【溫馨提示】====【1】設(shè)計(jì)包含CAD圖紙 和 DOC文檔，均可以在線預(yù)覽，所見即所得，，dwg后綴的文件為CAD圖，超高清，可編輯，無任何水印，，充值下載得到【資源目錄】里展示的所有文件======【2】若題目上備注三維，則表示文件里包含三維源文件，由于三維組成零件數(shù)量較多，為保證預(yù)覽的簡潔性，店家將三維文件夾進(jìn)行了打包。三維預(yù)覽圖，均為店主電腦打開軟件進(jìn)行截圖的，保證能夠打開，下載后解壓即可。======【3】特價(jià)促銷，，拼團(tuán)購買，，均有不同程度的打折優(yōu)惠，，詳情可咨詢QQ：1304139763 或者 414951605======【4】 題目最后的備注【JA系列】為店主整理分類的代號(hào)，與課題內(nèi)容無關(guān)，請(qǐng)忽視
編號(hào)：
畢業(yè)設(shè)計(jì)(論文)開題報(bào)告
題 目： 筆蓋注塑模具設(shè)計(jì)
院 （系）： 國防生學(xué)院
專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
學(xué)生姓名： 盧衛(wèi)
學(xué) 號(hào)： 1000110107
指導(dǎo)教師單位： 機(jī)電工程學(xué)院
姓 名： 曹 泰 山
職 稱： 講 師
題目類型：¨理論研究 ¨實(shí)驗(yàn)研究 t工程設(shè)計(jì) ¨工程技術(shù)研究 ¨軟件開發(fā)
2013年12月23日
1．畢業(yè)設(shè)計(jì)的主要內(nèi)容、重點(diǎn)和難點(diǎn)等
畢業(yè)設(shè)計(jì)的主要內(nèi)容：
近年來，中國塑料模具發(fā)展速度相當(dāng)快。注塑模市場得到了很大的發(fā)展，市場競爭也越發(fā)激烈。為了做到高質(zhì)高效低成本來提高市場占有率,注塑模具的開發(fā)、設(shè)計(jì)與加工結(jié)合CAD/CAE/CAM技術(shù)具有重大意義。模具生產(chǎn)技術(shù)水平的高低已成為衡量一個(gè)國家產(chǎn)品制造水平高低的重要標(biāo)志，其主要內(nèi)容如下：
1、參觀調(diào)研，查閱資料。到模具制造相關(guān)企業(yè)調(diào)研，了解模具設(shè)計(jì)、生產(chǎn)、制造及加工情況。結(jié)合本次畢設(shè)課題，查閱模具相關(guān)資料；
2、 撰寫開題報(bào)告；
3、通過對(duì)產(chǎn)品的性能分析，完成相關(guān)的模具結(jié)構(gòu)與零件設(shè)計(jì)；
4、設(shè)計(jì)的模具結(jié)構(gòu)要求完整、合理；
5、合理選擇尺寸、公差、表面粗糙度和制件材料，繪制的產(chǎn)品圖樣完整；
6、認(rèn)真分析制件圖，確定模具型腔、模具結(jié)構(gòu)、分型面和進(jìn)料口形式，計(jì)算含收縮率的相關(guān)尺寸和模具的強(qiáng)度和剛度；
7、 翻譯專業(yè)外語文獻(xiàn)。
8、 撰寫畢業(yè)設(shè)計(jì)（論文）說明書；
9、 繪制模具總裝圖、零件圖；
畢業(yè)設(shè)計(jì)的重點(diǎn)難點(diǎn)：
1、塑件的合理性設(shè)計(jì)及結(jié)構(gòu)工藝性分析；
2、材料選擇，收縮率計(jì)算。模具強(qiáng)度及剛度分析；
3、塑件壁厚成型工藝考慮及保證塑件的外觀要求；
4、模具型腔數(shù)的確定，模具結(jié)構(gòu)、分型面和進(jìn)料口形式的選擇；
5、保證塑件成型時(shí)無變形，注出的制件表面光滑，無氣泡和其它缺陷，無飛邊或少飛邊。
6、繪制模具總裝圖、零件圖及尺寸標(biāo)注。
2．準(zhǔn)備情況（查閱的文獻(xiàn)資料及調(diào)研情況、現(xiàn)有設(shè)備、實(shí)驗(yàn)條件等）
模具工業(yè)是國民經(jīng)濟(jì)的重要基礎(chǔ)工業(yè)之一。模具是工業(yè)生產(chǎn)中的基礎(chǔ)工藝裝備，是一種高附加值的高精密集型產(chǎn)品，也是高新技術(shù)產(chǎn)業(yè)化的重要領(lǐng)域，其技術(shù)水平的高低已經(jīng)成為衡量一個(gè)國家制造業(yè)水平的重要標(biāo)志
專家預(yù)測，大型、精密、設(shè)計(jì)合理的注塑模具將受到市場普遍歡迎。通過調(diào)研及查閱資料,對(duì)側(cè)抽芯液壓錐螺紋接頭三通管注塑模設(shè)計(jì)方案有了初步的構(gòu)思。
調(diào)研情況
1.模具技術(shù)的現(xiàn)狀
