吊耳加強(qiáng)板零件的沖壓工藝與沖模設(shè)計(jì)
吊耳加強(qiáng)板零件的沖壓工藝與沖模設(shè)計(jì),加強(qiáng),零件,沖壓,工藝,沖模,設(shè)計(jì)
畢業(yè)設(shè)計(jì)(外文翻譯)
題目:吊耳加強(qiáng)板零件的沖壓工藝與沖模設(shè)計(jì)
專 業(yè) 名 稱 機(jī)械設(shè)計(jì)制造及自動(dòng)化
班 級(jí) 學(xué) 號(hào) 078105318
學(xué) 生 姓 名 羅賢明
指 導(dǎo) 教 師 陳為國(guó)
填 表 日 期 2011 年 3 月 1 日
吊耳加強(qiáng)板的沖壓工藝與沖模設(shè)計(jì)
學(xué)生姓名:羅賢明 班級(jí):0781053
指導(dǎo)老師:陳為國(guó)
摘要:近年來(lái),我國(guó)家電工業(yè)的高速發(fā)展對(duì)模具工業(yè),尤其是冷沖模具提出了越來(lái)越高的要求,2004年,冷沖模具在整個(gè)模具行業(yè)中所占比例已大大上升,據(jù)有關(guān)專家預(yù)測(cè),在未來(lái)幾年中,中國(guó)冷沖模具工業(yè)還將持續(xù)保持年均增長(zhǎng)速度達(dá)到15%左右的較高速度的發(fā)展。
沖壓成型是金屬成型的一種重要方法,它主要適用于材質(zhì)較軟的金屬成型,可以一次成型形狀復(fù)雜的精密制件。本課題就是將石化、化工、電力等行業(yè)的法蘭密封結(jié)構(gòu)中的墊片作為設(shè)計(jì)模型,將冷沖模具的相關(guān)知識(shí)作為依據(jù),闡述冷沖模具的設(shè)計(jì)過(guò)程。
本設(shè)計(jì)對(duì)帶法蘭U型件進(jìn)行的模具設(shè)計(jì),利用Auto CAD軟件對(duì)制件進(jìn)行設(shè)計(jì)繪圖。明確了設(shè)計(jì)思路,確定了沖壓成型工藝過(guò)程并對(duì)各個(gè)具體部分進(jìn)行了詳細(xì)的計(jì)算和校核。如此設(shè)計(jì)出的結(jié)構(gòu)可確保模具工作運(yùn)用可靠,保證了與其他部件的配合。并繪制了模具的裝配圖和零件圖。
本課題通過(guò)對(duì)工件的沖壓模具設(shè)計(jì),鞏固和深化了所學(xué)知識(shí),取得了比較滿意的效果,達(dá)到了預(yù)期的設(shè)計(jì)意圖。
關(guān)鍵詞:沖壓模具;沖壓成型;模具設(shè)計(jì)
指導(dǎo)老師簽名:
Lug Reinforcement stamping process and die design
Studentname:luoxianming Class:0781053
Supervisor:chenweiguo
Abstract:In recent years, the rapid development of China's household electrical appliance industry of mold industry, especially Die with the increasing demands put forward in 2004, Die in the proportion of the entire mold industry has been greatly increased, experts predict, In the next few years, China will continue to maintain industrial Die average annual growth rate reached 15% of the high rate of development.
Stamping is an important method of metal forming, it is mainly applied to relatively soft metal forming, can be a molding of precision parts of complex shape. This topic is to petrochemical, chemical, electric power industries in the flange gasket sealing structure as a design model, Die related knowledge as a basis to explain the design process of Die.
The design of the U-piece with a flange to the mold design, the use of Auto CAD software to design parts drawing. Clear design ideas, determine the process of stamping and forming part of the various specific details of the calculation and verification. The structure of such a design die is used to ensure reliability, ensure coordination with other components. And the mapping of the mold assembly and part drawings.
The subject of the workpiece by stamping die design, consolidate and deepen the knowledge, and achieved satisfactory results, to achieve the desired design intent.
