盒形件沖壓工藝分析及復合模設計-沖壓模具【含11張CAD圖紙+PDF圖】

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2014年機電工程學院畢業(yè)設計(論文)進度計劃表 學生姓名： 戴瑤 學號：1000110117 序號 起止日期 計劃完成內(nèi)容 實際完成內(nèi)容 檢查日期 檢查人簽名 1 2013.12.17—12.23 指導老師對本組人員課題進行首輪分析講解，并對設計的思路以及資料的查找進行輔導。 2 2013.12.24—12.30 查閱相關資料結合課題整理出設計的思路，方法。 3 2013.12.31-2014.1.6 上圖書館借閱資料，書籍，上網(wǎng)搜索資料，。 4 2014.1.7-1.13 上網(wǎng)搜索相關資料即任務書里要求的翻譯不少于四萬字符的指定英文資料翻譯。 5 3.4-3.10 初步確定要設計的方案 6 3.11-3.17 對工件進行工藝分析以及初步排樣 7 3.18-3.24 確定排樣以及沖裁方案并且開始進行初步計算 8 3.25-3.31 計算工藝中各個力 (本表同時作為指導教師對學生的16次考勤記錄) 2014年機電工程學院畢業(yè)設計進度計劃表（續(xù)） 學生姓名：戴瑤 學號：1000110117 序號 起止日期 計劃完成內(nèi)容 實際完成內(nèi)容 檢查日期 檢查人簽名 9 4.01-4.07 凸凹刃口尺寸的計算以及對模具結合的初步設計 10 4.08-4.14 初步進行落料凹模以及拉深沖孔凸凹模的分析與計算 11 4.15-4.21 上墊板，壓邊圈，卸料導料板，凸模固定板的分析與計算 12 4.22-4.28 定位方式的選擇與計算 13 4.29-5.05 模具進行裝配和調(diào)試 14 5.06-5.12 進行二維制圖 15 5.13-5.19 二維圖修改和論文進行格式更改 16 5.20-5.26 完成畢業(yè)設計，提交論文 任務下達時間：2013年12月17日　　　　(本表同時作為指導教師對學生的16次考勤記錄) 第 2 頁 共 2 頁 編號： 　畢業(yè)設計(論文)任務書 題 目：盒形件沖壓工藝分析及復合模 設計 學　　院： 機電工程學院 專 業(yè)： 機械設計制造及其自動化 學生姓名： 戴瑤 學 號： 100110117 指導教師單位： 機電工程學院 姓 名： 楊曉清 職 稱： 講 師 題目類型：¨理論研究 ¨實驗研究 t工程設計 ¨工程技術研究 ¨軟件開發(fā) 2013年12月13日 注：1、本任務書一式一份，院辦留存，發(fā)給學生電子稿，任務完成后附在 說明書內(nèi)。 2、任務書均要求打印，打印字體和字號按照《本科生畢業(yè)設計（論文）統(tǒng)一格式的規(guī)定》執(zhí)行。 3、以下標題為四號仿宋體、加粗，正文中文用小四宋體，英文用小四Times New Roman，日期采用阿拉伯數(shù)字。 4、“一、畢業(yè)設計（論文）的內(nèi)容、要求”位于頁面最頂端，“任務下達時間”位于新頁面最頂端。 　　5、請不要修改最后一頁（即“任務下達時間”所在頁的內(nèi)容） 一、畢業(yè)設計（論文）的內(nèi)容 板料的沖壓成型是一種重要的金屬加工方式，被廣泛地應用工業(yè)生產(chǎn)領域中。模具是工業(yè)生產(chǎn)的基礎工藝裝備。用模具生產(chǎn)制件所具備的高精度、高復雜程度、高一致性、高生產(chǎn)率和低消耗,是其他加工制造方法所不能比擬的。 畢業(yè)設計工作內(nèi)容------------------------------裝 ---------------- 訂 ----------------- 線---------------------------------- ： 利用模具設計專業(yè)知識，對盒形件進行工藝分析，給出合理的工藝方案并設計出整套模具。整個畢業(yè)設計的內(nèi)容包括課題的調(diào)研,資料的搜集與消化; 對沖壓成形進行工藝分析,提出工藝措施；確定毛料形狀、尺寸和下料方式以及推料卸料方式。確定各項工序在模具中的具體布局。模具的工藝計算。模具結構設計以及計算相關結構尺寸。根據(jù)尺寸以及生產(chǎn)需要選擇相應的沖壓設備。 二、畢業(yè)設計（論文）的要求與數(shù)據(jù) 要求： 1.在深入分析工件的結構和工藝的基礎上，給出兩種模具設計方案，經(jīng)方案比較后擇優(yōu)?；诠に嚪桨?，設計出相應復合沖壓模具。 2.模具結構簡單、操作安全、加工方便。 3.完成畢業(yè)設計說明書（論文）一份，內(nèi)容包括工件結構分析、工藝分析、模具方案的論證、進行總體結構設計、制定主要件的工藝規(guī)程、必須的工藝計算、制造工藝以及一定的技術經(jīng)濟分析等。 三、畢業(yè)設計（論文）應完成的工作 1、完成二萬字左右的畢業(yè)設計說明書（論文）；在畢業(yè)設計說明書（論文）中必須包括詳細的300-500個單詞的英文摘要； 2、獨立完成與課題相關，不少于四萬字符的指定英文資料翻譯（附英文原文）； 3、繪圖工作量折合A0圖紙3張以上，其中必須包含兩張A3以上的計算機繪圖圖紙； 四、應收集的資料及主要參考文獻 [1] 傅建等． 模具制造工藝學[M] ．北京：機械工業(yè)出版社，2004． [2] 高為國． 模具材料[M] ．北京：機械工業(yè)出版社，2004． [3] 凸光棋．沖模技術[M] ．北京：機械工業(yè)出版社,2002． [4] ATTILA MUDERRISOGLU,MAKOTO MURATA,MUSTAFAA,et al.Bending flanging and hemming of aluminum sheet-an experimental studyJ ．Journal of Materials Processing Technology,1996,59(2) :10-17． [5] 吳宗澤．機械設計實用手冊[M] ．北京：機械工業(yè)出版社，2002． [6] 沖模設計手冊編寫組．沖模設計手冊[M] ．北京：機械工業(yè)出版社,1999． [7] 劉航．模具技術經(jīng)濟分析[M]．北京：機械工業(yè)出版社，2002：89-100． [8] 模具制造手冊編寫組．模具制造手冊[M] ．北京：機械工業(yè)出版社，2003． [9] 劉友和．金工工藝設計[M] ．廣東：華南理工大學出版社，1991． 五、試驗、測試、試制加工所需主要儀器設備及條件 計算機一臺 CAD設計軟件（CAXA等）  任務下達時間： 2013年12月17日 畢業(yè)設計開始與完成時間： 2013年12月17日至 2014年05 月26日 組織實施單位： 教研室主任意見： 簽字： 2013年12月14日 院領導小組意見： 簽字： 2013 年12月16日 編號： 　畢業(yè)設計(論文)開題報告 題 目：盒形件沖壓工藝分析及復合模 設計 學　　院： 機電工程學院 專 業(yè)： 機械設計制造及其自動化 學生姓名： 戴瑤 學 號： 1000110117 指導教師單位： 機電工程學院 姓 名： 楊曉清 職 稱： 講 師 題目類型：¨理論研究 ¨實驗研究 t工程設計 ¨工程技術研究 ¨軟件開發(fā) 2013年12月27日 開題報告填寫要求 ? 1．開題報告作為畢業(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。此報告應在指導教師指導下，由學生在畢業(yè)設計（論文）工作前期內(nèi)完成，經(jīng)指導教師簽署意見審查后生效。 ?2．開題報告內(nèi)容必須用黑墨水筆工整書寫，或按教務處統(tǒng)一設計的電子文檔標準格式打印，禁止打印在其它紙上后剪貼，完成后應及時交給指導教師簽署意見。 ?3．學生查閱資料的參考文獻應在5篇及以上（不包括辭典、手冊），開題報告的字數(shù)要在1000字以上。 ?4．