腳盆注塑模具設(shè)計【含三維SW模型】【含CAD圖紙】

喜歡就充值下載吧，資源目錄下展示的全都有，下載后全都有，dwg格式的為CAD圖紙，有疑問咨詢QQ：414951605 或1304139763 基于Windows的三維塑料注塑模具設(shè)計系統(tǒng)摘要三維實體建模革命已經(jīng)是設(shè)計的主流。高端的三維實體造型系統(tǒng)已經(jīng)在工程師工作站，大型航空航天，消費電子產(chǎn)品，汽車企業(yè)里使用很多年，還有許多小公司，現(xiàn)在做著從工作站到PC 機的轉(zhuǎn)換。這樣做的原因之一是為了達到轉(zhuǎn)變靈活，并且基于Windows/NT平臺，軟件開發(fā)人員必須開發(fā)一種人們能負擔得起，而且易于使用的應(yīng)用程序。高端用戶發(fā)現(xiàn)，中程固體模型如SolidWorks，正符合他們的需求。SolidWorks被選定為用于處理Windows的設(shè)計環(huán)境平臺，它有強大的裝配能力，易與使用，學習快速，以及實惠的價格。Windows的本地三維塑料注射模具設(shè)計系統(tǒng)已被用于一種通過NT接口的Visual C + +代碼的商業(yè)軟件，SolidWorks 99和API 。該系統(tǒng)為設(shè)計師提供了一個互動式電腦輔助設(shè)計環(huán)境，這既可以加快模具設(shè)計過程，又可以促進其標準化。 關(guān)鍵詞：注塑模具; Windows; CAD; 零件1. 導言塑料零件被廣泛的使用在一系列大范圍生產(chǎn)中，從消費產(chǎn)品到機械，汽車和航空飛機，注塑過程已被確認作為一個重要的制造工藝。模具設(shè)計過程一般是一種新產(chǎn)品發(fā)展的關(guān)鍵。傳統(tǒng)上來看，模具設(shè)計一直是非?！澳涿睢钡乃囆g(shù)，在成為一個可以相對精通它的人之前需要積累多年的經(jīng)驗。由于最初學習這種藝術(shù)十分困難，所以越來越少的人能從在這領(lǐng)域有經(jīng)驗和知識的專家那里受益了。要改變目前的狀況，其中一種方法就是使用計算機輔助設(shè)計（ CAD ）系統(tǒng)。CAD作為日常術(shù)語已具有了非常廣的能力范圍，并已應(yīng)用到一系列領(lǐng)域，從作為學校教學的教具，到三維機械設(shè)計。目前，大多CAD系統(tǒng)只提供幾何造型功能，為草圖繪制模具設(shè)計減小困難，但并沒有為模具設(shè)計者提供必要的知識來設(shè)計鑄模。因此，許多“附加”的軟件，例如： IMOLD ，已被開發(fā)為高水平的3D建模平臺用來減輕模具設(shè)計過程的困難。這樣的安排在許多方面都是有利的。這種三維建模平臺提供了插入軟件與庫的功能，還有作為一個既定的用戶界面和風格的設(shè)計。其結(jié)果是，開發(fā)時間因為這些“附加”而大大減少。IMOLD （智能模具設(shè)計） 1 是一個基于知識下的，運行在綜合繪圖SolidWorks平臺下的應(yīng)用軟件，并實現(xiàn)了以使用用戶為條件的功能。它可用于Unix和Windows 操作系統(tǒng)。多年來，模具設(shè)計工程師必須處理兩個不同的系統(tǒng)，UNIX和PC。前者是廣泛應(yīng)用在工程中，而后者主要用于中小型企業(yè)。 工程師們還需要將它運行于企業(yè)中，例如辦公室中的文字處理，電子表格和項目管理工具，但這些并不是UNIX的工作范圍。幸運的是，隨著計算機技術(shù)的顯著發(fā)展，在過去十年中已提供了一種方法來改變這種狀況。最顯著的變化是在計算機硬件區(qū)域，即實際的電子部分與數(shù)據(jù)處理，信息存儲和顯示技術(shù)，速度和記憶兩方面。這些都使我們能更有效地利用固體建模功能在PC機的CAD / CAM 系統(tǒng)。隨著提供更多的先進低成本的軟件于Windows ，越來越多的工程師開始使用PC去完成他們的工作。因此，開發(fā)新的基于Windows平臺上的模具設(shè)計應(yīng)用軟件已經(jīng)有很高的需求。高端用戶發(fā)現(xiàn)，中程固體模型，如SolidWorks，正符合他們的需求。從開始作為一個本地的Windows應(yīng)用程序，如今SolidWorks已成為Windows下的一個3D機械設(shè)計軟件。其獨特的綜合生產(chǎn)水平，易用性和經(jīng)濟性是無與倫比的。SolidWorks 99，第七次公司主要發(fā)布的機械設(shè)計軟件用于Windows NT ，Windows 98和超越提供的平臺，它是將更多的功能集成于一個集成模塊的固體建模軟件。常用的，如點擊，拖放，剪切和粘貼，數(shù)據(jù)共享與其他導致其生產(chǎn)收益的Windows軟件。其易用性和廉價性可以在沒有廣泛進行培訓的公司使用并能夠安裝系統(tǒng)透射電鏡在每一個工程師的桌面上。它其中一個應(yīng)用是在模具設(shè)計中的塑料工業(yè)。這一最新的應(yīng)用程序技術(shù)為模具設(shè)計過程增添了一個全新的層面。2. 注塑模具設(shè)計注塑模具使用溫度依賴性變化的材料特性，通過使用鑄模以獲得最終形狀的零散部分完成或接近完成的產(chǎn)品。在這種類型的制造過程中，液體材料被用來填充和塑造內(nèi)腔造型 2 。首先，建立一個模型需要模具設(shè)計模型和載方塊。設(shè)計模型代表成品，而載方塊代表模具組件的總量。注塑模具設(shè)計涉及有關(guān)結(jié)構(gòu)和功的組成部分模具的廣泛經(jīng)驗知識（啟發(fā)式知識）。一個新的模具開發(fā)典型過程可分為四個主要階段：產(chǎn)品設(shè)計，模具的能力評估，細節(jié)零件設(shè)計，凸、凹模設(shè)計以及模具細節(jié)設(shè)計。最開始，一個產(chǎn)品的觀念是一些人齊心協(xié)力想出的（通常是結(jié)合營銷和工程）。開始的主要重點是分析市場機會和擬定合適的戰(zhàn)略。在第一階段，首先了解與進程相關(guān)的制造業(yè)的信息，然后設(shè)計制作詳細的幾何參數(shù)。設(shè)計的概念是轉(zhuǎn)化為采用適當?shù)纳a(chǎn)信息制造。第二階段在脫模方向和分型線的位置添加檢查模具的能力。否則，零件的形狀將被再次修改。第三階段，部分幾何參數(shù)是用來建立模具的型芯和型腔，以用于構(gòu)成零件。一般收縮和膨脹需要被考慮以便模具在高溫處理時形成正確的尺寸和形狀。澆道，氣孔也需要添加。將幾何數(shù)據(jù)和分型信息結(jié)合是至關(guān)重要的一點。第四階段涉及整體機械結(jié)構(gòu)的模具，包括注塑機的連接模具，一種用于填充，冷卻，排出和模具裝配的機構(gòu)。3. 方法論對于上述所有，SolidWorks 99已經(jīng)被作為該平臺的新模具設(shè)計投入應(yīng)用。圖1所示為Windows三維注塑模具設(shè)計系統(tǒng)與IMOLD的比較。用戶的應(yīng)用程序也可建立和運行作為一個獨立的exe.文件或用戶的DLL 或擴展DLL的SolidWorks。Solid Works的加載項管理器可以讓用戶在任何時候控制第三方軟件裝載在他們的SolidWorks上。一個軟件包不止加載一次，還可以設(shè)置停留在SolidWorks上。3.1. SolidWorksSolidWorks最近成為了基于Windows操作系統(tǒng)的三維產(chǎn)品設(shè)計軟件，它提供了一個最有力和直觀的一流機械設(shè)計解決方案。對于SolidWorks，零件的形成是通過建立一個“基本特征” 并增加其他功能，如主體，切割，打孔，框架等。該基本特征可能是一種擠壓，旋轉(zhuǎn)，彎曲配置，或高拋。要創(chuàng)建一個基礎(chǔ)特征，需要繪制一個二維幾何圖形并且移動圖形到空間中來創(chuàng)造一個容塊。幾何圖形可以被繪制在結(jié)構(gòu)平面或其表面部分。基于特征的固體建模程序被用于二維設(shè)計的方法雖然已經(jīng)過時，但由于基于Unix的固體建模軟件很昂貴，所以我們采用基于微軟Windows下的Solidworks ，它的成本價格低于之前的固體建模程序 3 。3.2 Parasolid作為三維內(nèi)核SolidWorks使用Parasolid作為一個三維內(nèi)核。 