喜歡這套資料就充值下載吧。。。資源目錄里展示的都可在線預覽哦。。。下載后都有，，請放心下載，，文件全都包含在內，，【有疑問咨詢QQ:1064457796 或 1304139763】
============================================喜歡這套資料就充值下載吧。。。資源目錄里展示的都可在線預覽哦。。。下載后都有，，請放心下載，，文件全都包含在內，，【有疑問咨詢QQ:1064457796 或 1304139763】
============================================
華東交通大學理工學院
畢業(yè)設計（論文）原創(chuàng)性聲明
本人鄭重聲明，所呈交的畢業(yè)設計（論文)是本人在導師的指導下獨立進行的研究工作所取得的研究成果。除了文中特別加以標注引用的內容外，本設計（論文）不包含法律意義上已屬于他人的任何形式的研究成果,也不包含本人已用于其他學位申請的論文或成果。對本文的研究作出重要貢獻的個人和集體，均已在文中以明確方式表明。本人完全意識到本聲明的法律后果由本人承擔。
作者簽名：曾智洋 日期：2010.5.23
畢業(yè)設計（論文）版權使用授權書
本畢業(yè)設計（論文）作者完全了解學校有關保留、使用畢業(yè)設計（論文）的規(guī)定，同意學校保留并向國家有關部門或機構送交設計（論文）的復印件和電子版，允許設計（論文）被查閱和借閱。本人授權華東交通大學理工學院可以將本設計（論文）的全部或部分內容編入有關數(shù)據(jù)庫進行檢索，可以采用影印、縮印或掃描等復制手段保存和匯編畢業(yè)設計（論文）。
作者簽名：曾智洋 日期：2010.5.23
導師簽名： 日期：
理工學院
本科生畢業(yè)設計（論文）開題報告
題 目：（罩殼）壓鑄模具設計____________
分 院：機電分院_______________________________
專 業(yè)：材料成型及控制工程__________________
班 級：材料（2）班____________________________
學 號：20060410210210_________________________
姓 名：曾智洋___________________________________
指導教師：莊文瑋___________________________________
填表日期：2010年03月23日
一．目的及意義
壓鑄是一種合金液在高壓作用下高速填充型腔，并在高壓下凝固形成鑄件的特殊鑄造方法，主要用于有色金屬，如鋅合金、鋁合金、鎂合金、銅合金等。其主要特點是高壓和高速，常用壓力為數(shù)十甚至上百兆帕，填充速度（內澆口速度）約為16～80米/秒，金屬液填充模具型腔的時間極短，約為0.01～0.2秒。作為一種少無切削的成形方法，壓鑄具有生產效率高，鑄件尺寸精度高，表面粗糙度好，經濟指標優(yōu)良的優(yōu)點，可以節(jié)省大量機加工工序和設備，節(jié)約原材料。在節(jié)能降耗，追求可持續(xù)發(fā)展的浪潮中，壓鑄在在制造業(yè)尤其是規(guī)?；a業(yè)獲得了廣泛的應用和迅速的發(fā)展。
就世界范圍而言，壓鑄業(yè)發(fā)展的主要推動力是汽車業(yè)的發(fā)展，這是由于汽車生產商追求整車輕量化的原因。由于鋁的質量比較輕，在汽車業(yè)中，鋁合金是應用最廣泛、發(fā)展最快的輕金屬。鋁合金在汽車工業(yè)中的應用以壓鑄為主要工藝，壓鑄占全部鑄造方法的 55％左右。我國鋁合金壓鑄件占主導地位，其應用范圍正在不斷擴大，年產量持續(xù)上升。過去，鋁合金鑄件多用于變速箱、汽缸頭、油泵、化油器等不受強烈沖擊的外殼。由于汽車需要更薄壁和更強韌的結構件，能夠熱處理和焊接的高品質壓鑄件的應用范圍也越來越大，采用鋁合金真空壓鑄的底盤結構件正在逐漸取代鋼鐵鑄件或鍛件。。