有關年月日等日期的填寫，應當按照國標GB/T 7408—94《數(shù)據(jù)元和交換格式、信息交換、日期和時間表示法》規(guī)定的要求，一律用阿拉伯數(shù)字書寫。如“2004年4月26日”或“2004-04-26”。 ?5．“指導教師（簽字）”日期填寫成在2013年12月27日~ 31日之間的某個日期；“開題小組組長（簽字）”日期填寫成在2014年1月4日~9日之間的某個日期。 1． 畢業(yè)設計的主要內(nèi)容、重點和難點等 1．主要設計內(nèi)容 板料的沖壓成型是一種重要的金屬加工方式，被廣泛地應用工業(yè)生產(chǎn)領域中。模具是工業(yè)生產(chǎn)的基礎工藝裝備。用模具生產(chǎn)制件所具備的高精度、高復雜程度、高一致性、高生產(chǎn)率和低消耗,是其他加工制造方法所不能比擬的。 利用模具設計專業(yè)知識，對盒形件進行工藝分析，給出合理的工藝方案并設計出整套模具。整個畢業(yè)設計的內(nèi)容包括課題的調(diào)研,資料的搜集與消化; 對沖壓成形進行工藝分析,提出工藝措施；確定毛料形狀、尺寸和下料方式以及推料卸料方式。確定各項工序在模具中的具體布局。模具的工藝計算。模具結構設計以及計算相關結構尺寸。根據(jù)尺寸以及生產(chǎn)需要選擇相應的沖壓設備。 1.1零件的工藝性分析：結構與尺寸精度，材料的選取。 1.2 確定沖裁工藝方案：生產(chǎn)中現(xiàn)有沖壓工藝方案為：落料，拉深，整形，切邊，沖底面孔、翻邊，沖側面孔。對于需要經(jīng)過落料、拉深、整形、切邊、沖底面孔、翻邊、沖側面孔等多道工序制造的零件，生產(chǎn)中各工序分開，模具制造簡單，但需要多套模具，模具套數(shù)多、效率低，工藝路線長、各道工序分離，很難保證零件的精度要求；而且加工自動化程度不高，生產(chǎn)成本高，已不適應現(xiàn)代化的加工現(xiàn)場要求。因此要解決的技術問題是提出一種將倒裝拉深、整形、沖底面孔、翻邊、沖側面孔等多道工序，集中在一套復合的沖壓模具上完成，使操作方便，節(jié)省工時，保證零件的精度，提高勞動生產(chǎn)率。 1.3確定模具總體結構方案：模具方案的論證、進行總體結構設計。模具類型，操作與定位方式，卸料與出件方式，模架類型及精度。 1.4工藝與設計分析計算：確定沖裁工藝方案及相關計算。工件結構分析、工藝分析、制定主要件的工藝規(guī)程、必須的工藝計算、制造工藝以及一定的技術經(jīng)濟分析等。 1.5排樣設計與計算：計算沖壓力壓力中心，初選壓力機。模具閉合高度的確定和壓力機的校驗。計算凹、凸模刃口尺寸及公差。 1.6設計選用模具零、部件，繪制模具總裝圖：凹模設計，凸模設計。 1.7技術經(jīng)濟相關分析 2.重點與難點 確定沖裁工藝方案及排樣方案的確定與計算，模具中主要尺寸的設計與計算，如成型零件的設計及尺寸計算（如步進、沖壓間隙等）以及模具結構的設計。模具的裝配與調(diào)試。 2．準備情況（查閱過的文獻資料及調(diào)研情況、現(xiàn)有設備、實驗條件等） 1.了解國內(nèi)現(xiàn)狀 近半個世紀以來，我國的沖壓工藝和其他生產(chǎn)工藝一樣，得到了迅速的發(fā)展。我國模具標準化程度正在不斷提高，目前我國模具標準件使用覆蓋率已達到30左右〔國外發(fā)達國家一般為80)有些單位建立了具有現(xiàn)代規(guī)模和先進技術的沖壓生產(chǎn)車間，并建立了專門研究沖壓技術的科研機構及專業(yè)性工廠，培養(yǎng)了大批從事沖壓科技人員，廣泛開展了沖壓生產(chǎn)的科技及學術活動，編輯出版了各種沖壓技術書籍，從而使沖壓生產(chǎn)技術得到了迅速發(fā)展。 模具是工業(yè)產(chǎn)品生產(chǎn)應用的重要工藝設備，按成型的對象和方式來分，模具大致可以分為三類：金屬板料成型模具（如冷沖壓模）；金屬體積成型模具（如鍛造模，粉末，冶金模，壓鑄模等）非金屬材料成型模具（如塑料模，玻璃模,陶瓷模等），其中使用量最大的是沖壓模和塑料模，約占模具總量的80%左右。 沖壓工藝與沖壓設備正在不斷地發(fā)展，特別是精密沖壓。高速沖壓、多工位自動沖壓以及液壓成形、超塑性沖壓等各種沖壓工藝的迅速發(fā)展，把沖壓的技術水平提高到了一個新高度。新型模具材料的采用和鋼結合金、硬質(zhì)合金模具的推廣，模具各種表面處理技術的發(fā)展，沖壓設備和模具結構的改善及精度的提高，顯著地延長了模具的壽命和擴大了沖壓加工的工藝范圍。沖壓模具成型的零件機械性能好，沖壓件普遍具有重量輕，強度高，表面成形質(zhì)量好的特點。因此，研究沖壓模具具有極大的意義與作用。 2.參考文獻 [1] 傅建等． 模具制造工藝學[M] ．北京：機械工業(yè)出版社，2004． [2] 高為國． 模具材料[M] ．北京：機械工業(yè)出版社，2004． [3] 凸光棋．沖模技術[M] ．北京：機械工業(yè)出版社,2002． [4] ATTILA MUDERRISOGLU,MAKOTO MURATA,MUSTAFAA,et al.Bending flanging and hemming of aluminum sheet-an experimental studyJ ．Journal of Materials Processing Technology,1996,59(2) :10-17． [5] 吳宗澤．機械設計實用手冊[M] ．北京：機械工業(yè)出版社，2002． [6] 沖模設計手冊編寫組．沖模設計手冊[M] ．北京：機械工業(yè)出版社,1999． [7] 劉航．模具技術經(jīng)濟分析[M]．北京：機械工業(yè)出版社，2002：89-100． [8] 模具制造手冊編寫組．模具制造手冊[M] ．北京：機械工業(yè)出版社，2003． [9] 劉友和．金工工藝設計[M] ．廣東：華南理工大學出版社，1991． 3．現(xiàn)有設備 計算機一臺，CAD設計軟件（CAXA等）。 3、實施方案、進度實施計劃及預期提交的畢業(yè)設計資料 1.實施方案 在進行沖壓模具結構設計時，首先要在深入分析工件的結構和工藝的基礎上，確定兩套方案。基于工藝方案，設計出相應復合沖壓模具。 對沖壓成形進行工藝分析,提出工藝措施；確定毛料形狀、尺寸和下料方式以及推料卸料方式。確定各項工序在模具中的具體布局。模具的工藝計算。模具結構設計以及計算相關結構尺寸。根據(jù)尺寸以及生產(chǎn)需要選擇相應的沖壓設備。 運用大學期間所學的專業(yè)課程知識。理論知識和課程設計及生產(chǎn)實習中所學到的實踐知識，正確的解決沖壓模具設計中的沖裁件的工藝性分析、工藝方案的論證及確定、工藝設計排樣設計及具體數(shù)據(jù)的理論計算與實際校核驗證、模具結構型式設計和零件加工工序設計等題目。熟練掌握查閱手冊、圖標、資料等參考文獻。充分利用與本次題目有關的沖壓設計有關的資料，做到科學的，熟練的運用。與老師和同學進行交流溝通，交換心得，取長補短。 優(yōu)選方案初步定為：1落料，2拉深、整形、沖底面孔、翻邊、沖側面孔，3切邊 2.進度實施計劃 （1）2013年12月~2014年1月接受任務書、搜集分析資料完成開題報告； （2）2014年1月~2月徹底消化資料、初步確定成型方案完成外文翻譯； （3）2014年2月~4月設計初稿階段，完成總體設計圖、部件及零件圖； （4）2014年4月~5月中期工作階段，完善設計圖紙、編寫設計說明書； （5）2014年5月~6月終極工作階段，圖紙說明書修改定稿，整理資料準備答辯 3.