Parasolid內(nèi)核建模工具包，是公認的世界領(lǐng)先的，生產(chǎn)驗證的核心固體建模。設(shè)計上作為一種精確的邊界代表性建模工具，Parasolid提供強大的固體建模，廣泛的單元模型和集成面/層建模能力和被設(shè)計為簡單的一體化的CAD / CAM / CAE系統(tǒng)，加快了投放市場的時間。其大量的功能被作為庫的示例和面向?qū)ο蟮某绦蚪涌凇Ｋ鼘嵸|(zhì)上是一個穩(wěn)定的系統(tǒng)，可以用來 4 ：（一）建立和操縱固體物體; （二）計算質(zhì)量和轉(zhuǎn)動慣量，并進行干擾檢測;（三）用若干不同的表示方法輸出的物體; （四）存儲對象某種數(shù)據(jù)庫或存檔以及稍后的檢索;（五）支持自形成表面。3.3 API 5 SolidWorks的應(yīng)用編程接口（API）是一個對于SolidWorks的OLE編程接口。它包含數(shù)百個功能，可以被稱為Visual Basic,VBA（ Excel， Access等）,C ， C + + ，或SolidWorks的文件宏觀調(diào)控。這些功能提供編程直接訪問SolidWorks功能，如創(chuàng)建一條線，擠壓，或核實參數(shù)表面。API的界面采用了面向?qū)ο蟮姆椒?。全部該API函數(shù)的方法或?qū)傩?，適用于一對象。圖2是一個詳細的鑒于SolidWorks的應(yīng)用程序接口。SolidWorks的功能，通過公開的OLE自動化調(diào)度和使用派遣，也可通過標準的COM對象來進行。 調(diào)度接口 6 將打包不明確點并重新賦值為變量，這樣的語言如Basic便可以處理他們。COM執(zhí)行讓您應(yīng)用更多的可直接接觸的基本對象和其他的部分，提高其性能。4. 執(zhí)行實際上，SolidWorks API接口使用對象導向和API函數(shù)允許一個選擇的一種面向?qū)ο蟮恼Z言，例如：Visual C + +，作為的編程語言的方法。使用這種方法，應(yīng)基于Windows的三維注塑模具設(shè)計，應(yīng)用在Windows NT上通過接口的Visual C + +代碼的商業(yè)軟件， SolidWorks 99 。在此應(yīng)用程序的模具設(shè)計過程分為幾個階段，提供模具設(shè)計一致的方法去創(chuàng)建模具設(shè)計。這個概述框架的顯示如圖 3 。每一個階段可以被視為一個獨立的模塊的工程。這幾個模塊已被研制成功并使用在SolidWorks上。其中兩個，模具基礎(chǔ)模塊和顯示模塊如下。4.1 模具基礎(chǔ)模塊模具基礎(chǔ)模塊可以自動創(chuàng)建參數(shù)標準模具基地，以及其所有組成部分和配件，如HASCO ，DME， HOPPT ，LKM和FUTABA。該模塊可通過設(shè)計師輕松定制模具基地常用屬性。主要特點包括提供標準模具的基礎(chǔ)部件，例如支持支柱和澆道襯套， 2板和3板模具基地，和定制非標準模具基地。模具基礎(chǔ)模塊由四個主要部分組成，即組件庫（包括標準和非標準件庫），設(shè)計平臺，部分從動功能，結(jié)構(gòu)和連接管理。在這里，部分從動的功能提供了SolidWorks以支持該應(yīng)用程序。模具基礎(chǔ)模塊詳細顯示如圖 4 。（ 1 ）構(gòu)件庫在這個競爭日益激烈的世界，為了加強模具設(shè)計能力，降低設(shè)計成本和周期時間，減少人力， 自動化成為實現(xiàn)它的主要因素。換句話說，它必須有計算機軟件，這個可以輕松地創(chuàng)建，修改和分析模具的設(shè)計組件，并更新變化設(shè)計模型。為了實現(xiàn)這一目標，必須提供一個三維構(gòu)件庫用來儲存標準和非標準零部件數(shù)據(jù)，其尺寸都存儲在Microsoft Excel中。指定適當?shù)某叽纾@些構(gòu)件便可以生成并插入裝配結(jié)構(gòu)。這個庫是完全可定制的并且設(shè)計師能夠增加自己需要的部分進入庫。（ 2 ）尺寸驅(qū)動SolidWorks提供強大的尺寸驅(qū)動功能客觀支持參數(shù)化設(shè)計。這是邏輯之間的關(guān)系在尺寸設(shè)置儲存在Microsoft Excel的幾何參數(shù)。當一整套尺寸被集成為相應(yīng)參數(shù)的幾何形狀時，準確模型將可獲得。（ 3 ）設(shè)計平臺平臺的設(shè)計使得設(shè)計師可以建立多種部分配置參數(shù)指定的Microsoft Excel電子表格。設(shè)計平臺中保存文件的一部分，是用來存放尺寸，提供的功能和約束成形性能的，其中包括一些部分宣傳材料，注釋，和客戶使用必要條件。當適當?shù)某叽绫惶砑?，在設(shè)計平臺中將包含所有用以創(chuàng)建一個精確的模型裝配的必要信息。（ 4 ）結(jié)構(gòu)與管理這是一些結(jié)構(gòu)關(guān)系模具的基礎(chǔ)組件。當通過設(shè)計平臺提供某些參數(shù)設(shè)置后，這個分模塊將幫助模具設(shè)計師插入這些組件到裝配的結(jié)構(gòu)中，從而自動生成一個特定的模具基地裝置。4.2 分模一些分模算法 7-10 已在前面講過。這一過程中，分模模塊用來處理建立型芯和型腔。它是電腦輔助注塑模具設(shè)計系統(tǒng) 11 最重要的模塊。建立模具模型需要有一個設(shè)計模型，載方塊，可用的分型面。設(shè)計模型代表了成品，而載方塊代表模具組件總數(shù)。為了分開方塊可形成型芯和型腔，設(shè)計模型首先要從方塊中減去。然后將方塊通過分型面分成兩半，通常被稱為型芯和型腔。當熔融塑料注入型腔的時候，最終產(chǎn)品即由兩個對立的模具半凝固后，模具半擺脫部分沿分模方向D-D分開。那么實際的零件便可以獲得。圖 5顯示分模設(shè)計進程。（ 1 ）確定脫模方向在沿相反方向的型芯和型腔脫開便是便是脫模方向（圖6（a）條），產(chǎn)生分模線。脫模方向應(yīng)首先確定。分模的方向影響分模線的方向，從而影響復雜的模具的確定。在大多數(shù)情況下，分模的方向在確定的同時應(yīng)考慮幾何方向和生產(chǎn)問題。（ 2 ）“通過”黑洞的認識和補丁當產(chǎn)生一些通過生產(chǎn)而成的漏洞時，設(shè)計者必須指出漏洞的分模位置和產(chǎn)生了分型面的漏洞。這個被稱為“補丁”。表面需要并通過不定進行修復。由于上模具和下模具通過型腔連接，模具是不能分開型芯和型腔的。而且不能自動創(chuàng)建無補丁的洞（見圖6條（b）。（ 3 ）確定分型線和擠壓方向在成型時，一組部分的曲面成型由型芯與其他組的型腔組成。因此分型線之間的交叉關(guān)系使兩組表面形成型芯和型腔。所以分模線應(yīng)選在最大邊回路的表面。從分模的邊界線分開型芯或型腔的阻礙。擠壓方向路徑的分型線將在模糊時被跟隨。這是垂直的脫模方向，而不是平行的分開表面正常的側(cè)面的鑄模（見圖6（c）段）（ 4 ）生成分型面分型面是型芯和型腔相交的表面。分型面可以作為分裂的表面用以將模具分為兩半。兩種方法可用于產(chǎn)生分型面。掃描方法：在分型面生成由擠壓的分型線向外推至外邊界的型芯和型腔（見圖6 （d）項） 。輻射的方法：在SolidWorks的分型面上也可以用輻射所產(chǎn)生的分型線與指定的輻射距離相結(jié)合達到延長以外的外表面的載箱（見輻射表面圖6（e）。（ 5 ）建立載模塊載模塊可以將目標維起來，另外增加合適的空間圍繞其周邊進行計算。載模塊的尺寸，模具的強度，和成型參數(shù)是決定物體尺寸的基礎(chǔ)，可以有效地確定模具裝配尺寸（圖6（f）段）。（ 6 ）生成型芯和型腔為了創(chuàng)建型芯和型腔，載模塊必須分成兩個不同的模具半。首先，設(shè)計模型應(yīng)從模塊中減去。從而，一個空的空間內(nèi)才能獲得載模塊。然后分型面和修補表面被用作分裂面，將載模塊分成兩個半模具的型芯塊和型腔塊。最后，模擬模具開模過程和檢查干擾模具組件，模具半脫離部分表面不受任何外界干擾，沿方向d-d分模（圖6（g段）。5 結(jié)束語本文介紹了塑料注射模具設(shè)計技術(shù)和方法以及CAD注射模具的基本概念。通過Windows NT平臺，該方法已實施在SolidWorks99和API 。