other information, which clearly helps in selecting the standard mold base from catalogs. Apart from the input and output, the Figure 2 also shows the various modules that produce the final output.2.5 Framing rules At this stage, the expert’s knowledge is represented in the form of multiple If-Then statements. The rules may be representations of both qualitative and quantitative knowledge. By qualitative knowledge, we mean 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 15 -deterministic information about a problem that can be solved computationally. By qualitative we mean information that is not deterministic, but merely followed as a rule based on previous cases where the rule has worked. A typical rule is illustrated below: If Material = “Acetal” AndRunner Length 0 ThenRunner Diameter =0.062End IfWhen framing the rules it is important that we represent the information in a compact way while avoiding redundancy, incompleteness and inconsistency. Decision tables help take care of all the above concerns by checking for redundancy and comprehensive expression of the problem statement. As an example, in the process of selecting an appropriate mold base, the size of mold base depends on the number of cavities and inserts. To ensure that all possible combinations of cavities and inserts have been considered we use a decision table and subsequently use the decision table to frame rules. Figure 3. Mold Dimensions for various combinations of Inserts and CavitiesThe case where the number of cavities is one and the number of inserts is one has the same mold dimensions as the case where the number of cavities is two and four. The three cases can be reduced to one single rule:If Number Of Inserts=1 ThenMold Width = (Insert Width + 2)Mold Length = (Insert Length + 2)Mold Thickness = Insert ThicknessEnd IfThe rules are arranged in modular fashion using a standard programming language for the sake of convenience and clarity. Each module generates a set of outputs, which would be inputs for other modules.2.6 Testing the applicationThe intelligent mold design application is validated using various test 河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 16 -cases. For each case the part information, mold information and the machine information are varied and a human expert validates the results of feeding this info into the application. Table 2 shows one such test case where the part requires two cavities and there are no inserts present.The application gives the approximate mold dimensions, runner dimension, sprue dimension and runner length based on the cavity image dimensions and other information.Table 2. Typical test case showing program input and output.The mold dimensions obtained are very close to a typical human expert design for the test case but do not suggest explicitly the use of a standard mold base, like a specific mold from the D-M-E mold base catalog. The mold dimensions are however useful in selecting appropriate mold base from the mold catalogs. The runner dimensions are based on the material being used and therefore are limited to a specific range of shot size.3 SummaryThis paper presents the approach adopted towards developing an intelligent mold design application that performs mold base selection based on user input. The knowledge acquisition process is done by first designing a mold base in close consultation with an industry expert and also by collecting deterministic information from hand books and data sheets. The collected information, which can be both qualitative and quantitative knowledge about the mold selection process, is represented in the form of rules arranged in different modules. Decision tables are used to reduce the size of rule base and make the rule base comprehensive in the problem domain. The application developed using the rules in different modules is then tested for its validity when it comes to selecting appropriate mold bases for plastic parts manufactured in the industryReferences河南理工大學(xué)萬方科技學(xué)院本科畢業(yè)設(shè)計- 17 -1. Chambers T. L., Parkinson A. R., 1998, “Knowledge Representation and Conversion of Hybrid Expert Systems.” Transactions of the ASME, v 120,pp 468-474 2. Koelsch, James R., 1999, “Software boosts mold design efficiency“ Molding Systems, v 57, n 3,p 16-23. 3. Lee, Rong-Shean, Chen, Yuh-Min, Lee, Chang-Zou,1997 “Development of a concurrent mold design system: A knowledge-based approach”, Computer Integrated Manufacturing Systems, v 10,n 4, p 287-307 4. Steadman Sally, Pell Kynric M, 1995, “ Expert systems in engineering design: An application forinjection molding of plastic parts“ Journal of Intelligent Manufacturing, v6, p 347-353.5. 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