預期提交的畢業(yè)設計資料 (1) 完成二萬字左右的畢業(yè)設計說明書（論文）；在畢業(yè)設計說明書（論文）中必須包括詳細的300-500個單詞的英文摘要； (2) 獨立完成與課題相關，不少于四萬字符的指定英文資料翻譯（附英文原文）； (3) 繪圖工作量折合A0圖紙3張以上，其中必須包含兩張A3以上的計算機繪圖圖紙； 指導教師意見 指導教師（簽字）： 2013年12月　　日 開題小組意見 開題小組組長（簽字）： 2014年1 月　　日 院（系、部）意見 主管院長（系、部主任）簽字： 2014年1月　　日 - 5 - 畢業(yè)設計（論文）中期檢查表（指導教師） 指導教師姓名：楊曉清 　　 填表日期：2014 年 4 月 18 日 學生學號 1000110117 學生姓名 戴瑤 題目名稱 盒形件沖壓工藝分析及復合模設計 已完成內(nèi)容 （請根據(jù)任務書進度計劃認真檢查） 選擇畢業(yè)設計題目，并查找相關資料 撰寫畢業(yè)設計開題報告 翻譯20000字外文資料 設計總體思路并列提綱，開始著手設計分析，包括對確定毛料形狀、尺寸和下料方式以及推料卸料方式。確定各項工序在模具中的具體布局。模具的工藝計算。模具結構設計以及計算相關結構尺寸。根據(jù)尺寸以及生產(chǎn)需要選擇相應的沖壓設備。 檢查日期： 完成情況 □全部完成 t按進度完成 □滯后進度安排 存在困難 1．在分析零件尺寸上，不能正確表示零件。 2．如何確定沖裁工藝方案及排樣方案的確定與計算，模具中主要尺寸的設計與計算，如成型零件的設計及尺寸計算（如步進、沖壓間隙等）以及模具結構的設計。模具的裝配與調(diào)試。最終完成復合模的設計。 解決辦法 向指導老師進行了交流，老師給予了指導。確定了零件的尺寸。在模具設計中采用分塊形式進行計算設計。從而解決了復雜的現(xiàn)狀。利用資料文獻查表，進行計算凹、凸模刃口尺寸及公差。重點在于各套模具的確定，為之后的復合模設計奠下了基礎。 預期成績 □優(yōu) 秀 □良 好 □中 等 □及 格 □不及格 建 議 教師簽名： 教務處實踐教學科制表 說明：1、本表由檢查畢業(yè)設計的指導教師如實填寫；2、此表要放入畢業(yè)設計（論文）檔案袋中； 3、各院(系)分類匯總后報教務處實踐教學科備案。 Manufacturing of Dies and Molds Taylan Altan (I), Blaine Lillg, Y.C. Yen Engineering Research Center for Net Shape Manufacturing Department of Industrial, Welding, and Systems Engineering The Ohio State University, Columbus, Ohio, U.S.A. Submitted by Taylan Altan (I), Columbus, Ohio, U.S.A. 1 2 Abstract The design and manufacturing of dies and molds represent a significant link in the entire production chain because nearly all mass produced discrete parts are formed using production processes that employ dies and molds. Thus, the quality, cost and lead times of dies and molds affect the economics of producing a very large number of components, subassemblies and assemblies, especially in the automotive industry. Therefore, die and mold makers are forced to develop and implement the latest technology in: part and process design including process modeling, rapid prototyping, rapid tooling, optimized tool path generation for high speed cutting and hard machining, machinery and cutting tools, surface coating and repair as well as in EDM and ECM. This paper, prepared with input from many ClRP colleagues, attempts to review the significant advances and practical applications in this field. Keywords: Die, Mold, Manufacturing. 0 INTRODUCTION The authors would like to thank all of the colleagues who responded to the request for information in preparing this review paper, namely to Prof. Klocke - WZL Aachen, Prof. Tonshoff - IFW Hannover, Prof. Wertheim - Iscar, Ltd. (Israel), Profs. Kruth and Lauwers - Catholic University Leuven, Prof. Rasch - NTNU Trondheim, Prof. Geiger and Dr. Engel - LFT Erlangen, Prof. Weinert - ISF Dortmund, Dr. Leopold - GFE Chemnitz, Mr. Reznick - Extrude Hone Corp., Prof. Gunasekera - Ohio University, Prof. Bramley - University of Bath, Prof. Bueno - Fundacion Tekniker, Prof. Neugebauer and Dr. Lang - Fraunhofer IWU Chemnitz. Thanks are also due to our co-workers and the ERCINSM, as well as the co-workers of Prof. Klocke at WZL, and of Prof. Tonshoff at IFW, who assisted us in collecting the references and in the preparation of figures. Furthermore, we appreciate the response that we received from many of the participants of the 2001 Mold Making Conference. 