Keywords: stamping die; stamping molding; die design
Signature of supervisor:
畢業(yè)設(shè)計(jì)(論文)
題目:吊耳加強(qiáng)板零件的沖壓工藝與沖模設(shè)計(jì)
專 業(yè) 名 稱 機(jī)械設(shè)計(jì)制造及自動(dòng)化
班 級(jí) 學(xué) 號(hào) 078105318
學(xué) 生 姓 名 羅賢明
指 導(dǎo) 教 師 陳為國(guó)
填 表 日 期 2011 年 6 月 1 日
畢業(yè)設(shè)計(jì)(論文)開(kāi)題報(bào)告
題目吊耳加強(qiáng)板的沖壓與沖模設(shè)計(jì)
專 業(yè) 名 稱 機(jī)械設(shè)計(jì)制造及其自動(dòng)化
班 級(jí) 學(xué) 號(hào) 078105318
學(xué) 生 姓 名 羅賢明
指 導(dǎo) 教 師 陳為國(guó)
填 表 日 期 2011 年 3 月 1 日
說(shuō) 明
開(kāi)題報(bào)告應(yīng)結(jié)合自己課題而作,一般包括:課題依據(jù)及課題的意義、國(guó)內(nèi)外研究概況及發(fā)展趨勢(shì)(含文獻(xiàn)綜述)、研究?jī)?nèi)容及實(shí)驗(yàn)方案、目標(biāo)、主要特色及工作進(jìn)度、參考文獻(xiàn)等內(nèi)容。以下填寫(xiě)內(nèi)容各專業(yè)可根據(jù)具體情況適當(dāng)修改。但每個(gè)專業(yè)填寫(xiě)內(nèi)容應(yīng)保持一致。
一、選題的依據(jù)及意義:
1..1本課題研究的主要內(nèi)容
(1)對(duì)給定零件進(jìn)行工藝分析并確定工藝方案
(2)吊耳加強(qiáng)板總體結(jié)構(gòu)設(shè)計(jì)及相關(guān)工藝計(jì)算
(3)進(jìn)行吊耳加強(qiáng)板的沖模設(shè)計(jì)
(4)繪制吊耳加強(qiáng)板的零件圖
(5)擬定主要零件的加工工藝
(6)編寫(xiě)設(shè)計(jì)說(shuō)明書(shū)
1.2課題研究的意義
本課題要求對(duì)給定的零件托架進(jìn)行沖壓工藝,通過(guò)對(duì)零件進(jìn)行詳細(xì)的工藝分析確定零件的沖壓工藝方案并制定部分零件的制造工藝。通過(guò)課題讓我們能夠掌握中等復(fù)雜程度零件的沖壓工藝與沖模設(shè)計(jì)和制造的一般方法,對(duì)零件沖壓工藝方案的確定、工藝計(jì)算及沖模設(shè)計(jì)有更深層次的認(rèn)識(shí),并學(xué)會(huì)對(duì)沖模設(shè)計(jì)資料的檢索與整合以及對(duì)已有資料的充分合理的使用,該實(shí)踐性課題是對(duì)學(xué)生理論學(xué)習(xí)水平的實(shí)踐和檢驗(yàn),可對(duì)以后從事類似的工作有一定的指導(dǎo)性和實(shí)踐性意義。
二、國(guó)內(nèi)外研究概況及發(fā)展趨勢(shì)(含文獻(xiàn)綜述):
2.1沖壓技術(shù)的發(fā)展現(xiàn)狀
隨著科學(xué)技術(shù)的不斷進(jìn)步,工業(yè)產(chǎn)品日益復(fù)雜與多樣化,產(chǎn)品性能和質(zhì)量也在不斷提高,因而對(duì)沖壓技術(shù)提出了更高的要求。沖壓技術(shù)自身也在不斷地創(chuàng)新和發(fā)展。為了適應(yīng)大批量、高效率生產(chǎn)的需要,在沖壓模具和設(shè)備上廣泛應(yīng)用了各種自動(dòng)化的進(jìn)出料機(jī)構(gòu)。對(duì)于大中型沖壓件,例如汽車覆蓋件,專門配置了機(jī)械手或機(jī)器人。這不僅僅大大提高了沖壓件的生產(chǎn)品質(zhì)和生產(chǎn)率,而且也增加了沖壓工作的安全性。在中小件的大批量生產(chǎn)方面,現(xiàn)已廣泛應(yīng)用多工位級(jí)進(jìn)模,多工位壓力機(jī)或高速壓力機(jī)。在中小批量多品種方面,正在發(fā)展柔性制造系統(tǒng)。
2.2CAD/CACAM等技術(shù)的不斷深入應(yīng)用,使模具質(zhì)量提高、生產(chǎn)周期下降。