20世紀(jì)80年代以來，國民經(jīng)濟(jì)的高速發(fā)展對(duì)模具工業(yè)提出了越來越高的要求，同時(shí)為模具的發(fā)展提供了巨大的動(dòng)力。這些年來，中國模具發(fā)展十分迅速，模具工業(yè)一直以15% 左右的增長速度快速發(fā)展。振興和發(fā)展中國的模具工業(yè)，日益受到人們的重視和關(guān)注。“模具是工業(yè)生產(chǎn)的基礎(chǔ)工藝裝備”已經(jīng)取得了共識(shí)。目前，中國有17000多個(gè)模具生產(chǎn)廠點(diǎn)，從業(yè)人數(shù)約50多萬。在模具工業(yè)的總產(chǎn)值中，沖壓模具約占50%，塑料模具約占33%，壓鑄模具約占6%，其他各類模具約占11%。近年來，中國模具工業(yè)企業(yè)的所有制成分也發(fā)生了變化。除了國有專業(yè)廠家外，還有集體企業(yè)、合資企業(yè)、獨(dú)資企業(yè)和私營企業(yè)，他們都得到了迅速的發(fā)展。許多模具企業(yè)十分重視技術(shù)發(fā)展。加大了用于技術(shù)進(jìn)步的投入力度，將技術(shù)進(jìn)步作為企業(yè)發(fā)展的重要?jiǎng)恿?。此外，許多研究機(jī)構(gòu)和大專院校也開展了模具技術(shù)的研究與開發(fā)。
中國塑料模工業(yè)從起步到現(xiàn)在，歷經(jīng)半個(gè)多世紀(jì)，有了很大發(fā)展，模具水平有了較大提高。在大型模具方面已能生產(chǎn)48in（約122cm）大屏幕彩電塑殼注射模具、6.5kg大容量洗衣機(jī)全套塑料模具以及汽車保險(xiǎn)杠和整體儀表板等塑料模具，精密塑料模具方面，已能生產(chǎn)照相機(jī)塑料件模具、多型腔小模數(shù)齒輪模具及塑封模具。經(jīng)過多年的努力，在模具CAD/ CAE/CAM技術(shù)、模具的電加工和數(shù)控加工技術(shù)、快速成型與快速制模技術(shù)、新型模具材料[1]等方面取得了顯著進(jìn)步；在提高模具質(zhì)量和縮短模具設(shè)計(jì)制造周期等方面作出了貢獻(xiàn)。
進(jìn)入21世紀(jì)，在經(jīng)濟(jì)全球化的新形勢下，隨著資本、技術(shù)和勞動(dòng)力市場的重新整合，中國裝備制造業(yè)在加入WTO以后，將成為世界裝備制造業(yè)的基地。而在現(xiàn)代制造業(yè)中，無論哪一行業(yè)的工程裝備，都越來越多地采用由模具工業(yè)提供的產(chǎn)品。為了適應(yīng)用戶對(duì)模具制造的高精度、短交貨期、低成本的迫切要求，模具工業(yè)正廣泛應(yīng)用現(xiàn)代先進(jìn)制造技術(shù)來加速模具工業(yè)的技術(shù)進(jìn)步，這是各行各業(yè)對(duì)模具這一基礎(chǔ)工藝裝備的迫切需求。
2.側(cè)抽芯筆蓋注塑模具設(shè)計(jì)的流程：
(1)思考與創(chuàng)新：繪制草圖，確定筆蓋外觀形式；
(2)實(shí)踐操作：通過Pro-e軟件畫出其三維模型；
(3)用Pro-e做出內(nèi)部的結(jié)構(gòu)，實(shí)現(xiàn)外觀要求；
(4)將Pro-e做的圖導(dǎo)入AutoCAD中；
(5)修改結(jié)構(gòu)圖。
3.注射模具的設(shè)計(jì)過程
(1)對(duì)塑料零件的材料、形狀和功能進(jìn)行分析
(2)確定型腔的數(shù)目
確定型腔的數(shù)目條件有：最大注射量、鎖模力、產(chǎn)品的精度要求和經(jīng)濟(jì)性等。
(3)選擇分型面
分型面的選擇應(yīng)以模具結(jié)構(gòu)簡單、分型容易，且不破壞已成型的塑件為原則。
(4)型腔的布置方案
型腔的布置應(yīng)采用平衡式排列，以保證各型腔平衡進(jìn)料。型腔的布置還要注意與冷卻管道、推桿布置的協(xié)調(diào)問題。
(5)確定澆注系統(tǒng)
澆注系統(tǒng)包括主流道、分流道、澆口和冷料穴。澆注系統(tǒng)的設(shè)計(jì)應(yīng)根據(jù)模具的類型、型腔的數(shù)目及布置方式、塑件的原料及尺寸等確定。
(6)確定脫模方式
脫模方式的設(shè)計(jì)應(yīng)根據(jù)塑件留在模具的部分而同。由于注射機(jī)的推出頂桿在動(dòng)模部分，所以，脫模推出機(jī)構(gòu)一般都設(shè)計(jì)在模具的動(dòng)模部分。因此，應(yīng)設(shè)計(jì)成使塑件能留在動(dòng)模部分。設(shè)計(jì)中，除了將較長的型芯安排在動(dòng)模部分以外，還常設(shè)計(jì)拉料桿，強(qiáng)制塑件留在動(dòng)模部分。但也有些塑件的結(jié)構(gòu)要求塑件在分型時(shí)，留在定模部分，在定模一側(cè)設(shè)計(jì)出推出裝置。推出機(jī)構(gòu)的設(shè)計(jì)也應(yīng)根據(jù)塑件的不同結(jié)構(gòu)設(shè)計(jì)出不同的形式，有推桿、推管和推板等結(jié)構(gòu)。