1 BACKGROUND Production of industrial goods requires manufacturing of discrete parts that are sub-assembled and assembled to a product ready for the customer. The manufacturing of nearly all mass produced discrete parts require dies and molds that are used in production processes such as forging, stamping, casting, and injection molding. Thus, the design and manufacturing of dies and molds represent a very crucial aspect of the entire production chain. This can be illustrated by the following observations: Dies and molds, similar to machine tools, may represent a small investment compared to the overall value of an entire production program. However, they are crucial, as are machine tools, in determining lead times, quality and costs of discrete parts. Manufacturing and try-out of new dies and molds may be critical in determining the feasibility and lead-time of an entire production program. For example, in manufacturing automotive interior components by in- mold lamination complex molds that are used may cost up to $0.5 million and require 6 to 9 months for try-out and robust process development using production equipment. Considering that the OEMs require sample parts, produced on production equipment (not prototypes), 6 to 9 months prior to start of production (SOP) of a new car model, the significance of mold making becomes obvious. The quality of the dies and molds directly affect the quality of the produced parts. Excellent examples are molds used for injection molding lenses, or dies used for precision forging of automotive drive train components. 1 1.1 Significance of the Technology The observations listed above illustrate that die and mold making has a key position in manufacturing components in virtually all industries but especially in transportation, consumer electronics and consumer goods industries. The effectiveness of die making affects the entire manufacturing cycle so that this technology must be considered to be a very essential link in the total production chain . Die and mold making covers a broad range of activities, including: a) manufacturing of new dies and fixtures, b) maintenance and modifications, and c) technical assistance and prototype manufacturing for the customer, Figure 1 I. Process development and die try-out as well as die maintenance are especially important because they tie up expensive production equipment and affect lead times. These activities must be scheduled and completed within very rigid deadlines. Such requirements make scheduling in a die shop an extremely challenging task. The automotive industry constantly tries to reduce the development time for new models which puts enormous pressure on die makers and requires new production systems 2. 1.2 Variety of Dies and Molds The four major processes that utilize dies and molds a) require different technologies for design and production, and b) utilize different terminologies, Figure 2 3. For example, die-casting dies have more deep and thin rib cavities that cannot be easily machined than injection molding molds. As a result five times more plunge EDM machines are used in the die casting industry than in the injection molding industry. Another example is the extensive, nearly 50 %, use of wire EDM machines for making blanking dies while only 5 % of these machines are used to make extrusion dies. As seen in Figure 2, large deep drawing and stamping dies are made by machining cast iron or steel structures while dies for forging, die casting and plastics molding are made from tool steel blocks, involving considerable rough machining operations. Injection molding molds and die casting dies allow the production of rather complex parts with undercuts andlor hollow geometries. Thus, these tools usually have multiple motion slides and punches as well as cooling channels that complicate the manufacturing process. Dies and molds are composed of functional (cavity, core insert, punch) and support components (guide pins, holder, die plate). Often support components and a number of holes need only 2D or 2% D machining, but may require 50 to 60% of the total manufacturing time. This fact is often neglected but must be considered in effective planning of the machining operations. While metal cutting and EDM are the major methods used for die and mold making, hobbing, micro machining and chemical etching methods are also used for manufacturing molds for various applications. Figure 1 : Position of die and mold machining in product life cycle I. 1.3 Economics of DielMold Making According to a recent survey 4, major issues that face die and mold makers are similar in all industrialized countries, namely: 1. Declining prices and profit margins so that there is a strong need to control and reduce costs. 2. Demands for building dieslmolds in far less time (nearly 50 % less) than before. 3. Need for extended customer service (data handling, advice, prototype parts, assistance in process development) . 4. Lack and cost of skilled labor, which leads to the need to provide extensive training to employees and to utilize “new technologies“. 5. Globalization that leads to increased foreign competition, especially from developing countries where skill levels are increasing while salaries are comparatively low. Priorities differ according to countries surveyed; for example while North American and German mold makers are mainly concerned with foreign competition, Japanese companies concentrate on developing new markets. In all countries, however, the acceptance of “new technologies” is recognized to be one essential component that can lead to innovation and integration that are essential for growth 5. New technologies are understood to include not only manufacturing techniques (high speed milling, hard machining, automation, process modeling, etc.) but also pre- and post-manufacturing, e.g. cost estimating and control, documentation, training and operations management. Thus, two essential components for achieving a competitive position in dielmold industry are: a) capabilities of personnel, and b) utilization of optimized and innovative production techniques 161. Figure 2: Workpiece characteristics in die and mold making 3. Successful dielmold makers recommend that, for a financially successful die making operation, it is necessary to: 1, Establish quantitative methods for cost estimating. In this industry cost estimates are often based on the “past experience” and “feel” of the die maker and comparison with “similar” dies. As a result the accuracy of the estimations, that may determine profit or loss, may be in the range off 20 % 7. Determine the entire process chain for die making, from inquiry until delivery to the customer. Identify all cost parameters and quantify cost factors, eventually by reviewing past history (data collection for working hours, contracts, cost accounting). Establish a contractual basis so that items non- specified in the contract are only provided at extra charge 8. In order to maintain deadlines, focus on contract initialization and not on assembly of the mold, where considerable manpower is involved and it is difficult to change a schedule. Provide services to the customer mainly in data management at the start and during production but also during process development with complex molds that may require considerable try-out time. For successful die makers quality is a given. The time