先進(jìn)沖壓技術(shù)是指導(dǎo)信息技術(shù)/新材料/新工藝與傳統(tǒng)沖壓成形技術(shù)的結(jié)合。目前,沖壓行業(yè)的技術(shù)水平和先進(jìn)性,要表現(xiàn)在以CAD/CAE/CAM技術(shù)為代表的數(shù)字化與信息化程度,及企業(yè)中信息集成和管理網(wǎng)絡(luò)程度。目前,國(guó)內(nèi)汽車覆蓋件模具生產(chǎn)企業(yè)已經(jīng)普遍采用了CAD/CAE/CAM技術(shù),CAPP技術(shù)也已經(jīng)開(kāi)始使用。
隨著計(jì)算機(jī)的深入使用,我國(guó)不少企業(yè)已經(jīng)在嘗試或開(kāi)展計(jì)算機(jī)輔助沖壓工藝設(shè)計(jì)CAPP系統(tǒng)已從工藝設(shè)計(jì)發(fā)展到工藝信息的管理,設(shè)計(jì)方法也從派生式、混合式、創(chuàng)成式三種CAPP系統(tǒng)并舉的局面向智能化的混合式方向發(fā)展。但很多地方仍需要設(shè)計(jì)人員的決策與經(jīng)驗(yàn),真正實(shí)用的基于知識(shí)的大型復(fù)雜沖壓件CAPP系統(tǒng)尚未建立。由于沖壓工藝設(shè)計(jì)過(guò)程的復(fù)雜性和模糊性,想要全面有效的決問(wèn)題,需要一種新型智能型工程設(shè)計(jì)方法,即基于知識(shí)工程的KBE技術(shù)及信息管理技術(shù)綜合應(yīng)用到?jīng)_壓件工藝設(shè)計(jì)中,建立智能優(yōu)化的CAPP系統(tǒng),并實(shí)現(xiàn)與CAD/CAE/CAM及管理的集成化,將是該領(lǐng)域未來(lái)的發(fā)展方向。
總的來(lái)說(shuō),中國(guó)目前的機(jī)械制造還需要進(jìn)一步調(diào)整,增長(zhǎng)方式也需要進(jìn)一步轉(zhuǎn)變,必須從大量的擴(kuò)張逐漸轉(zhuǎn)變到以質(zhì)為先的軌道上來(lái)。只有這樣,我國(guó)機(jī)械制造產(chǎn)品的質(zhì)量與水平才能真正提升,才能擁有國(guó)際市場(chǎng)的競(jìng)爭(zhēng)力,才能使機(jī)械制造產(chǎn)品的出口量的增長(zhǎng)與質(zhì)的提升相結(jié)合。21世紀(jì)的今天,中國(guó)憑借豐富且廉價(jià)的人力資源、龐大的市場(chǎng)及其他許多有利條件,已成為承接工業(yè)發(fā)達(dá)國(guó)家機(jī)械制造業(yè)轉(zhuǎn)移的良好目的地。隨著國(guó)際交往的日益增多和外資在中國(guó)機(jī)械制造行業(yè)的投入日益增多,中國(guó)機(jī)械制造已經(jīng)于世界機(jī)械制造密不可分,中國(guó)機(jī)械制造在世界機(jī)械制造中的地位和影響也會(huì)越來(lái)越重要
三、研究?jī)?nèi)容及實(shí)驗(yàn)方案:
下圖所示為某車型上的吊耳加強(qiáng)板零件,材料為35鋼,料厚2mm。該零件為一淺的無(wú)凸緣拉伸件。
其拉伸高度僅5mm,基本與R2mm圓弧重合,其拉伸高度無(wú)特別要求。零件中間有一個(gè) Ф48
+0.8
+0.4mm的圓孔,其精度要求不算高,直接沖壓即能夠滿足要求。該零件的生產(chǎn)綱領(lǐng)不多,應(yīng)用戶的要
求,決定用通用的曲柄壓力機(jī)加工,其沖壓工藝為:落料、沖孔→拉伸成形。
36.51)方案對(duì)比
方案一:先沖孔,再?gòu)澢?,后落料。單工序模生產(chǎn)。
方案二:沖孔—彎曲—落料級(jí)進(jìn)沖壓。級(jí)進(jìn)模生產(chǎn)。
方案三:落料-拉深-沖孔復(fù)合模沖壓。復(fù)合模生產(chǎn)。
表2-1 各類模具結(jié)構(gòu)及特點(diǎn)比較
模具種類比較項(xiàng)目
單工序模
(無(wú)導(dǎo)向)(有導(dǎo)向)
級(jí)進(jìn)模
復(fù)合模
零件公差等級(jí)
低
一般
可達(dá)IT13~I(xiàn)T10級(jí)
可達(dá)IT10~I(xiàn)T8級(jí)
零件特點(diǎn)
尺寸不受限制厚度不受限制
中小型尺寸厚度較厚
小零件厚度0.2~6mm可加工復(fù)雜零件,如寬度極小的異形件
形狀與尺寸受模具結(jié)構(gòu)與強(qiáng)度限制,尺寸可以較大,厚度可達(dá)3mm
零件平面度
低
一般
中小型件不平直,高質(zhì)量制件需較平
由于壓料沖件的同時(shí)得到了較平,制件平直度好且具有良好的剪切斷面