(7)確定調(diào)溫系統(tǒng)結(jié)構(gòu)
模具的調(diào)溫系統(tǒng)主要由塑料種類決定。模具的大小、塑件的物理性能、外觀和尺寸精度都對(duì)模具的調(diào)溫系統(tǒng)有影響。
(8)確定凹模和型心的固定方式
當(dāng)凹模或型心采用鑲塊結(jié)構(gòu)時(shí)，應(yīng)合理地劃分鐵塊并同時(shí)考慮鑲塊的強(qiáng)度、可加工性及安裝固定。
(9)確定排氣尺寸
一般注射模的排氣可以利用模具分型面和推桿與模具的間隙；而對(duì)于大型和高速成型的注射模，必須設(shè)計(jì)相應(yīng)的排氣裝置。
(10)確定注射模的主要尺寸
根據(jù)相應(yīng)的公式，計(jì)算成型零件的工作尺寸，以及決定模具型腔的側(cè)壁厚度、動(dòng)模板的厚度、拼塊式型腔的型腔板的厚度及注射模的閉合高度。
(11)選用標(biāo)準(zhǔn)模架
根據(jù)設(shè)計(jì)、計(jì)算的注射模的主要尺寸，來選用注視模的標(biāo)準(zhǔn)模架，并盡量選擇標(biāo)準(zhǔn)模具零件。
(12)繪制模具的結(jié)構(gòu)草圖
在以上工作的基礎(chǔ)上，繪制注射模的完整的結(jié)構(gòu)草圖，繪制模具結(jié)構(gòu)圖是模具設(shè)計(jì)十分重要的工作，其步驟為先畫俯視圖（順序?yàn)椋寒嬆＜堋⑿颓?、冷卻管道、支撐柱、推出機(jī)構(gòu)），再畫出主視圖。
(13)校核模具與注射機(jī)有關(guān)尺寸
對(duì)所使用的注射機(jī)的參數(shù)進(jìn)行校核：包括最大注射量、注射壓力、鎖模力及模具的安裝部分的尺寸、開模行程和推出機(jī)構(gòu)的校核。
(14)注射模結(jié)構(gòu)設(shè)計(jì)的審查
對(duì)根據(jù)上述有關(guān)注視模結(jié)構(gòu)設(shè)計(jì)的各項(xiàng)要求設(shè)計(jì)出來的注射模，應(yīng)進(jìn)行注射模結(jié)構(gòu)設(shè)計(jì)的初步審查，同時(shí)，也有必要對(duì)提出的要求加以確認(rèn)和修改。
(15)繪制模具的裝配圖
裝配圖是模具裝配的主要依據(jù)，因此應(yīng)清楚地表明注視模的各個(gè)零件的裝配關(guān)系、必要的尺寸（如外形尺寸、定位圈直徑、安裝尺寸、活動(dòng)零件的極限尺寸等）、序號(hào)、明細(xì)表、標(biāo)題欄及技術(shù)要求。
(16)繪制模具的零件圖
由模具裝配圖拆繪零件圖的順序?yàn)椋合葍?nèi)后外，先復(fù)雜后簡單，先成型零件后結(jié)構(gòu)零件。
(17)復(fù)核設(shè)計(jì)圖樣
注射模具設(shè)計(jì)的最后是審核所設(shè)計(jì)的注射模，應(yīng)多關(guān)注零件的加工、性能。
已查閱的文獻(xiàn)資料
[1] 屈華昌.塑料成型工藝與模具設(shè)計(jì)[M].北京：高等教育出版社，2007.
[2] 宋長發(fā).工程制圖[M].北京：國防工業(yè)出版社，2011.
[3] 任仲貴. CAD/CAM原理[M]. 北京：清華大學(xué)出版社，1991.
[4] 王明強(qiáng). 計(jì)算機(jī)輔助設(shè)計(jì)技術(shù)[M]. 北京：科學(xué)出版社，2002.
[5] 許鶴峰.注射模具設(shè)計(jì)要點(diǎn)與圖例[M].北京：化學(xué)工業(yè)出版社，1999.
[6] 李名堯.模具CAD/CAM[M].北京：機(jī)械工業(yè)出版社，2004.
[7] 潘寶權(quán).模具制造工藝[M].北京;機(jī)械工業(yè)出版社，2004.
[8] 張維合.注塑模具設(shè)計(jì)實(shí)用教程[M].北京:化學(xué)工業(yè)出版社,2007.9.
[9] 李學(xué)鋒. 塑料模設(shè)計(jì)及制造[M].北京:機(jī)械工業(yè)出版社,2002.6
[10] Y. Zhang, W. Hu and Y. Rong et al. Graph-based set-up planning and tolerance decomposition for computer-aided fixture design. International Journal of Production Research [J], 2001, 39(14): 3109-3126.