這使作為平臺的Windows的本地設(shè)計環(huán)境具有強大的裝配能力，易用性強，快速學習，而且價格便宜。CAD原型塑料注塑模具的設(shè)計使用Visual C + +已經(jīng)通過Windows NT平臺被發(fā)展和實施于SolidWorks99和API。這原型已開發(fā)和測試了幾個模塊，如數(shù)據(jù)籌備，填充設(shè)計，模具基地分模設(shè)計，模具設(shè)計等，已經(jīng)獲得了良好的效果。該程序為設(shè)計師提供了一個交互式CAD程序和Windows的本地設(shè)計環(huán)境，這既可以加快模具設(shè)計流程又可以增加標準化的便利性，同時又加速了模具制造。這一項目是一個面向?qū)ο蟮木幊陶Z言（Visual C + +），以確保其進一步發(fā)展和推廣。 這種方法主要針對注塑模具設(shè)計過程，但它也可以用于壓鑄模具設(shè)計。參考資料1 IMOLD Version 3.0, Manusoft Plastic Pte Ltd., 1998.2 Y.S. Yueh, R.A. Miller, Systematic approach to support design for manufacturability in injection molding and die casting, in: Proceed-ings of the Computers in Engineering ASME Database Symposium,ASME, New York, USA, 1995, pp. 755765.3 SolidWorks 99 Users Guide, SolidWorks Corporation.4 Unigraphics Solutions Inc. Parasolid On-Line Documentation Web,Parasolid V10.1.123.5 SolidWorks 99 API Documentation, SolidWorks Corporation.6 J.J. Shah, H. Dedhia, V. Pherwani, S. Solkhan, Dynamic interfacing of applications to geometric modeling services via modeler neutral protocol, Comput. Aided Des. 29 (12) (1997) 811824.7 A.Y.C. Nee, M.W. Fu, J.Y.H. Fuh, K.S. Lee, Y.F. Zhang, De-termination of optimal parting directions in plastic injection mold design, CIRP Ann. Manuf. Technol. 46 (1) (1997) 429432.8 Z.-Y. Zhou, S.-M. Gao, Z.-C. Gu, J.-Y. Shi, Automatic determination of the parting line in injection mold design, J. Comput. Aided Des.Comput. Graphics 12 (7) (2000) 512516.9 M.W. Fu, J.Y.H. Fuh, A.Y.C. Nee, Core and cavity generation method in injection mould design, Int. J. Prod. Res. 39 (1) (2001)121138.10 L. Kong, J.Y.H. Fuh, K.S. Lee, Auto-generation of patch surfaces for injection mould design, Proc. Inst. Mech. Eng. B 215 (1) (2001) 105110.11 C.K. Mok, K.S. Chin, J.K.L. Ho, An interactive knowledge-based CAD system for mould design in injection moulding processes, Int.J. Adv. Manuf. Technol. 17 (1) (2001) 2738.Journal of Materials Processing Technology 139 (2003) 8189A Windows-native 3D plastic injection mold design systemL. Kong, J.Y.H. Fuh, K.S. Lee, X.L. Liu, L.S. Ling, Y.F. Zhang, A.Y.C. NeeDepartment of Mechanical Engineering, National University of Singapore,10 Kent Ridge Crescent, Singapore 119260, SingaporeAbstract3D solid-modeling revolution has reached the design mainstream. While high-end 3D solid-modeling systems have been on engineersworkstation at large aerospace, consumer products, and automobile companies for years, many smaller companies are now making theswitch from workstations to PC. One reason for the shift is that the flexibility and advancement of Windows-native/NT has let softwaredevelopers create applications that are affordable and easy to use. High-end users are finding that mid-range solid modelers, such asSolidWorks, have met their needs.SolidWorks was chosen as the platform due to the Windows-native design environment, powerful assembly capabilities, ease-of-use,rapid learning curve, and affordable price. A Windows-native 3D plastic injection mold designs system has been implemented on an NTthrough interfacing Visual C+ codes with the commercial software, SolidWorks 99 and API. The system provides a designer with aninteractive computer-aided design environment, which can both speed up the mold design process and facilitate standardization. 