生產(chǎn)效率
低
較低
工序間自動(dòng)送料,可以自動(dòng)排除制件,生產(chǎn)效率高
沖件被頂?shù)侥>吖ぷ鞅砻嫔?,必須手?dòng)或機(jī)械排除,生產(chǎn)效率較低
安全性
不安全,需采取安全措施
比較安全
不安全,需采取安全措施
模具制造工作量和成本
低
比無(wú)導(dǎo)向的稍高
沖裁簡(jiǎn)單的零件時(shí),比復(fù)合模低
沖裁較復(fù)雜零件時(shí),比級(jí)進(jìn)模低
適用場(chǎng)合
料厚精度要求低的小批量沖件的生產(chǎn)
大批量小型沖壓件的生產(chǎn)
形狀復(fù)雜,精度要求較高,平直度要求高的中小型制件的大批量生產(chǎn)
根據(jù)分析結(jié)合表分析:
方案一模具結(jié)構(gòu)簡(jiǎn)單,制造周期短,制造簡(jiǎn)單,但需要兩副模具,成本高而生產(chǎn)效率低,難以滿足大批量生產(chǎn)的要求。
方案二只需一副模具,生產(chǎn)效率高,操作方便,精度也能滿足要求,模具制造工作量和成本比較高。適合大批量生產(chǎn)。
方案三只需一副模具,制件精度和生產(chǎn)效率都較高,且工件最小壁厚大于凸凹模許用最小壁厚模具強(qiáng)度也能滿足要求。沖裁件的內(nèi)孔與邊緣的相對(duì)位置精度較高,板料的定位精度比方案三低,模具輪廓尺寸較小。
通過(guò)對(duì)上述三種方案的分析比較,該工件的沖壓生產(chǎn)采用方案一為佳。由于本設(shè)計(jì)只討論拉深工藝和拉深模具的設(shè)計(jì),所以使用一套單工序的拉深模具進(jìn)行生產(chǎn)即可。
四、目標(biāo)、主要特色及工作進(jìn)度
(1) 通過(guò)對(duì)托架工件的工藝分析,確定工作的重點(diǎn)主要集中在模具工作部分零件的設(shè)計(jì)(例凸模,凹模,凸凹模),各種固定板的設(shè)計(jì)和相關(guān)尺寸的計(jì)算和校核。
(2) 設(shè)計(jì)前后工序的關(guān)聯(lián)性以及模具的關(guān)聯(lián)性,合理安排工序,盡量使模具的結(jié)構(gòu)更緊密,同時(shí)在模具的設(shè)計(jì)過(guò)程中還要考慮到所設(shè)計(jì)的零件的課加工性,要盡量多的選用標(biāo)準(zhǔn)件,達(dá)到規(guī)范化設(shè)計(jì)的要求成為此畢業(yè)設(shè)計(jì)的難點(diǎn)。
(3) 針對(duì)此次模具設(shè)計(jì)工作量大,工作難度大的特點(diǎn),擬采用計(jì)算機(jī)輔助設(shè)計(jì)AutoCAD、UG等相關(guān)軟件來(lái)完成模具的設(shè)計(jì),從而節(jié)省時(shí)間和精力;收集相關(guān)文獻(xiàn)、期刊論文來(lái)加以輔助設(shè)計(jì);針對(duì)自身理論方面的不足將更多的向輔導(dǎo)老師請(qǐng)教學(xué)習(xí);當(dāng)然,具體的設(shè)計(jì)中也要不斷的去實(shí)踐設(shè)計(jì)的模具的實(shí)用性與經(jīng)濟(jì)性,使設(shè)計(jì)更趨于精確化,規(guī)范化,系統(tǒng)化。
設(shè)計(jì)中所提供的托架材料為厚度2mm的35鋼,該零件沖孔落料彎曲成形。一般沖制該零件需落料、沖孔、彎曲等基本工序來(lái)完成。為了減少工序,對(duì)該零件進(jìn)行詳細(xì)分析研究,并查閱有關(guān)資料,認(rèn)為該零件可有兩幅模具完成,一副沖孔落料復(fù)合模,一副彎曲模。
工作進(jìn)度:
1.收集有關(guān)資料,撰寫(xiě)開(kāi)題報(bào)告; 1周
2.英文翻譯(6000實(shí)詞以上) 1周
3.繪制吊耳加強(qiáng)板沖件圖,應(yīng)用Fastform軟件進(jìn)行CAE分析 4周
4.編制吊耳加強(qiáng)板沖壓成形工藝規(guī)程; 2周
5.繪制吊耳加強(qiáng)板成形??傃b圖及零件圖; 6周
6.撰寫(xiě)畢業(yè)設(shè)計(jì)說(shuō)明書(shū)(論文) 3周
7.畢業(yè)設(shè)計(jì)審查,畢業(yè)答辯。 1周
五、參考文獻(xiàn)
1.《沖模設(shè)計(jì)手冊(cè)》編寫(xiě)組.沖模設(shè)計(jì)手冊(cè).北京:沖模設(shè)計(jì)手冊(cè),1995