現(xiàn)有設(shè)備及實(shí)驗(yàn)條件：計(jì)算機(jī)一臺(tái)，使用軟件為Pro/Engineer5.0及Auto CAD2008、Moldflow insight，以上實(shí)驗(yàn)條件可滿足本次畢業(yè)設(shè)計(jì)的要求。
3、實(shí)施方案、進(jìn)度實(shí)施計(jì)劃及預(yù)期提交的畢業(yè)設(shè)計(jì)資料
一、2013年12月9日至2013年12月22日，理解消化畢設(shè)任務(wù)書要求并收集、分析、消化資料文獻(xiàn)，根據(jù)畢設(shè)內(nèi)容完成并交開題報(bào)告；
二、2014年1月6日至2014年1月13日，開展調(diào)研，了解塑件結(jié)構(gòu)，對(duì)原材料進(jìn)行分析，考慮塑件的成型工藝性、模具的總體結(jié)構(gòu)的形式，并完成部分英文摘要翻譯。
三、2014年3月4日至2013年3月31日，查閱資料，熟悉注射模的結(jié)構(gòu)及有關(guān)計(jì)算，擬定模具的方案設(shè)計(jì)、總體設(shè)計(jì)及主要零件設(shè)計(jì)，擬定成型工藝過程，查閱有關(guān)手冊(cè)確定適宜的工藝參數(shù)，注射機(jī)的選擇及確定注射設(shè)備及型號(hào)規(guī)格；
四、2014年4月1日至2014年4月6日，完成設(shè)計(jì)計(jì)算任務(wù)，總體結(jié)構(gòu)的設(shè)計(jì)和完成總裝配圖及零件圖的設(shè)計(jì)；
五、2014年4月7日至2014年4月21日，完成設(shè)計(jì)，圖紙繪制任務(wù)，工藝規(guī)程說明書的編寫；
六、2014年4月22日至2014年5月4日，完善設(shè)計(jì)并完成論文的撰寫；
七、2014年5月5日至2014年5月9日，修改并打印畢業(yè)論文及整理相關(guān)資料，交指導(dǎo)老師評(píng)閱，準(zhǔn)備論文答辯。
指導(dǎo)教師意見
指導(dǎo)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
編號(hào)：
畢業(yè)設(shè)計(jì)(論文)任務(wù)書
題 目： 筆蓋注塑模具設(shè)計(jì)
學(xué) 院： 國防生學(xué)院
專 業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
學(xué)生姓名： 盧 衛(wèi)
學(xué) 號(hào)： 1000110107
指導(dǎo)教師單位： 機(jī)電工程學(xué)院
姓 名： 曹泰山
職 稱： 講師
題目類型：¨理論研究 ¨實(shí)驗(yàn)研究 t工程設(shè)計(jì) ¨工程技術(shù)研究 ¨軟件開發(fā)
2013年12月9日
一、畢業(yè)設(shè)計(jì)（論文）的內(nèi)容
畢業(yè)設(shè)計(jì)內(nèi)容
1、查找相關(guān)的資料并閱讀消化，明確筆蓋注塑模具設(shè)計(jì)要求，分析該塑料制品成型工藝及其可能性和經(jīng)濟(jì)性等因素，對(duì)零件圖紙進(jìn)行結(jié)構(gòu)和工藝分析，設(shè)計(jì)成型工藝；
2、掌握成型設(shè)備的技術(shù)規(guī)范，進(jìn)行模具結(jié)構(gòu)設(shè)計(jì)及模具設(shè)計(jì)的有關(guān)計(jì)算；
3、模具總體尺寸的設(shè)計(jì)與結(jié)構(gòu)草圖的繪制，模具結(jié)構(gòu)總裝圖和零件工作圖的設(shè)計(jì)繪制；
4、編制主要零件的制造工藝。
二、畢業(yè)設(shè)計(jì)（論文）的要求與數(shù)據(jù)
1、筆蓋形狀特點(diǎn)確定其注塑模的方案設(shè)計(jì)；
2、該塑料制品的設(shè)計(jì)難點(diǎn)是抽芯機(jī)構(gòu)的設(shè)計(jì)；
3、確定其使用的材料為塑料；
4、制品的具體尺寸請(qǐng)測繪出圖；
5、塑件成型時(shí)無變形，注出的制件表面光滑，無氣泡和其它缺陷，無飛邊或少飛邊。
三、畢業(yè)設(shè)計(jì)（論文）應(yīng)完成的工作
1、完成注塑模的總體方案設(shè)計(jì)，完成開題報(bào)告。
2、進(jìn)行模具結(jié)構(gòu)設(shè)計(jì)并選用標(biāo)準(zhǔn)件，完成零件間的配給選用及相關(guān)的設(shè)計(jì)計(jì)算。
3、用A0圖紙繪制裝配圖，采用CAD軟件繪制零件圖，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(jì)算機(jī)繪圖圖紙，用PRO/E 軟件對(duì)塑件和模具進(jìn)行實(shí)體造型。
4、完成二萬字左右的畢業(yè)設(shè)計(jì)說明書（論文）；在畢業(yè)設(shè)計(jì)說明書（論文）中必須包括300-500個(gè)單詞詳細(xì)的英文摘要；
5、獨(dú)立完成與課題相關(guān)，不少于四萬字符的指定英文資料翻譯（附英文原文）；
6、完成導(dǎo)師所指定的其它工作。并附有開題報(bào)告一份。
四、應(yīng)收集的資料及主要參考文獻(xiàn)
[1] 屈華昌.塑料成型工藝與模具設(shè)計(jì)[M].北京:機(jī)械工業(yè)出版社，2002.