for work in progress, or storage time, can be a significant factor in low volume production, such as dielmold making. In this application it is estimated that 70% of the “total production time” consists of storage time when no value is added to the product. This situation can only be improved by increasing machining capacity, machine utilization rate, orland improving the efficiency of the part handling operations 9. To reduce the time for work in progress, many high technology die shops have separated tool path generation from engineering and design of the dies. While the latter is done in the engineering department, tool path generation is done on the shop floor by the machine operator. 2 In manufacturing discrete parts using dies or molds, the part design must be compatible with the process in order to assure the production of high quality parts at low cost with short lead times. Thus, part and process designs are best considered simultaneously, which is often not the case in practice. This objective can only be achieved through good communication between the product and tool designer, who may be in different companies (OEM and supplier) andlor locations. PART, DIE AND PROCESS DESIGN Original Equipment Fi rst-Ti er Manufacturers Suppliers Subtier Suppliers I CADKEY CADDS CATIA I-DEAS Unigraphics lntegraph CADDS I-DEAS CATIA ProlEN GI N E E R Unigra phi cs Figure 3: Proliferation of CAD systems in chain lo. ARIES Applicon ANVIL AutoCAD ProlENGlNEER I- D EAS PDGS HP lntegraph EUCLID CATIA supply The use of different CAD systems by OEMs and suppliers further complicates communication within the supply chain. Figure 3, taken from lo, shows the proliferation of CAD systems in the top three tiers of the North American automobile industry. Because die and mold making firms tend to be third or fourth-tier suppliers, the “interoperability problem” of reliably transferring CAD data between firms is particularly acute in this industry. It is well known that the design actually represents only a small portion, 5 to 15%, of the total production cost of a part. However, decisions made at the design stage have a profound effect upon manufacturing and life cycle costs of a product. In addition to satisfying the functional requirements, the part design must consider: a) the selected manufacturing process and its limitations, b) equipment and tooling requirements, c) process capabilities such as size, geometry, tolerances, and production rate, and d) properties of the incoming material under processing conditions. Often the design requires development of a new tooling andlor modification of an existing process. In such cases dielmold development and try-out can take as long or even longer that the time needed for die manufacturing. The assembly ready part geometry, usually in electronic form, must be used to develop the die or mold geometries as well as to select the process parameters. Figure 4 illustrates, using forging as an example, the flow of information and activities in computer aided die and process design Ill. Processes such as stamping, hot and cold forging may require several operations starting with the initial simple billet or sheet blank until the finish formed part is obtained. Thus, several die sets may be needed. In processes, where the incoming material is shapeless, e.g. powder compaction, injection molding, die casting, a single set of dies or molds have to be designed. Die design is essentially an experience-based activity. However, it is enhanced significantly by utilizing process modeling techniques to: 1. Estimate material flow and die stresses. 