伴隨著汽車壓鑄件的功能和應用領域的不斷擴大，壓鑄業(yè)獲得了前所未有的發(fā)展機遇，市場競爭不斷加劇，壓鑄件正在向大型化、復雜化及高性能的方向發(fā)展。在這種情況下，必須不斷提高壓鑄件產品質量、降低生產成本，加速新品交付周期，才能提升企業(yè)的核心競爭力。壓鑄模設計在壓鑄生產中起著至關重要的作用，高新技術特別是計算機技術在壓鑄模設計中的應用明顯地提高了壓鑄設計質量，促進了壓鑄業(yè)的飛速發(fā)展。目前，壓鑄生產常用的計算機技術包括： CAD（計算機輔助壓鑄模設計技術）、CAE（計算機模擬分析技術）、CAM（計算機輔助制造技術）以及RPM（快速原型制造）等。這些技術是改造傳統(tǒng)生產方式的關鍵技術，它以計算機軟件的形式，為用戶提供多種有效的輔助工具，使工程技術人員能借助計算機對產品、模具結構、壓鑄工藝、數(shù)控加工及成本等進行設計和優(yōu)化。其中，CAD改變了壓鑄模設計中傳統(tǒng)的手工畫圖的模式，不僅能輕松完成復雜零件的壓鑄模設計，拓寬了壓鑄件的產品范圍，而且減輕了設計勞動強度，將設計人員從從繁冗的繪圖和計算中解放出來，以從事更多的創(chuàng)造性工作。同時，CAD技術的應用為后續(xù)的CAM和CAE奠定了基礎，從而為提高壓鑄模設計和加工質量，提高新品開發(fā)速度，降低壓鑄模設計和制造成本，縮短壓鑄件開發(fā)周期創(chuàng)造了極為有利的條件，是未來壓鑄模設計的發(fā)展方向
本次畢業(yè)設計正是利用CAD技術來完成閥蓋壓鑄模的設計。通過本次畢業(yè)設計，不僅可以鞏固所學的理論知識，還可以培養(yǎng)運用所學專業(yè)理論知識的能力，同時提高了應用Pro/E軟件的能力，因而是一次很好的理論和實踐相結合的鍛煉機會。本次畢業(yè)設計源于生產實際，對于我們今后從事實際技術工作有很大的幫助，有利于我們掌握壓鑄模設計的過程和要點，熟悉Pro/E軟件在壓鑄模設計中的應用步驟，為日后的工作打下一個堅實的基礎！
?
二．國外壓鑄現(xiàn)狀及國內壓鑄的發(fā)展特點
2.1國外壓鑄業(yè)現(xiàn)狀
由于科學技術水平的提高和經濟的發(fā)展，以轎車為主體的汽車工業(yè)的蓬勃發(fā)展，加速了壓鑄工業(yè)水平的提升。總體來說，無論是發(fā)展中國家還是發(fā)達國家，壓鑄工業(yè)都是在發(fā)展中。以美國、日本、德國等為代表的工業(yè)發(fā)達國家，雖然工業(yè)發(fā)展處于平衡或有時下降，特別是鑄造業(yè)在上世紀九十年代處于產量降低時期，但由于汽車輕量化日益受到重視，許多鑄鐵件已被鑄鋁件所代替，鎂鑄件的生產及市場也在迅速擴大，使得壓鑄業(yè)的技術上平和生產規(guī)模不斷上升。美國是名符其實的壓鑄件生產大國，美國的壓鑄工業(yè)很發(fā)達，產量和技術都屬全球首位。美國壓鑄業(yè)的發(fā)展對全球有一定的影響，近年來保持略有增長；由于汽車工業(yè)對壓鑄件需求的急劇增長，在本國總體經濟不景氣的背景下，日本壓鑄取得了令人驚異的增長速度，壓鑄年產量不斷創(chuàng)出新高。德國鎂壓鑄件的產量在大幅度的增加。另一方面，企業(yè)之間的兼并和重組的趨勢也在加劇。為緩解競爭壓力，降低成本，發(fā)達國家壓鑄廠家紛紛移師海外發(fā)展。同時，國際上大型汽車廠家的零部件采購進入全球化時代。在這種大環(huán)境中，發(fā)展中國家的壓鑄業(yè)獲得了難得的機遇，近10年來的發(fā)展非常迅速。中國平均年增長率在 10％以上，東南亞地區(qū)和中國臺灣地區(qū)都非?；钴S。（世界各國壓鑄件的產量及市場狀況表1）。統(tǒng)計數(shù)據(jù)表明，大多數(shù)國家的鋁合金壓鑄件占總量的70%左右，鋅合金壓鑄件僅次于鋁合金壓鑄件。每個國家都是汽車制造業(yè)驅動著壓鑄行業(yè)，汽車業(yè)使用的壓鑄件不低于48%（美國），多者可達80%（日本）。
表1 世界各國壓鑄件的產量及市場狀況
國家
壓鑄件產量/t
D或者E
各行業(yè)所占的市場份額比例%
A
B
C
D+E
E
F
G
H
I
J
K
L
中國
208993
1724
72712
1575
1166
64.5
11.4
5.4
9.9
5.7
8.8
日本
711888
2120
40864
930
28
79.9
6.8
6.8
5.7
4
7.6
西班牙
86000
23000
65
15
65
16
3
5
0.8
2
5
德國
271425
3872
65915
215
72
61
2.1
4
3.8
5
0.8
27.5
印度
175000
5200
250
60
5
10
20
墨西哥
50
33
加拿大
82056
10946
21500
60
11
49
5
13
2
美國
611812
20593
173728
430
160
48
11
8
11
澳大利亞
54000
300
6000
90
80
20
?