[2] 模具實(shí)用技術(shù)叢書編委會(huì)．模具實(shí)用技術(shù)注塑模具設(shè)計(jì)制造與應(yīng)用實(shí)例[M]．北京:機(jī)械工業(yè)出版社，2002.
[3] 顏智偉.塑料模具設(shè)計(jì)與機(jī)構(gòu)設(shè)計(jì)[M].北京：國防工業(yè)出版社，2006.
[4] 姜明艷.薄壁外殼注塑模設(shè)計(jì)[J]. 北京：機(jī)械工業(yè)出版社，2002.
[5] 王文廣等.塑料注射模具設(shè)計(jì)技巧與實(shí)例[M].北京：化學(xué)工業(yè)出版社.2004.
[6] 模具實(shí)用技術(shù)叢書編委會(huì)編.塑料模具設(shè)計(jì)制造與應(yīng)用實(shí)例[M].北京：機(jī)械工業(yè)出版社.2002.
[7] 李學(xué)鋒.塑料模設(shè)計(jì)及制造[M].北京：機(jī)械工業(yè)出版社 2002.
[8]〔德〕G.曼格斯，李玉泉譯.塑料注射成型模具的設(shè)計(jì)和制造[M].北京輕工出版社,2005.
[9]譚雪松, 林曉新, 溫麗編. 新編塑料模具設(shè)計(jì)手冊(cè)[M].北京：人民郵電出版社，2007.
[10] Childs Peter R.N．Mechanical Design[J]．Oxford :Butterworth-Heinemann，2003
五、試驗(yàn)、測試、試制加工所需主要儀器設(shè)備及條件
計(jì)算機(jī)一臺(tái)
CAD設(shè)計(jì)軟件
任務(wù)下達(dá)時(shí)間：
2013年12月9日
畢業(yè)設(shè)計(jì)開始與完成時(shí)間：
2013年12月17日至 2014年05 月4日
組織實(shí)施單位：
教研室主任意見：
簽字： 2013年12月14日
院領(lǐng)導(dǎo)小組意見：
簽字： 2013 年12月16日
2014年機(jī)電工程學(xué)院畢業(yè)設(shè)計(jì)(論文)進(jìn)度計(jì)劃表
學(xué)生姓名：盧衛(wèi) 學(xué)號(hào)：1000110107
序號(hào)
起止日期
計(jì)劃完成內(nèi)容
實(shí)際完成內(nèi)容
檢查日期
檢查人簽名
1
2013.12.17—12.23
教師填寫，下同
教師填寫，下同
2
2013.12.24—12.30
3
2013.12.31-2014.1.6
4
2014.1.7-1.13
5
3.4-3.10
6
3.11-3.17
7
3.18-3.24
8
3.25-3.31
(本表同時(shí)作為指導(dǎo)教師對(duì)學(xué)生的16次考勤記錄)
2014年機(jī)電工程學(xué)院畢業(yè)設(shè)計(jì)進(jìn)度計(jì)劃表（續(xù)）
學(xué)生姓名： 學(xué)號(hào)：
序號(hào)
起止日期
計(jì)劃完成內(nèi)容
實(shí)際完成內(nèi)容
檢查日期
檢查人簽名
9
4.01-4.07
教師填寫，下同
教師填寫，下同
10
4.08-4.14
11
4.15-4.21
12
4.22-4.28
13
4.29-5.05
14
5.06-5.12
15
5.13-5.19
16
5.20-5.26
完成畢業(yè)設(shè)計(jì)，提交論文
任務(wù)下達(dá)時(shí)間：2013年12月17日 (本表同時(shí)作為指導(dǎo)教師對(duì)學(xué)生的16次考勤記錄)
第 2 頁 共 2 頁
畢業(yè)設(shè)計(jì)（論文）中期檢查表（指導(dǎo)教師）
指導(dǎo)教師姓名：曹泰山 填表日期： 2014年 4 月 20 日
學(xué)生學(xué)號(hào)
1000110107
學(xué)生姓名
盧衛(wèi)
題目名稱
筆蓋注塑模具設(shè)計(jì)
已完成內(nèi)容
1、完成裝配圖的繪制；
2、完成大部分論文；
3、完成英文翻譯；
4、大部分零件圖的繪制；
檢查日期：2014-4-20
完成情況
t全部完成
□按進(jìn)度完成
□滯后進(jìn)度安排
存在困難
相關(guān)部分的計(jì)算比較難進(jìn)行。
解決辦法
查閱相關(guān)資料，并且與指導(dǎo)老師和同學(xué)們一起討論解決方案。
預(yù)期成績
□優(yōu) 秀
t良 好
□中 等
□及 格
□不及格
建
議
教師簽名：
教務(wù)處實(shí)踐教學(xué)科制表
說明：1、本表由檢查畢業(yè)設(shè)計(jì)的指導(dǎo)教師如實(shí)填寫；2、此表要放入畢業(yè)設(shè)計(jì)（論文）檔案袋中；
3、各院(系)分類匯總后報(bào)教務(wù)處實(shí)踐教學(xué)科備案
桂林電子科技大學(xué)畢業(yè)設(shè)計(jì)（論文）說明書用紙
An Analysis of Draw-Wall Wrinkling in a Stamping Die Design
F.-K. Chen and Y.-C. Liao
Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan
Wrinkling that occurs in the stamping of tapered square cups and stepped rectangular cups is investigated. A common characteristic of these two types of wrinkling is that the wrinkles are found at the draw wall that is relatively unsupported.In the stamping of a tapered square cup, the effect of process parameters, such as the die gap and blank-holder force, on the occurrence of wrinkling is examined using finiteelement simulations. The simulation results show that the larger the die gap, the more severe is the wrinkling, and such wrinkling cannot be suppressed by increasing the blank-holder force. In the analysis of wrinkling that occurred in the stamping of a stepped rectangular cup, an actual production part that has a similar type of geometry was examined. The wrinkles found at the draw wall are attributed to the unbalanced stretching of the sheet metal between the punch head and the step edge. An optimum die design for the purpose of eliminating the wrinkles is determined using finite-element analysis. The good agreement between the simulation results and those observed in the wrinkle-free production part validates the accuracy of the finite-element analysis, and demonstrates the advantage of using finite-element analysis for stamping die design.