2. Establish optimum process parameters (machine and ram speed, dielmold and material temperatures, time for holding under pressure, etc.). 3. Design dielmold features, necessary to perform the process (flash and draft in forging, binder surface and draw beads in stamping, gates and runners in injection molding and die casting). 4. Finalize the product and die dimensions by predicting and eliminating defects while adjusting the process parameters for obtaining a robust process. The application of process modeling, using 3D-FEM based software, is now considered routine in (i) permanent mold and die casting, (ii) injection, gas injection, compression and blow molding, and (iii) sheet metal forming. In forging, while 2D simulation is widely practiced, 3D applications are being introduced by advanced technology companies. Research is being conducted on a “reverse simulation approach” for designing forging preforms 12. Examples of FEM simulation results are seen in Figure 5 for forging and Figure 6 for stamping Ill. Application of 2D-FEM simulation in metal cutting is now being introduced by many companies but it is still in the RBD stage. Most probably this application will be widely accepted during the next two to four years and also expanded to full 3D simulations of the metal cutting operations. Before they can be applied in the industrial environment, process simulation must be further developed for (a) forming of composite polymers (in mold lamination, compression molding of glass fiber reinforced polymeric composites) and b) sandwich sheet metal materials. Characterization of composite materials and formulation of the deformation laws represent considerable technical challenges and are still in the development stage. 3 PROTOTYPING AND RAPID TOOLING 3.1 Additive Manufacturing and Rapid Prototyping for Die and Mold Production The class of additive fabrication methods usually known as “rapid prototyping” (RP) or “solid freeform fabrication” (SFF) processes have evolved considerably over the past decade. Although they were originally marketed as aids to design visualization and prototyping, in recent years the most promising application of these technologies has been in the area of rapid tooling for net shape processes. An excellent review was given as a ClRP keynote paper at the 48th General Assembly 13. All of the processes currently in use follow the same basic sequence of steps to construct a component. The process begins with a CAD solid model of either a piece part or tool insert, which is typically transferred to the RP machine in STL format. This data structure reduces the solid model to a set of triangular facets that define the surfaces of the part. This STL file is then “sliced” by the machine controller software, turning what was originally a three- dimensional object into an ordered set of two-dimensional layers. The part is then reconstructed, one layer at a time 41. (b) BHF= 30 tons (wrinkles are eliminated) Figure 6: Example of FEM simulation in stamping. By optimizing the Blank Holder Force (BHF) control, it is possible to form a wrinkle-free part I I. The RP processes differ in the particular method used to form the build material, as well as in the build material itself. To date, the most common build materials are either a liquid (stereolithography), an extruded solid (fused Figure 4: Flow chart for product, die and process design deposition modeling) or a powder (selective laser sintering). The techniques used to shape the raw material typically use laser-activated chemical change (stereolithography), laser sintering (LENS, SLS), extrusion (FDM), or an adhesive binder (3D printing). 