2.陳為國(guó).吊耳加強(qiáng)板沖壓工藝及沖模設(shè)計(jì).模具制造,2002.6
3.王新華,袁聯(lián)富編.沖模結(jié)構(gòu)圖冊(cè).北京:機(jī)械工業(yè)出版社,2003
4.羅益旋.沖壓新工藝新技術(shù)及模具設(shè)計(jì)實(shí)用手冊(cè). 銀聲音像出版社,2004
5. GB2851~2875《冷沖?!穱?guó)家標(biāo)準(zhǔn)
畢業(yè)設(shè)計(jì)(論文)任務(wù)書(shū)
I、畢業(yè)設(shè)計(jì)(論文)題目:
吊耳加強(qiáng)板零件沖壓工藝與沖模設(shè)計(jì)
II、畢 業(yè)設(shè)計(jì)(論文)使用的原始資料(數(shù)據(jù))及設(shè)計(jì)技術(shù)要求:
1.吊耳加強(qiáng)板零件圖
2.生產(chǎn)綱領(lǐng):中等批量
3.要求完成零件的沖壓工藝分析和沖壓工藝規(guī)程的編制。
1)要求編制吊耳加強(qiáng)板零件沖壓工藝
2)完成吊耳加強(qiáng)板成形模設(shè)計(jì)
III、畢 業(yè)設(shè)計(jì)(論文)工作內(nèi)容及完成時(shí)間:
1.收集有關(guān)資料,撰寫(xiě)開(kāi)題報(bào)告; 第1周——第2周
2.英文翻譯(6000實(shí)詞以上) 第3周
3.繪制吊耳加強(qiáng)板沖件圖, 第4周——第5周
4.編制吊耳加強(qiáng)板沖壓成形工藝規(guī)程; 第6周——第7周
5.繪制吊耳加強(qiáng)板成形模總裝圖及零件圖; 第8周——第10周
6.撰寫(xiě)畢業(yè)設(shè)計(jì)說(shuō)明書(shū)(論文) 第11周——第12周
7.畢業(yè)設(shè)計(jì)審查,畢業(yè)答辯。 第13周
Ⅳ 、主 要參考資料:
1.《沖模設(shè)計(jì)手冊(cè)》編寫(xiě)組.沖模設(shè)計(jì)手冊(cè).北京:沖模設(shè)計(jì)手冊(cè),1995
2.陳為國(guó).吊耳加強(qiáng)板沖壓工藝及沖模設(shè)計(jì).模具制造,2002.6
3.王新華,袁聯(lián)富編.沖模結(jié)構(gòu)圖冊(cè).北京:機(jī)械工業(yè)出版社,2003
4.羅益旋.沖壓新工藝新技術(shù)及模具設(shè)計(jì)實(shí)用手冊(cè). 銀聲音像出版社,2004
5. GB2851~2875《冷沖?!穱?guó)家標(biāo)準(zhǔn)
航空工程系 系 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 專業(yè)類 0781053 班
學(xué)生(簽名):
填寫(xiě)日期: 2011 年 3 月 1 日
指導(dǎo)教師(簽名):
助理指導(dǎo)教師(并指出所負(fù)責(zé)的部分):
航空工程系 系主任(簽名)
附注:任務(wù)書(shū)應(yīng)該附在已完成的畢業(yè)設(shè)計(jì)說(shuō)明書(shū)首頁(yè)。
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Cost Savings for Mold Materials: Consider the Details
Ways to reduce costs that are not related to the price per pound of the mold material.
By Patricia Miller
Choosing the right tooling material for plastic molding is becoming ever more difficult. In light of intense competition, as well as the cost of raw materials, which is driving the price of materials for molds up, it becomes increasingly more important to be selective in the choice of mold materials. There are things that can be done to help the moldmaker make the best selections for the application at hand, and these things are not simply looking at the price per pound.