Keywords: Draw-wall wrinkle; Stamping die; Stepped rectangular cup; Tapered square cups
1. Introduction
Wrinkling is one of the major defects that occur in the sheet metal forming process. For both functional and visual reasons,wrinkles are usually not acceptable in a finished part. There are three types of wrinkle which frequently occur in the sheet metal forming process: flange wrinkling, wall wrinkling, and elastic buckling of the undeformed area owing to residual elastic compressive stresses. In the forming operation of stamping a complex shape, draw-wall wrinkling means the occurrence of wrinkles in the die cavity. Since the sheet metal in the wall area is relatively unsupported by the tool, the elimination of wall wrinkles is more difficult than the suppression of flange wrinkles. It is well known that additional stretching of the material in the unsupported wall area may prevent wrinkling,and this can be achieved in practice by increasing the blankholder force; but the application of excessive tensile stresses leads to failure by tearing. Hence, the blank-holder force must lie within a narrow range, above that necessary to suppress wrinkles on the one hand, and below that which produces fracture on the other. This narrow range of blank-holder force is difficult to determine. For wrinkles occurring in the central area of a stamped part with a complex shape, a workable range of blank-holder force does not even exist.
In order to examine the mechanics of the formation of wrinkles, Yoshida et al. [1] developed a test in which a thin plate was non-uniformly stretched along one of its diagonals.They also proposed an approximate theoretical model in which the onset of wrinkling is due to elastic buckling resulting from the compressive lateral stresses developed in the non-uniform stress field. Yu et al. [2,3] investigated the wrinkling problem both experimentally and analytically. They found that wrinkling could occur having two circumferential waves according to their theoretical analysis, whereas the experimental results indicated four to six wrinkles. Narayanasamy and Sowerby [4]
examined the wrinkling of sheet metal when drawing it through a conical die using flat-bottomed and hemispherical-ended punches. They also attempted to rank the properties that appeared to suppress wrinkling.
These efforts are focused on the wrinkling problems associated with the forming operations of simple shapes only, such as a circular cup. In the early 1990s, the successful application of the 3D dynamic/explicit finite-element method to the sheetmetal forming process made it possible to analyse the wrinkling problem involved in stamping complex shapes. In the present study, the 3D finite-element method was employed to analyse the effects of the process parameters on the metal flow causing wrinkles at the draw wall in the stamping of a tapered square cup, and of a stepped rectangular part.
A tapered square cup, as shown in Fig. 1(a), has an inclined draw wall on each side of the cup, similar to that existing in a conical cup. During the stamping process, the sheet metal on the draw wall is relatively unsupported, and is therefore prone to wrinkling. In the present study, the effect of various process parameters on the wrinkling was investigated. In the case of a stepped rectangular part, as shown in Fig. 1(b),another type of wrinkling is observed. In order to estimate the effectiveness of the analysis, an actual production part with stepped geometry was examined in the present study. The cause of the wrinkling was determined using finite-element analysis, and an optimum die design was proposed to eliminate the wrinkles. The die design obtained from finite-element analysis was validated by observations on an actual production part.
Sketches of (a) a tapered square cup.
Sketches of(b) a stepped rectangular cup.
Fig. 1.
2. Finite-Element Model
The tooling geometry, including the punch, die and blankholder,were designed using the CAD program PRO/ENGINEER. Both the 3-node and 4-node shell elements were adopted to generate the mesh systems for the above tooling using the same CAD program. For the finite-element simulation,the tooling is considered to be rigid, and the corresponding meshes are used only to define the tooling geometry and are not for stress analysis. The same CAD program using 4-node shell elements was employed to construct the mesh system for the sheet blank. Figure 2 shows the mesh system for the complete set of tooling and the sheet-blank used in the stamping of a tapered square cup. Owing to the symmetric conditions, only a quarter of the square cup is analysed. In the simulation, the sheet blank is put on the blank-holder and the die is moved down to clamp the sheet blank against the blank-holder. The punch is then moved up to draw the sheet metal into the die cavity.
In order to perform an accurate finite-element analysis, the actual stress–strain relationship of the sheet metal is required as part of the input data.In the present study, sheet metal with deep-drawing quality is used in the simulations.A tensile test has been conducted for the specimens cut along planes coinciding with the rolling direction (0°) and at angles of 45°and 90°to the rolling direction.The average flow stress σ,calculated from the equation σ=（σ0+2σ45+σ90）/4, for each measured true strain,as shown in Fig.3, is used for the simulations for the stampings of the tapered square cup and also for the stepped rectangular cup.