注：A-鋁合金；B-鎂合金；C-鋅合金；D-壓鑄廠數(shù)量；E-壓鑄車間數(shù)量；F-汽車；G-日用器具；H-機械工業(yè)；I-電機電器；J-電子工業(yè)；K-國防工業(yè)；L-其他 。
2.2國內壓鑄業(yè)的發(fā)展特點
我國壓鑄業(yè)經歷了半個世紀的發(fā)展，特別是近 l0余年來，由于國民經濟的高速發(fā)展，汽車、摩托車工業(yè)的突飛猛進，推動了壓鑄生產的迅速增長 。壓鑄業(yè)的市場前景持續(xù)看好，壓鑄企業(yè)和從業(yè)人員增多，規(guī)模擴大。壓鑄件正在向大型化、復雜化、薄壁化、高性能化、高精度化以及集成化方向發(fā)展，如東風本田、東風日產以及上海皮爾伯格公司都已經實現(xiàn)轎車鋁合金缸體的大批量生產。壓鑄市場的發(fā)展，得益于壓鑄技術的進步。這些先進技術的應用為高質量壓鑄件的大量生產創(chuàng)造了條件?？偟恼f來，我國壓鑄業(yè)技術的發(fā)展具有下列特點：
1）、壓鑄設備能力提升，壓鑄機的自動化程度出現(xiàn)飛躍。由于國內制造水平的整體提高和引進先進的計算機控制技術，我國的壓鑄機制造能力大幅提升，出現(xiàn)了許多具備較強技術實力的大型壓鑄機制造廠商，如深圳領威科技公司、無錫新佳盛公司等。
2）、壓鑄模制造水平大幅提高，壓鑄模制造周期縮短，壓鑄模使用得以延長壽命。除了選用優(yōu)秀的熱作模具鋼外，大型模具廠家紛紛采用數(shù)控加工、電火花、線切割和模具拋光技術來提高模具精度和表面質量，采用真空淬火等熱處理工藝來提高模具的硬度和剛性。
3）、大量壓鑄新工藝得到應用。為降低鑄件廢品率，改善壓鑄件的熱處理性能和焊接性能，真空壓鑄技術、半固態(tài)技術、擠壓鑄造技術被應用到壓鑄生產中。
4）、壓鑄新材料的研究和應用得到推廣。一些改善了合金性能的復合材料，正在從科研院校鑄件應用到企業(yè)生產實踐中。鎂合金壓鑄的應用更是遍地開花，從熔煉、壓鑄、表面處理到回收再利用，形成了完整的產業(yè)鏈，正在產生規(guī)模 效益。
5）、CAD/CAM/CAE技術是提高壓鑄技術水平的重要途徑，能明顯提升企業(yè)的競爭力，因而得到廣泛應用。CAD/CAM技術在國內的應用日益成熟，CAE技術也越來越受到大型企業(yè)的重視。
6）先進的管理理念被導入到企業(yè)的日常管理中，如TS16949質量體系、豐田模式、日產模式等，加強了壓鑄生產過程的控制，有效地降低了企業(yè)的浪費。
?
三．主要研究內容及可行性分析
3.1主要研究內容
根據(jù)圖紙，對罩殼零件進行工藝分析，并確定分型方案、澆注系統(tǒng)位置和大小、抽芯方案、頂出方案等。然后選擇合適的壓鑄機及相關參數(shù)。在此基礎上，進一步確定模具整體結構布置方案。最后采用Pro/E軟件，完成罩殼壓鑄模的模具設計。
3.2可行性分析
該壓鑄件為長方體，模腔較深，頂部無孔，內腔有長凸臺。壁厚較薄而均勻，一般為2mm。材料采用zl102鋁合金。為了做好本次設計本人查閱了大量的參考文獻，從理論上做好充足的準備，進行了模具設計與制造專業(yè)學習，同時學習了材料成型原理等課程，并做過模具設計的課程設計，能熟練使用Pro/E軟件進行建模、裝配、開模和出圖。此外，指導本次設計的老師在工廠從事過技術工作，有大量的實踐經驗，相信在我們的共同努力下，一定能做好本次設計。
四.設計方案
進行工藝分析,完成鑄件CAD建模和鑄件圖，估算出鑄件體積與質量，選擇壓鑄機，設計澆注系統(tǒng)、型腔鑲塊、導向機構模板、推出機構等，并選用材質，最后完成模具設計，輸出全套圖紙
五．預期達到目標
查閱相關文獻，完成開題報告。采用Pro/E軟件，按照壓鑄模設計流程圖完成罩殼壓鑄件全套模具設計，輸出完整的圖紙，并撰寫設計說明書。在這個過程中，鞏固以往所學的理論知識，熟悉壓鑄模結構，掌握壓鑄模的設計方法和Pro/E軟件在壓鑄模設計中的應用步驟，提高動手能力，為將來從事具體的技術工作打下良好的基礎。
圖2 設計流程圖
?