But in order to do this, the moldmaker must consider other factors. This starts at the beginning of the moldmaking cycle, as the part to be manufactured is being proposed. The major areas to be considered in a mold design include:
· Size and complexity of the part or mold
· Production quantity required
· Type of plastic molding material required and its impact on the molding environment
· Mechanical requirements for the mold
· Physical property requirements for the mold (thermal conductivity, stiffness, thermal expansion)
· Stability requirement of mold during operation
Assembly issues (mating material criteria, coatability)
· Design features (sharp corners, thin sections, sealing methods)
· Surface condition requirements (polishing, texturing demands)
· Manufacturing methods (electro dis-charge machining, hard milling)
Cost savings can occur in all these areas, but for this discussion four areas of alloys will be addressed:
1. New high hardness matrix alloys
2. Thermally conductive alloys
3. Corrosion resistant materials
4. Prehardened alloys
In each case, the cost of the mold material is significantly outweighed by the benefits these alloys bring.
Figure 1. A mold for plastic injection molded electric motor rotors, made of 30 percent glass-filled Polyamide. Mold material has, to date, increased the life of the mold over 20 percent, eliminating mold repairs and refurbishment. Figures courtesy of Bohler-Uddeholm Corporation.
1. High Hardness Matrix Alloys
In an exciting development for mold materials, there are now tool steel grades available that can replace S7, H13 and with coating replace A2, D2 and M2 types where wear resistance is required. But the advantage that these grades bring is that they can be used from 50 HRC up to 62 HRC, and are weldable, polishable to high levels, texturable and are coatable when even higher wear resistance is required.