All the simulations performed in the present study were run on an SGI Indigo 2 workstation using the finite-element program PAMFSTAMP. To complete the set of input data required for the simulations, the punch speed is set to 10 m s_1 and a coefficient of Coulomb friction equal to 0.1 is assumed.
Fig. 2. Finite-element mesh.
Fig. 3. The stress–strain relationship for the sheet metal.
3. Wrinkling in a Tapered Square Cup
A sketch indicating some relevant dimensions of the tapered square cup is shown in Fig. 1(a). As seen in Fig. 1(a), the length of each side of the square punch head (2Wp), the die cavity opening (2Wd), and the drawing height (H) are considered as the crucial dimensions that affect the wrinkling.Half of the difference between the dimensions of the die cavity opening and the punch head is termed the die gap (G) in the present study, i.e. G = Wd-Wp. The extent of the relatively unsupported sheet metal at the draw wall is presumably due to the die gap, and the wrinkles are supposed to be suppressed by increasing the blank-holder force. The effects of both the die gap and the blank-holder force in relation to the occurrence of wrinkling in the stamping of a tapered square cup are investigated in the following sections.
3.1 Effect of Die Gap
In order to examine the effect of die gap on the wrinkling, the stamping of a tapered square cup with three different die gaps of 20 mm, 30 mm, and 50 mm was simulated. In each simulation, the die cavity opening is fixed at 200 mm, and the cup is drawn to the same height of 100 mm. The sheet metal used in all three simulations is a 380 mm × 380 mm square sheet with thickness of 0.7 mm, the stress–strain curve for the material is shown in Fig. 3.
Fig. 4. Wrinkling in a tapered square cup (G =50 mm).
The simulation results show that wrinkling occurred in all three tapered square cups, and the simulated shape of the drawn cup for a die gap of 50 mm is shown in Fig. 4. It is seen in Fig. 4 that the wrinkling is distributed on the draw wall and is particularly obvious at the corner between adjacent walls. It is suggested that the wrinkling is due to the large unsupported area at the draw wall during the stamping process,also,the side length of the punch head and the die cavity openingare different owing to the die gap. The sheet metal stretched between the punch head and the die cavity shoulder becomes unstable owing to the presence of compressive transverse stresses. The unconstrained stretching of the sheet metal under compression seems to be the main cause for the wrinkling at the draw wall. In order to compare the results for the three different die gaps, the ratio β of the two principal strains is introduced, β being εmin/εmax, where εmax and εmin are the major and the minor principal strains, respectively. Hosford and Caddell [5] have shown that if the absolute value of β is greater than a critical value, wrinkling is supposed to occur, and the larger the absolute value of β, the greater is the possibility of wrinkling.
The β values along the cross-section M–N at the same drawing height for the three simulated shapes with different die gaps, as marked in Fig. 4, are plotted in Fig. 5. It is noted from Fig. 5 that severe wrinkles are located close to the corner and fewer wrinkles occur in the middle of the draw wall for all three different die gaps. It is also noted that the bigger the die gap, the larger is the absolute value of β. Consequently,increasing the die gap will increase the possibility of wrinkling occurring at the draw wall of the tapered square cup.
3.2 Effect of the Blank-Holder Force
It is well known that increasing the blank-holder force can help to eliminate wrinkling in the stamping process. In order to study the effectiveness of increased blank-holder force, the stamping of a tapered square cup with die gap of 50 mm,which is associated with severe wrinkling as stated above, was simulated with different values of blank-holder force. The blank-holder force was increased from 100 kN to 600 kN,which yielded a blank-holder pressure of 0.33 MPa and 1.98 MPa, respectively. The remaining simulation conditions are maintained the same as those specified in the previous section.（An intermediate blank-holder force of 300 kN was also used in the simulation.）
The simulation results show that an increase in the blankholder force does not help to eliminate the wrinkling that occurs at the draw wall.The β values along the cross-section compared with one another for the stamping processes with blank-holder force of 100 kN and 600 kN. The simulation results indicate that the _ values along the cross-section M–N are almost identical in both cases. In order to examine the difference of the wrinkle shape for the two different blank-holder forces, five cross-sections of the draw wall at different heights from the bottom to the line M–N, as marked in Fig. 4, are plotted in Fig. 6 for both cases.It is noted from Fig. 6 that the waviness of the cross-sections for both cases is similar. This indicates that the blank-holder force does not affect the occurrence of wrinkling in the stamping of a tapered square cup, because the formation of wrinkles is mainly due to the large unsupported area at the draw wall where large compressive transverse stresses exist. The blankholder force has no influence on the instability mode of the material between the punch head and the die cavity shoulder.
Distance(mm)
Fig. 5. β-value along the cross-section M–N for different die gaps.
Fig. 6. Cross-section lines at different heights of the draw wall for
different blank-holder forces. (a) 100 kN. (b) 600 kN.
4. Stepped Rectangular Cup
In the stamping of a stepped rectangular cup, wrinkling occurs at the draw wall even though the die gaps are not so significant.Figure 1(b) shows a sketch of a punch shape used for stamping a stepped rectangular cup in which the draw wall C is followed by a step D–E. An actual production part that has this type of geometry was examined in the present study. The material used for this production part was 0.7 mm thick, and the stress–strain relation obtained from tensile tests is shown in Fig. 3.