六．關鍵技術難點
本次設計的罩殼零件具有形狀復雜、壁薄、加工面多和氣密性要求高的特點。熔融金屬進入模具型腔中，氣體也隨其一起進入到型腔，它不僅阻礙熔融金屬的流動，而且，合金凝固后留在鑄件中會形成氣孔。特別是對此類薄壁但形狀復雜的零件，型腔對收縮的阻力大，其成型過程復雜，液體金屬在流動過程中極易裹氣好形成紊流。鋁合金材料的熔點溫度高，粘模嚴重，流動時對型腔的沖刷和侵蝕也較嚴重。而澆注系統(tǒng)的位置和大小是解決這些問題的關鍵，因為通過控制內澆口的截面尺寸可以不僅保證合金液的流向，還可以使其具有一定的流量流速和壓力，零件在成型過程中表面能得到很好的冷卻，形成較厚的冷凝層，這也是保證氣密性的重要途徑。因此，本次設計的難點在于深刻理解澆注系統(tǒng)和鑄件成型的關系，冷卻系統(tǒng)和氣孔、粘模的關系，合理設計澆注系統(tǒng)和冷卻系統(tǒng)。
七．工作計劃
?
序號
設計（論文）各階段名稱
日 期
1
制定工作計劃，了解并學習相關知識（壓鑄機、壓鑄模、壓鑄鋁合金、Pro/E軟件等）
1.18-2.25
2
熟悉課題任務要求，收集有關設計資料，查閱相關文獻，掌握相關壓鑄知識和Pro/E軟件，完成開題報告和英文翻譯
2.25-3.19
3
進行工藝分析,完成鑄件CAD建模，輸出鑄件圖，根據(jù)評審結果進行修改
3.20-3.28
4
選擇壓鑄機，布置模具結構，輸出模具裝配草圖，并提交評審
3.29-4.13
5
完成模具設計，輸出全套圖紙
4.14-5.20
6
完善設計、撰寫設計說明書，準備答辯
5.21-6.10
7
畢業(yè)答辯
6.11-6.18
8
畢業(yè)設計資料整改和完善
6.19-6.20
?
參考文獻
[1]駱柟生，許琳.金屬壓鑄工藝與模具設計. 北京:清華大學出版社，2004.
[2]肖乾. Pro／Engineer Wildfire 3.0中文版實用教程. 北京:中國電力出版，2008.
[3]肖乾,周慧蘭. Pro／Engineer Wildfire 3.0中文版模具設計與制造實用教程 . 北京:中國電力出版，2008.
[4]王伯平.互換性與測量基礎第2版. 北京:機械工業(yè)出版社，2007.
[5]鄒玉堂，路慧彪，王躍輝.AUTOCAD2006實用教程.北京:機械工業(yè)出版，2008.