Figure 2. The relationship of highly conductive alloys, thermal conductivity versus hardness. The new Cu-Ni alloy, having hardness levels like that of P20, has higher thermal conductivity than other copper alloys and aluminum.
Very tough grades, these materials also provide an added advantage that thermal conductivity exceeds that of H13, hence cycle times can be reduced. These grades replace past cold work grades that could only achieve their mechanical properties by low temperature tempers, which did not permit good weldability, nitriding or PVD coating above 400oF. Their high polishability and texturability is due to the excellent uniformity of the matrix from the use of high technology remelting processes.
An example of this is shown in Figure 1. An injection mold insert made of Polyamide plus 30 percent glass fiber, was manufactured from a chromium-molybdenum-vanadium alloyed tool steel. At 54-56 HRC, it has been running for over 7,700 pieces and is still running well. Premium H13 at 50-52 HRC began to wear and plastically deform at 6,000 pieces.
2.Thermally Conductive Alloys
Copper alloys have been available for several years to address the need for cycle time reduction and part reproducibility, and have been used particularly for cores where plastic residing times are highest. Copper-beryllium alloys are available in hardness ranges of 30-40 HRC. In addition, there is a copper-nickel alloy that can achieve hardness of 30 HRC, which is in the range of a typical P20. The advantage this grade brings is that its thermal conductivity exceeds that of other copper alloys in this hardness range, and also that of aluminum. This grade also is antigalling and corrosion resistant (see Figure 2).
Figure 3. Rough milling of the cavity; premium H13, 45 HRC.
3. Design and Stainless Alloys
It is time to reconsider stainless alloys. There are new stainless alloys whose benefits are clear: high polishability, with toughness levels in the range of Premium H13, up to 50-52 HRC. The fact that these alloys will maintain their corrosion resistance with minimal need for rework or repolishing over the life of the mold, and still provide a durable, high mechanical strength mold, is worth careful consideration.
Figure 4. Drilling of cooling channels; premium H13, 45 HRC
One area which has limited the life of stainless molds in the past has been the use of tapered pipe plugs. Heat treatment limitations, machining issues with devel-oping the threads, stresses generated in the threads following torquing, along with the corrosive conditions of dead zones—which create pitting attack on the stainless—can lead to cracking in these regions. New stainless alloys can minimize susceptibility to this along with plug designs that are available to handle hydraulic sealing issues without machining threads into the mold material.
4. Prehardened Mold Materials
Looking away from the steel cost to manufacturing technique, we now see the development of machining practices, which permit the customer to use grades that are prehardened to higher hardness ranges. It is now possible to machine grades like H13 at hardness levels in the range of 44-46 HRC, and in many cases even harder. The advantage this brings is that the steel can be prehardened, in a method that gives excellent properties because the cooling rates can be faster when less detail is in the mold, and cracking susceptibility is less. The integrity of the steel increases, while the need for rough machining, stress relieving and prefinish machining is eliminated. This saves time and money, when usually at the stage when heat treatment is performed, time constraints are high. With these time constraints, corners get cut and heat treatment is not always done to optimize the property of the steel. Tempers may not all get done, and cooling rates are slowed down to permit less stock to be left on, because the moldmaker has less time to remove the extra stock needed for the movement that will take place from a good, rapid quench.
Figure 5. Finishing milling of cavity; premium H13, 45 HRC.
Some examples of how to machine a hardened H13 are given in Figures 3, 4 and 5.
Conclusion
There are many ways to reduce cost that are not related to the price per pound of the mold material. With the ultimate goal to provide the customer what they need in terms of part integrity and reliability, manufacturing a mold that will provide all of these things in a reasonable way requires a thorough review of the design criteria, manufacturing processes and production demands. New materials and methods are available that were not there the last time the mold was made, that can help minimize the overall cost of the mold.