The procedure in the press shop for the production of this stamping part consists of deep drawing followed by trimming.In the deep drawing process, no draw bead is employed on the die surface to facilitate the metal flow. However, owing to the small punch corner radius and complex geometry, a split occurred at the top edge of the punch and wrinkles were found to occur at the draw wall of the actual production part,as shown in Fig. 7. It is seen from Fig. 7 that wrinkles are distributed on the draw wall, but are more severe at the corner edges of the step, as marked by A–D and B–E in Fig. 1(b).The metal is torn apart along the whole top edge of the punch,as shown in Fig. 7, to form a split.
Fig. 7. Split and wrinkles in the production part.
Fig. 8. Simulated shape for the production part with split and wrinkles.
In order to provide a further understanding of the deformation of the sheet-blank during the stamping process, a finiteelement analysis was conducted. The finite-element simulation was first performed for the original design. The simulated shape of the part is shown from Fig. 8. It is noted from Fig.8 that the mesh at the top edge of the part is stretched significantly, and that wrinkles are distributed at the draw wall,similar to those observed in the actual part.The small punch radius, such as the radius along the edge A–B, and the radius of the punch corner A, as marked in Fig.1(b), are considered to be the major reasons for the wall breakage. However, according to the results of the finiteelement analysis, splitting can be avoided by increasing the above-mentioned radii. This concept was validated by the actual production part manufactured with larger corner radii.
Several attempts were also made to eliminate the wrinkling.First, the blank-holder force was increased to twice the original value. However, just as for the results obtained in the previous section for the drawing of tapered square cup, the effect of blank-holder force on the elimination of wrinkling was not found to be significant. The same results are also obtained by increasing the friction or increasing the blank size. We conclude that this kind of wrinkling cannot be suppressed by increasing the stretching force.
Since wrinkles are formed because of excessive metal flow in certain regions, where the sheet is subjected to large compressive stresses, a straightforward method of eliminating the wrinkles is to add drawbars in the wrinkled area to absorb the redundant material. The drawbars should be added parallel to the direction of the wrinkles so that the redundant metal can be absorbed effectively. Based on this concept, two drawbars are added to the adjacent walls, as shown in Fig. 9, to absorb the excessive material. The simulation results show that the wrinkles at the corner of the step are absorbed by the drawbars as expected, however some wrinkles still appear at the remaining wall. This indicates the need to put more drawbars at the draw wall to absorb all the excess material. This is, however,not permissible from considerations of the part design.
Fig. 9. Drawbars added to the draw walls.
One of the advantages of using finite-element analysis for the stamping process is that the deformed shape of the sheet blank can be monitored throughout the stamping process, which is not possible in the actual production process. A close look at the metal flow during the stamping process reveals that the sheet blank is first drawn into the die cavity by the punch head and the wrinkles are not formed until the sheet blank touches the step edge D–E marked in Fig. 1(b). The wrinkled shape is shown in Fig. 10. This provides valuable information for a possible modification of die design.
Fig. 10. Wrinkle formed when the sheet blank touches the steppededge.
Fig. 11. Cut-off of the stepped corner.
Fig. 12. Simulated shape for the modified die design.
An initial surmise for the cause of the occurrence of wrinkling is the uneven stretch of the sheet metal between the punch corner radius A and the step corner radius D, as indicated in Fig. 1(b). Therefore a modification of die design was carried out in which the step corner was cut off, as shown in Fig.11, so that the stretch condition is changed favourably, which allows more stretch to be applied by increasing the step edges.However, wrinkles were still found at the draw wall of the cup. This result implies that wrinkles are introduced because of the uneven stretch between the whole punch head edge and the whole step edge, not merely between the punch corner and the step corner. In order to verify this idea, two modifications of the die design were suggested: one is to cut the whole step off, and the other is to add one more drawing operation, that is, to draw the desired shape using two drawing operations.The simulated shape for the former method is shown in Fig.12. Since the lower step is cut off, the drawing process is quite similar to that of a rectangular cup drawing, as shown in Fig. 12. It is seen in Fig. 12 that the wrinkles were eliminated.
In the two-operation drawing process, the sheet blank was first drawn to the deeper step, as shown in Fig. 13(a). Subsequently,the lower step was formed in the second drawing operation, and the desired shape was then obtained, as shown in Fig. 13(b). It is seen clearly in Fig. 13(b) that the stepped rectangular cup can be manufactured without wrinkling, by a two-operation drawing process. It should also be noted that in the two-operation drawing process, if an opposite sequence is applied, that is, the lower step is formed first and is followed by the drawing of the deeper step, the edge of the deeper step,as shown by A–B in Fig. 1(b), is prone to tearing because the
metal cannot easily flow over the lower step into the die cavity.
The finite-element simulations have indicated that the die design for stamping the desired stepped rectangular cup using one single draw operation is barely achieved. However, the manufacturing cost is expected to be much higher for the twooperation drawing process owing to the additional die cost and operation cost. In order to maintain a lower manufacturing cost, the part design engineer made suitable shape changes, and modified the die design according to the finite-element
Simulation result to cut off the lower step, as shown in Fig.12. With the modified die design, the actual stamping die for production was manufactured and the production part was found to be free from wrinkles, as shown in Fig.14.The part shape also agreed well with that obtaine