2003 Elsevier Science B.V. All rights reserved.Keywords: Plastic injection mold; Windows; CAD; Parting1. IntroductionWith the broader use of plastics parts in a wide productrange, from consumer products to machinery, cars and air-planes, the injection molding process has been recognizedas an important manufacturing process. The mold designprocess is generally the critical path of a new product de-velopment. Conventionally, mold design has always been amuch “mystified” art, requiring years of experience beforeone can be relatively proficient in it. Due to the initial diffi-culty in learning this art, less and less people are benefitingfrom the experience and knowledge of the experts in thisfield. To change the current situation, one way is to use acomputer-aided design (CAD) system.CAD as an everyday term has grown to a broad range ofcapabilities and has applications in fields ranging from edu-cation for school teaching to three-dimensional mechanicaldesign. At the present time, most CAD systems provideonly the geometric modeling functions that facilitate thedrafting operations of mold design, and do not providemold designers with the necessary knowledge to design themolds. Thus, much “add-on” software, e.g. IMOLD, havebeen developed on high-level 3D modeling platforms toCorresponding author. Fax: +65-67791459.E-mail address: mpefuhyhnus.edu.sg (J.Y.H. Fuh).facilitate the mold design processes. Such an arrangementis advantageous in many ways. The 3D modeling platformprovides plug-in software with a library of functions as wellas an established user interface and style of programming.As a result, the development time for these “add-ons” issignificantly reduced.IMOLD(intelligent mold design) 1 is a knowledge-based software application, which runs on the UnigraphicsSolidWorks platform and is carried out by using the UserFunction provided. It is available on the UNIX and windowsoperation system. For years, mold design engineers havehad to deal with two different systems, UNIX and PC. Theformer is widely used in engineering applications whilstthe latter is used mainly in small and medium companies.Engineers also need to run corporate office applications suchas word processing, spreadsheets, and project managementtools, but these were not on their UNIX workstations.Fortunately, the remarkable development of computertechnology in the last decade has provided a way to changethis situation. The most significant change has been inthe area of computer hardware, i.e. the actual electroniccomponents associated with data processing, informationstorage, and display technology, in terms of both speedand memory. These have resulted in the more efficient useof the solid-modeling functions in a PC-based CAD/CAMsystem. With the increased availability of sophisticated,low-cost software for Windows, more and more engineers0924-0136/03/$ see front matter 2003 Elsevier Science B.V. All rights reserved.doi:10.1016/S0924-0136(03)00186-982L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189are using PC applications to get their jobs done. Thus thedevelopment of a new mold design application based on theWindows platforms is in high demand.High-end users are finding that mid-range solid modelers,such as SolidWorks, have met their needs. Developed fromthe beginning as a native Windows application, SolidWorksis one of the 3D mechanical design softwares for Win-dows. Its unique combination of production-level power,ease-of-use, and affordability is unmatched. SolidWorks99, the seventh major release of the companys mechan-ical design software for Windows NT, Windows 98 andbeyond provides an increased power and functionality in afully integrated solid modeler. Familiar conventions such aspoint-and-click, drag-and-drop, cut-and-paste, and seamlessdata sharing with other Windows software lead to produc-tivity gains. The ease-of-use without extensive training andat affordable pricing enables companies to install the sys-tem on every engineers desktop. One