3.2 Design and Visualization Tools: New Developments A major thrust in the RP market has been the development of low-cost “3D printers”, which are designed for office use, and are intended solely as visualization aids to part designers. All of these processes are intended as low-cost prototyping methods for producing relatively fragile parts, allowing part designers to produce several iterations of a design quickly, and at low cost. None of these processes are presently capable of producing parts able to withstand significant stresses. 3.3 Rapid Production of Tooling Rapid production of dies and molds using additive processes can reduce the time and cost of bringing new products to market by drastically cutting down on design iterations and prototyping cycles. The additive processes (Example: Forging) I I. Figure 5: Simulation of forging an automotive crankshaft using a 3D commercial FEM code I I. have other advantages as well, such as the ability to build conformal cooling lines around a mold cavity, and the ability of some systems to tailor the material properties of the part as it is built. The concept of “rapid tooling” includes three distinct segments: prototype tooling, “bridge” tooling, and tooling for limited production runs. Prototype tooling is exactly what the name implies: a die or mold designed to test a new component design, a new material, or perhaps a new process. In this case the tool itself is not intended to produce more than a few hundred parts, so tool life, cycle time, and part ejection are typically not design issues. Much slower cycle times and manual ejection are often employed to simplify the tool design and save valuable time and producing the prototype tool. Because the cost of prototype tooling can be folded into the total tooling cost and amortized over the entire product life of the final product, cost is not a primary concern. On the other hand, product development constraints demand that the time to produce the tool must be very short, typically only a few days or weeks. “Bridge tooling” is the name applied to dies and molds that are designed to last for perhaps tens of thousands of product cycles. These tools permit a new product to come onto the market early, while the production tooling is still being fabricated. While these tools do not require the durability of production tools, and may not be optimized in terms of the process parameters, they must be able to withstand several thousand cycles, while holding production-level tolerances. Again, the cost of these tools can be folded into the total tooling cost for the entire production run. Finally, the most demanding application is for tools for short production runs. With the advent of lean manufacturing and mass customization, the need to produce tools that can produce quality parts in small quantities, and do so cost effectively, has become a major issue in many industries. Often it is unclear whether is it better to build a single die or mold to produce a limited number of parts, spread over several years, or is it better to build cheape