華東交通大學理工學院
本科生畢業(yè)設計
任務書
題 目： 罩殼壓鑄模具設計__________
題目來源：[ ]省部級以上 [ ]校級 [ ]橫向 [ ]自選
題目性質：[ ]理論研究 [ ]應用與理論研究
[ ]應用研究
分 院：機電分院_______________
專 業(yè)：材料成型及控制工程_____
班 級 _______ __________________
學 號：20060410210210 _________
學生姓名：曾智洋__________________
起訖日期：2009年3月9日_________
指導老師：莊文瑋 職稱：副教授
審核日期：__________________________
說 明
1、畢業(yè)設計任務書由指導老師填寫，并經分院審定，下達到學。
2、學生根據(jù)指導老師下達的任務書獨立完成開題報告，于3周內提交給知道老師批閱。
3、本任務書在畢業(yè)設計完成后，與論文一起交給指導老師，作為論文批閱和畢業(yè)設計答辯的主要檔案資料，是學士學位論文成冊的主要內容之一。
一、畢業(yè)設計的要求和內容（包括原始數(shù)據(jù)、技術要求、工作要求）
確定分型面（有兩個以上方案比較），確定澆注系統(tǒng)和排溢系統(tǒng)（有計算或查表），計算型芯、型腔高度和徑向尺寸，確定推出機構（和側向分型與抽芯機構），選擇標準模架，并校核模板側壁和底面厚度，確定加熱于冷卻系統(tǒng)。
確定和校核型腔數(shù)目，校核注射量，校核塑件在分型面上的投影面積和鎖模力，校核注射壓力，校核開模行程，校核模具與注射機安裝部分尺寸，校核頂出裝置，選擇注塑機。
二、畢業(yè)設計圖紙內容及張數(shù)
1、模具裝配圖一張，附零件圖。
2、模具零件圖若干張（五張以上）。
三、畢業(yè)設計實物內容及要求
設計圖樣全部用計算機繪制（二維和三維的，先手繪裝配圖草圖），符合最新制圖標準；投影正確，表達完整，布局合理。
注重模具結構和裝配要求，功能滿足，實用可靠。
理論分析完整清楚；設計推導簡明扼要；計算正確可靠。避免冗長，反對抄襲。
四、畢業(yè)設計進度計劃
序號
各階段工作內容
起訖日期
備注
1
壓鑄件工藝分析
2010-3-9
開始分析壓鑄件
2
計算壓鑄件的體積
2010-3-18
計算壓鑄件體積
3
確定壓鑄工藝參數(shù)
2010-3-25
計算相關工藝參數(shù)
4
選擇壓鑄機校核
2010-4-8
壓鑄機選擇
5
模具結構設計
2010-4-17
設計模具結構
6
型芯及型腔計算
2010-4-27
計算型芯及型腔
7
畫圖
2010-5-10
畫出相關零件圖裝配圖
8
編寫設計說明書
2010-5-18
完成說明書
五、主要參考資料
[1]駱柟生，許琳.金屬壓鑄工藝與模具設計. 北京:清華大學出版社，2004.
[2]肖乾. Pro／Engineer Wildfire 3.0中文版實用教程. 北京:中國電力出版，2008.
[3]肖乾,周慧蘭. Pro／Engineer Wildfire 3.0中文版模具設計與制造實用教程 . 北京:中國電力出版，2008.
[4]王伯平.互換性與測量基礎第2版. 北京:機械工業(yè)出版社，2007.
[5]鄒玉堂，路慧彪，王躍輝.AUTOCAD2006實用教程.北京:機械工業(yè)出版，2008.
執(zhí)行任務
書時間
2010.3.8
完成畢業(yè)
設計時間
2010.5.23
外文資料翻譯
系 別 XXXXXXX
專 業(yè) XXXXX
班 級 XXXX
姓 名 XXX
學 號 XXXXX
指導教師 XXXXXX
2010年4月
Compression casting craft and compression casting mold design main point
Abstract: The die-casting machine, the mold and the alloy three, take press the casting as this, among the compression casting craft penetration, their conformity is organically a effective system, causes the die-casting machine and the mold obtains the good match, plays the optimization to press the casting structure, the optimal die-casting machine, the optimization presses the mold design, enhances the craft operating point the flexible role, thus provides the reliable guarantee for the compression casting production.Therefore, the compression casting craft lies within in the mold saying, depth of the connotation is self-evident.
Key word: Die-casting machine; Mold; Compression casting craft; The mold designs
1.Die-casting machine - mold - alloy system
Die-casting machine, the mold and alloy these three factors, in presses in the casting production process, they constituted a system, namely the die-casting machine - mold - alloy system, it is take presses the casting as this, among the craft penetration, entrusts with the system vigor and the efficiency, but the mold is the craft enters the system the platform.The die-casting machine, the mold and the alloy three relations expressed vividly as shown in Figure 1.
The die-casting machine - mold - alloy system main performance is:
(1)Ingate position influence backfill metal melt flow direction and the condition, with the backfill die space quality, have the decisive influence to the mold structure and the craft, this is the key is at.
(2)Designation best sufficient time, this is extremely important one step, affects to sufficient time metal melt rate of volume flow (Q), also is the sufficient power, according to the above and computation ingate size.
(3)Choice exhaust, overflow position and size, except outside normal exhaust, pollution discharge and temperature balance, but also may reduce the impact pressure, avoids the metal splashing and producing the burr.
(4) Heating and cooling, balanced mold temperature, maintenance operating temperature.