of its applications isfor mold design in the plastics industry. This latest appli-cation technology has added an entirely new dimension tothe mold design process.2. Injection mold designInjection molding uses temperature-dependent changes inmaterial properties to obtain the final shapes of discreteparts to finish or near-finish dimensions through the use ofmolds. In this type of manufacturing process, liquid materialis forced to fill and solidify inside the cavity of the mold 2.Firstly, the creation of a mold model requires a designmodel and a containing box. The design model representsthe finished product, whereas the containing box representsthe overall volume of the mold components.Fig. 1. Relationship among user applications, SolidWorks, Unigraphics and Parasolid.Injectionmolddesigninvolvesextensiveempiricalknowl-edge (heuristic knowledge) about the structure and the func-tions of the components of the mold. The typical processof a new mold development can be organized into four ma-jor phases: product design, moldability assessment, detailedpart design, insert/cavity design, and detailed mold design.In Phase 0, a product concept is pulled together by afew people (usually a combination of marketing and engi-neering). The primary focus of Phase 0 is to analyze themarket opportunity and strategic fit. In Phase I the typicalprocess-related manufacturing information is then addedto the design to produce a detailed geometry. The concep-tual design is transformed into a manufacturable one byusing appropriate manufacturing information. In Phase IIthe parting direction and parting lines location are added toinspect the moldability. Otherwise, the part shape is againmodified. In Phase III, the part geometry is used to establishthe shape of the mold core and cavity that will be used toform the part. Generally shrinkage and expansions need tobe considered so that the molding will be the correct sizeand shape at the processing temperature. Gates, runners,overflows, and vents also need to be added. The associationbetween geometric data and parting information is criticalat this point. Phase IV is related to the overall mechanicalstructure of the mold including the connection of the moldto the injection machine, a mechanisms for filling, cooling,and for ejection and mold assembly.3. MethodologyFor the reasons described above, SolidWorks 99 has beenused as the platform for the new mold design application.Fig. 1 shows a Windows-native 3D injection mold designL. Kong et al./Journal of Materials Processing Technology 139 (2003) 818983system compared with IMOLD. Users applications can becreated and run as a standalone exe file or as a User DLLor Extension DLL in SolidWorks. The SolidWorks Add-InManager allows users to control which third party softwareis loaded at any time during their SolidWorks session. Morethan one package can be loaded at once, and the settingswill be maintained across SolidWorks sessions.3.1. SolidWorksSolidWorksrecentlyemergedasoneofthe3Dproductde-sign software for Windows, providing one of the most pow-erful and intuitive mechanical design solution in its class. InSolidWorks, parts are created by building a “base feature,”and adding other features such as bosses, cuts, holes, fil-lets, or shells. The base feature may be an extrusion, revo-lution, swept profile, or loft. To create a base feature, sketcha two-dimensional geometric profile and move the profilethrough space to create a volume. Geometry can be sketchedon construction planes or on planar surfaces of parts.Feature-basedsolid-modelingprogramsaremakingtwo-dimensional design techniques obsolete. However,Unix-based solid-modeling software are expensive. Withthe introduction of SolidWorks for Microsoft Windows,the cost is less than the price of earlier dimension drivensolid-modeling programs 3.3.2. Parasolid as a 3D kernelSolidWorks uses Parasolid as a 3D kernel. Parasolid ker-nel modeling toolkit, is recognized as a worlds leading,production-proven core solid modeler. Designed as an exactFig. 