2.Compression casting crafts and the mold design key technologies
When compression casting the ingate position influence presses the casting the structural design, the quality and the compression casting mold design, may obtain the correct establishment ingate position prompt through the inquiry material.As a result of the casting structure multiplicity, must choose the ingate the correct position is very difficult, but also has some basic requests, like thought generally the establishment ingate must cause sufficient when the metallic jet has as far as possible compared the long distance by the open jet in the die space average, also is the correct ingate position, the shape, the size (flows to angle) to coordinate the compression casting parameter to be possible to obtain the metallic jet to expand along the wall unceasing order, to change, and continuously expands to the terminus.The die space majority (i.e. branch die space) completes by the jet flow backfill, only then a small part of die space (i.e. non-branch die space) by the metal melt branch supplemented completes or collides by the metal melt stock class completes the backfill, and overflows the system elimination vestiges through the platoon.Figure 2 is in the pouring position and branch die space schematic drawing [1]”.
The identical pressure casting choice different ingate position and flows to the angle, when may obtain the area percentage which the different branch die space, the non-branch die space and hold respectively, Figure 2 the shell compression casting, because the ingate position is different, obtains the different branch die space and the non-branch die space.The chart 2a ingate is vertical to one side wall, because the components crown long square edged orifice separates two sidewalls, the result is only then one side for the branch die space; Must fill another one side wall, must pass through the running channel both sides attachment point, the final two liquid flow gathering completes the packing, this part is the non-branch die space.Because the branch die space accounts for the area percentage not to be high, therefore can produce the massive waste products, like chart 2a1.In chart 2b, the ingate position does not make the change, only is wall thickness and so on crown rectangle Kong Yong craft muscles connects, like this fills when the metal melt changes, fills another one side wall along the muscle board, caused two sidewalls both to become the branch die space, increased the branch die space to account for the percentage, the casting quality also large scale enhances, like chart 2b1.In chart 2c, the components and chart 2a are same, the crown square edged orifice does not add the craft muscle, but establishes the ingate in a components end, such metal melt simultaneously carries on the backfill from two sidewalls, thus expanded the branch die space percentage, had guaranteed the quality, enhanced the qualified rate.This is the identical components three kind of ingate establishment plan, the proof ingate position crucial nature.
Although the computer technology is helpful to the designation ingate position, but the computer technology is only one method, but the ingate position design did not lose was still a key technologies.
Between 3 compression casting craftmain point
3.1 metal pressures, the speed and the current capacity relations
In the principle the die-casting machine are a liquid metal pump, it transports under the pressure the metal melt to the compression casting model cavity in.The pump characteristic is transports the power (rate of volume flow), is the pressure function, this aspect as early as in the 70's, first makes the valuable development work by Australian Asia CSIRO, has established a useful tool with the pQ2 chart, according to the casting i.e. mold request, decided the machine the adjustment value, is originally uses in the hot cell die-casting machine the zinc base alloy pressing in the casting, but very quick expands to Leng Shiji on.In principle, now the pressure and the rate of volume flow relations which knew very well from the hydromechanics principle, shifts to the die-casting machine practical application.
The metal pressure is higher, is also quicker in the spray nozzle and the ingate place metal melt flow rate, but also must consider victory flow resistance which as a result of the flowing section change, the direction change and the wall roughness existence produces, xi expresses sum of the these resistance with the friction coefficient.
If the known immeasurable steel coefficient xi, may calculate the metal pressure which certain ingate speed needs, according to the compression casting alloy and the casting request, the ingate speed has an empirical value, should observe, see Table 1, therefore needs the die-casting machine to provide the corresponding speed.
Table 1 ingate speed selection
Table 1 Choice of velocity at ingate
Project
A1
Mg
Cu
Zn
υa(m.s-1)
25-60
40-90
30-45
30-50
The low value uses in the relatively thick casting, the high value uses in the relatively thin casting, common magnesium alloy casting ingate speed compared to aluminum high25%. Time the vacuum die casting ingate speed is 15-30m/s.
3.2 Take the casting as this, optimizes the die-casting machine - mold - alloy system, enhances the craft flexibility
In the die-casting machine - mold - alloy system, through the adjustment craft parameter, may improve presses the casting the quality and the performance.These craft parameter defined with work window (OW).This indicated OW is these craft parameter limit chart.In the compression casting craft, the sufficient time, the ingate speed and the final metal static pressure use to define OW, these parameters and sufficient phenomenon related, relies on in the mold design and the die-casting machine performance.Designs when the mold, in OW all spots were considered all is equal, and does not have the priority, may think the best operating point exists in OW unknown lights, in presses the mold installs on the die-casting machine in front of the experimental mold is unable to find it.In the mold design stage guaranteed easy to find the good operating point is based on the flexible consideration, the flexibility is obtains in OW through the adjustment.