2. SolidWorks API objects.boundary-representation solid modeler, Parasolid providesrobust solid-modeling, generalized cellular modeling and in-tegrated surface/sheet modeling capabilities and is designedfor easy integration into CAD/CAM/CAE systems to giverapid time to market. Its extensive functionality is suppliedas a library of routines with an object-oriented program-ming interface. It is essentially a solid modeler, which canbe used to 4: (i) build and manipulate solid objects; (ii)calculate mass and moments of inertia, and perform inter-ference detection; (iii) output the objects in various picto-rial ways; (iv) store the objects in some sort of database orarchive and retrieve them later; and (iv) support freeformsurfaces.3.3. API 5The SolidWorks application programming interface (API)is an OLE programming interface to SolidWorks. The APIcontainshundredsoffunctionsthatcanbecalledfromVisualBasic, VBA (Excel, Access, etc.), C, C+, or SolidWorksmacro files. These functions provide the programmer withdirect access to SolidWorks functionality such as creatinga line, extruding a boss, or verifying the parameters of asurface.The API interface uses an object-oriented approach. Allthe API functions are methods or properties that apply to anobject. Fig. 2 is one particular view of the SolidWorks APIobjects.SolidWorks exposes functionality through OLE automa-tion using Dispatch and also through standard COM objects.The Dispatch interface 6 will package arguments and re-turn values as Variants so that languages such as Basic can84L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189handle them. A COM implementation gives your applica-tion more direct access to the underlying objects, and sub-sequently, increased performance.4. ImplementationsThe facts that SolidWorks API interface uses an object-oriented approach and the API functions allows one toFig. 3. System infrastructure for the mold design application.choose an object-oriented language, e.g. Visual C+, asthe programming language. Using this methodology, aWindows-based 3D injection mold design application is de-veloped on Windows NT through interfacing of the VisualC+ code with a commercial software, SolidWorks 99. Inthis application the mold design process is divided into sev-eral stages, providing the mold designer with a consistentmethod of creating the mold design. The overview of thisframework is shown in Fig. 3. Each stage can be consideredL. Kong et al./Journal of Materials Processing Technology 139 (2003) 818985as an independent module of the program. Several moduleshave been successfully developed using SolidWorks. Twoof them, mold base module and parting module are shownbelow.4.1. Mold base moduleThe mold base module can automatically create parame-tric standard mold bases, with all its components andaccessories, like HASCO, DME, HOPPT, LKM andFUTABA. This module allows easy customization ofmold bases commonly used by designers. Key features in-clude availability of standard mold base components likesupport pillars and sprue bushings, 2-plate and 3-platemold bases, and customization of non-standard moldbases.The mold base module consists of four main sections,namely, the component library (including standard andnon-standard part library), the design table, the dimensiondriven functionality, and structure relation management.Here, the dimension driven functionality is provided bySolidWorks to support for the application. The details forthe mold base module are shown in Fig. 4.(1) Component libraryIn order to strengthen the mold design capability inthis increasingly competitive world, lowering the designcost and cycle time, reducing the man-power, and au-tomation are major factors in achieving this purpose. Inother words, it is necessary to have computer softwarethat is able to easily create, modify, and analyze themold design components, and update the changes in adesign model. To achieve this, a 3D component libraryis provided to store standard and non-standard partsdata, whose dimensions are stored in Microsoft Excel.By specifying the appropriate dimensions, these com-ponents can be generated and inserted into the assemblystructure. This library is completely customizable anddesigners are able to add their own parts into the library.(2) Dimension drivenSolidWorks provides strong dimension driven func-tionality to support parametric design. It is the logi-cal relationship between the dimension sets stored inMicrosoft Excel and the geometry. When a set of di-mension is integrated with the corresponding parameterset of the geometry of an object, the exact model canbe then obtained.(3) Design tableA design table allows a designer to build multipleconfigurations of parts by specifying parameters in anembedded Microsoft Excel spreadsheet. The designtable is saved in the part file and is used to store thedimensions, the suppression of features and the con-figuration properties, including part number in a billof materials, comments, and customer requirements.When appropriate dimensions are added, the designFig. 4. Details of the mold base module.table will contain all the information needed to createan accurate model of the assembly.(4) Structure relation managementThis section records the structure relations betweenmold base components. When supplied with certainparameter set from the design table, this sub-modulehelps the mold designer to insert these componentsinto the assembly structure, thus a specific mold baseassembly can be automatically generated.4.2. Parting moduleSome of the parting algorithms 710 have been reportedpreviously.Inthisdevelopment,partingmoduleisdevelopedto handle the creation of cores and cavities. It is one of themost important modules in a computer-aided injection molddesign system 11. The creation of a mold model needs tohave a design model, a containing box, and parting surfacesavailable. The design model represents the finished product,whereas the containing box represents the overall volume86L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189Fig. 5. Parting design module.of the mold components. In order to split the box into thecore and cavity, the design model is first subtracted fromthe box. The parting surfaces are then used to separate thecontaining box into mold halves, often referred as the coreand cavity. When melt plastics is injected into the cavity, thefinished product is formed by the two opposing mold halves.After solidification, both mold halves move away from thepart along the parting directions d and d, respectively. Theactual part is then obtained. Fig. 5 shows the parting designprocess.