Therefore, divides into the craft parameter the soft parameter and the hard parameter two kinds, the soft parameter is refers through the operation or a control device carries on the adjustment the parameter, like parameters and so on power level, metal pressure, melt temperature, mold temperature and cycle time.The die-casting machine which the hard parameter is refers to which one kind to have to revise the mold or simultaneously must revise, like drift diameter, ingate area, air discharge duct and so on.Soft parameter when experimental mold easy to change and to obtain successfully, the hard parameter changes then both the difficulty and costs a great deal of money, time-consuming, needs to disassemble the mold frequently in order to revise.Therefore, the optimized method is and expands the OW internal assignment integral point based on the soft parameter the flexibility, thus provides the great scope for the mold experiment, avoids the time-consuming expensive mold change.
3.3 shoots the curve from the pressure to mention
Now die-casting machine Chang Peiyi three level of compression casting systems: The level advances gradually for the drift idling speed, pushes the metal melt to the ingate, namely the so-called slow pressure shoots the stage; The second level is the drift by high speed the metal melt through the ingate, fills the die space in the stipulation time, namely sufficient stage; The third level for the casting which not yet completely coagulates under the high pressure (starts pressure intensifier) to carry on the coagulation and by the compaction, namely compaction stage.Shown in Figure 17 for the model three levels of pressures shoots the curve schematic drawing, attempts the curvature to divide into the level slow pressure to shoot, two levels sufficient and three level of turbo-charged compaction three stages.Some pressures shoot the system to shoot the level pressure divide into two small parts, the first part is the drift seals up the pouring material mouth (shown in Figure 18 the X1 line) first, the second part shoots the stage for the slow pressure, then carries on the light again and the compaction, this became four levels of pressures to shoot the system, like this except might avoid the melt splashing the pouring material mouth, might raise the compression chamber initial fullness.
3.3.1. Slow pressures shoot the stage
Slow pressure to shoot the stage mainly are elect in the craft to control the slow pressure to shoot the speed, the goal are wells up when the metal melt to the ingate, presses in the room the gas to be able completely from the runner to enter the die space, but by the metal melt package, does not avoid in the casting forming the blowhole; Therefore, needs to choose a critical drift speed, may be the constant acceleration, also may be the constant speed, said generally, the constant acceleration effect is good.The overseas die-casting machine matches by “Parashot'' or “SIMUI” the constant acceleration slow pressure shoots the speed elects to control the system, Figure 19, chart 20[2] may take elects to control the slow pressure to shoot reference the speed.
3.3.2. Sufficient stages
This stage most should pay attention in the craft: The sufficient time, the pressure shoot the speed, the ingate speed and the air pressure shoot the speed the reciprocity, and mainly wants the parameter the choice.
3.3.2.1.Best sufficient time
The sufficient time is the metal melt has flowed the ingate, by the high ingate speed, fills the die space before the metal melt stop flowing the time.This time is very short, is an extremely essential parameter, selects the die-casting machine, carries on foundation which the technological design and the mold design.
The sufficient time must be short, the goal is sufficient when does not have the early time in the casting smallest spot or the liquid flow far-end to coagulate, avoids the casting appearing lacks flaws and so on meat, cold shot.The sufficient time is shorter, the sufficient speed is higher, can enlarge the die space to wear, but but also possible to splash because of zhang the metal and to produce the edge; The sufficient speed is high, can enable in the die space the gas not to have the enough time to transgress from the die space.The sufficient time correct choice only then the overall evaluation can obtain, Table 3 gave has chosen the sufficient time and ingate speed correlation factor [4].
The metal melt had decided from the operating temperature to the temperature of solidification release quantity of heat it maintains the castability under the same thermal conductivity time, therefore this kind of thermal then achievement determines its may imitate the time criterion most greatly.The release quantity of heat and the sufficient time are proportional, compared to may obtain several kind of alloy sufficient time relations according to the quantity of heat.The Mg alloy, the Zn alloy, the A1 alloy and the Cu alloy under the same coagulation condition, from the operating temperature to the temperature of solidification release quantity of heat respectively are 261, 329, 509, 918kCal/dm3, then they the time ratio is τMg: τZn: τAI: τCu ≈0.51: 0.65:1:1.8.In other words, τMg=: 0.51τAI, τZn=0.65τAI, τCu=1.8τAI.
When compression casting obvious molten metal in die space not superheat, the people observe the melt to flow have certain quantity solid phase, when the solid phase rate achieved30%-80%, In the die space the bath movement only can through the high rate of inflow, when best sufficient time according to type (17) computation, quite Yu Fzhi is70%-80%.
The best sufficient time speaking of each kind of magnesium alloy shoots when the pressure must the aluminum alloy be quicker than at least 2 times, the copper alloy best sufficient time and the alloy composition element related, the leaded brass (CuZn37Pb) and the magnesium alloy is close, the silicon brass (CuZnl5Si4) and the aluminum alloy is close.
The casting surface quality quantity increases along with the sufficient time changes, the sufficient time is short, the pressure shoots the power to be big, sufficient is quick, but because of the ingate thickness limit, the excessively short sufficient time causes the casting the factor of porosity increase.Figure 22 is the sufficient time presses the casting quality to the aluminum influence [7].Chart 23[3,8] is one kind which the recent years proposed to the aluminum, the magnesium presses the casting wall thickness and the sufficient time relations relational graph.The superficial quality requests to choose the short sufficient time high.
3.3.2.2 Pressure shoots the speed, the sufficient speed and the air pressure shoots the speed.
(1) Pressure shoots the speed (drift speed)
The pressure to shoot the speed (drift speed) is in the sufficient stage unit time drift displacement.In traveling schedule curve sufficient stage no matter what chooses two spots, the survey traveling schedule distance and the sufficient time, then obtain the pressure to shoot the speed = survey the distance (mm)/pressure to shoot time (ms).
(2)Sufficient speed (ingate speed)
The sufficient speed is the ingate speed, concerns with the drift speed and the drift area.In presses in the room - - mold this loop system, take the sufficient time metal passes the ingate rate of volume flow Q as the foundation.Only then after designated generally the die-casting machine, can determine the drift area, the ingate speed may according to Table 1 selection.
The ingate speed is the important parameter, has the important influence to the casting quality and the mold life.The ingate speed excessively is high can increase the die space surface because corrodes, sticks the probability which the mold receives damages; Although the low ingate speed is advantageous in the gas discharges from in vivo, but also can cause the casting mechanics performance and the surface quality goes bad.The casting volume flaw often appears by the uniform distribution micro hole or by the big hole in the casting, high ingate speed compression casting strength ratio low ingate speed low, is helpful in forms the micro hole in the casting, causes the casting surface to be brighter and cleaner, the organization is more compact.
Ingate speed and casting wall thickness related, but decided by the ingate thickness, the actual same wall thickness casting, possibly has the different thickness ingate, from this also can use the different ingate speed to come the compression casting.
But has to ingate structure experience graph [2], confirmed the ingate structure and the ingate speed, when to casting quality influence, recommendation fine casting operating point region thin-walled casting, in choice neighbor chart grid area.Obviously, when very thin ingate, because the ingate parameter is the low value, the need higher ingate speed.
Sufficient time drift speed υo excessively high, besides to mold life and casting quality influential, but also can because the sufficient end time drift impact function, has caused to move, to decide the mold to push, when is pushed the slit to surpass 0.05-0.15 mm, but also can produce the molten metal the phenomenon which splashes from the mold comes out.
Sufficient time ingate speed υa with casting wall thickness and metal melt in die space flow length related, as shown in Figure 27.
(3) Biggest air pressure shoots the speed
Biggest air pressure to shoot speed υot max is presses in the room not to have in the situation which the metal also the governor valve all start, in unit time drift displacement.It is the cold room die-casting machine important technical parameter, to has the metal sufficient time drift speed υ0, in the running channel speed υa and presses the casting quality to have the important influence.
(a) Compression casting machine-pressed shoots the power which the system can provide
For in the short sufficient time introverted die space to fill the large capacity metal melt, needs the high drift speed and in the running channel speed, this must entrust with the die-casting machine high biggest air pressure to shoot the speed.The modern Europe die-casting machine biggest air pressure shoots the speed to achieve 11m/s, Japan recent years also appeared 10m/s the supervelocity die-casting machine.
(b) Air pressure shoots the speed
Air pressure to shoot the speed is the die-casting machine adjustable parameter.Because presses the room - die space system resistance the existence, the sufficient time drift speed always shoots the speed the air pressure to be much smaller than.May know by chart 30[4], when certain in running channel area υot max increases from 4m/s to 8m/s, but the sufficient time drift speed υo enhances from 2.4m/s (I) to 3.1 m/s(II), does not look like υot max such to enhance 1 time.
Theoretically, when the pressure shoots the output is biggest υ02/υ ot max2=Q2/Q at max2=1/3, then υ0/υot max2=Q/Qot max=0.577, as shown in Figure 31.Thenυ0=0.577 upsilon ot max.
The cold-press room die-casting machine must have the high level most greatly spatial
Pressure to shoot the speed, like this may improve the craft operating point spiriactiveness.The graphic solution may help us to choose the die-casting