(1) Determination of the parting directionThe pair of opposite directions along which the coreand cavity open are the parting directions (Fig. 6(a).L. Kong et al./Journal of Materials Processing Technology 139 (2003) 818987Fig. 6. Parting design process: (a) determination of parting direction; (b) generation of patching surfaces; (c) determination of parting lines and extrudingdirections; (d) swept parting surfaces; (e) radiated parting surfaces; (f) creation of containing box; (g) generation of the core and cavity.88L. Kong et al./Journal of Materials Processing Technology 139 (2003) 8189To generate the parting lines, the parting directionshould be determined first. The parting direction in-fluences the orientation of the parting line that de-termines the complexity of the mold. In most cases,partingdirectionsaredeterminedbyconsideringboth geometry and manufacturing issues at the sametime.(2) Recognition and patching the “through” holesWhen there are some through holes in a product, thedesigners must indicate the parting location of the holesand generate the parting surfaces in these holes. Thisis called “patching” in this paper. Surfaces are neededand used to patch the through holes. Because the uppermold and the lower mold are connected at the throughhole, a mold cannot be separated and the core and thecavity cannot be created automatically without patchingthose holes first (see Fig. 6(b).(3) Determination of parting lines and the extrudingdirectionsIn molding, one group of the parts surfaces is moldedby the core, and the other group is molded by the cavity.The parting lines are therefore the intersection betweenthe two groups surfaces molded by the core and cavity.The parting lines are chosen from the largest edge-loopin the surface groups.From the parting lines to the boundary of the coreor cavity block, the extruding direction is the path thatthe parting lines will follow during sweeping. It is per-pendicular to the parting direction but parallel to thesurface normal of the side face of the mold box (seeFig. 6(c).(4) Generation of the parting surfacesThe parting surfaces are the mating surfaces of thecore and cavity. The parting surfaces can be used asthe splitting surfaces to cut a mold into two halves.Two methods can be used to generate the partingsurfaces.Sweep method: The parting surfaces are generatedby extruding the parting lines outwards to the outsideboundary of the core and cavity (see Fig. 6(d).Radiate method: In SolidWorks, the parting sur-faces can also be created by using radiating the partinglines with a specified radiate distance that is largeenough to extend the surface beyond the outsidefaces of the containing box (see radiate surfaces inFig. 6(e).(5) Creation of containing boxA containing box encloses the object and the addi-tional suitable space around its periphery is computed.The size of a containing box is determined based on thedimension of the object, the strength of the mold, andthe molding parameters that can effectively define thesize of the mold assembly (Fig. 6(f).(6) Generation of cores and cavitiesIn order to generate cores and cavities, the containingbox must be split into two separate mold halves. Firstly,the design model is subtracted out from the box. Thus,an empty space is obtained inside the containing box.Then parting surfaces and patching surfaces are used asthe splitting surfaces to separate the containing box intotwo mold halves, the core block and the cavity block.Finally, after simulating the mold opening process andchecking the interference among mold components, themold halves are moved away from the part surfaceswithout any interference along the parting directions dand d, respectively (Fig. 6(g).5. ConclusionsThis paper introduces the basic concept of plastics injec-tion mold design and a methodology of CAD for injectionmold. Through Windows NT platform, the methodology hasbeen implemented on