附錄B
專業(yè)外文翻譯
節(jié)省模具材料費(fèi)用細(xì)則
降低成本的方式涉及的不光是每磅模具材料的價(jià)格。
作者:帕特麗夏 米勒
正確的選擇塑料模具材料變得越來(lái)越重要,在競(jìng)爭(zhēng)激烈的今天,原材料的成本升高使得模具的價(jià)格上漲,模具的材料的選擇就本的日益重要。有些東西可以幫助模具制造者們最好的選擇模具材料,并且這些東西不就簡(jiǎn)單的降低每磅模具材料的價(jià)格。
但是為了節(jié)省成本,模具制造商們肯定也會(huì)考慮到其他因素。首先要考慮的是模具制造的周期,當(dāng)要制造一個(gè)零件的時(shí)候,模具的主要設(shè)計(jì)的部分包括:
l 模具尺寸和復(fù)雜的模具型腔
l 產(chǎn)品質(zhì)量要求
l 塑料成型的類型和成型因素的影響
l 模具制造機(jī)械設(shè)備的要求
l 模具物理因素要求(傳熱性、硬度、熱膨脹)
l 生產(chǎn)過(guò)程中的穩(wěn)定性
裝配問(wèn)題(符合裝配原則,防繡)
l 設(shè)計(jì)原則(銳角轉(zhuǎn)角、避免薄壁、密封性好)
l 符合表面技術(shù)要求(拋光、粗糙度要求)
l 制造方式(電鍍、電火花加工、磨削加工)
每個(gè)階段都可以作到節(jié)省成本,但是有四個(gè)方面最為突出:
1. 新型高硬度鉍鉛錫銻合金
2. 熱導(dǎo)性良好的合金
3. 抗腐蝕材料
4. 預(yù)硬合金
無(wú)論以上那一種材料,作為模具材料,在節(jié)省成本方面的價(jià)值都是超過(guò)其他材料的方案。
例1. 電機(jī)轉(zhuǎn)子注塑模添加了30%的玻璃填充物聚酰胺,使得模具的壽命延長(zhǎng)了20%,減少模具修理和拋光工序。本例由Bohler-Uddeholm公司提供。
1. 高硬度鉍鉛錫銻合金
模具材料的發(fā)展令人樂(lè)觀,出現(xiàn)的許多新型的工具,鋼取代了S7,H13并且表面處理鋼代替了A2,D2,M2。這些新型的高級(jí)鋼的優(yōu)勢(shì)在于他們的硬度達(dá)到HRC50~HRC60,并且能夠焊接、精密磨削,組織致密和良好的耐磨性。
例2. 高熱導(dǎo)性鋼的導(dǎo)熱性與硬度的聯(lián)系。新型的銅鎳合金有著高硬度,達(dá)P20,比其他銅合金和鋁合金有著更好的導(dǎo)熱性。
那些超硬的材料,他們的優(yōu)勢(shì)在于熱導(dǎo)性超過(guò)H13。因此生產(chǎn)周期縮短。這些高級(jí)鋼替代了過(guò)去冷作模具鋼需要通過(guò)低溫回火才能達(dá)到所需機(jī)械性能,而且冷作模具鋼還不能焊接,擠壓或者400oF的PVD表面處理。高硬材料的優(yōu)良的表面特性來(lái)自于高技術(shù)的熔化處理得到的均勻的內(nèi)部晶體結(jié)構(gòu)。
例1能夠說(shuō)明以上觀點(diǎn)。注塑模加入30%的聚酰胺玻璃纖維,被制造成鉻鉬釩合金工具鋼。硬度在54~56HRC,它能夠工作7700次而毫物損傷,Premium H13的硬度在50~52HRC,在6000次的工作之后,塑件開(kāi)始發(fā)生變形。
2. 熱導(dǎo)合金鋼
銅合金的使用已經(jīng)有很多年了,一直以來(lái)都在努力縮短銅合金重新成型的周期,通過(guò)利用特殊核心技術(shù),塑料的成型次數(shù)最高。銅鈹和經(jīng)在硬度范圍30~40HRC范圍使用。另外銅鎳合金硬度能達(dá)30HRC,在P20的范圍之內(nèi)。此級(jí)別的合金的優(yōu)勢(shì)是熱傳導(dǎo)性和硬度范圍超過(guò)其他銅合金,也超過(guò)鋁合金的性能。此級(jí)別合金穩(wěn)定性、抗腐蝕性腔(參見(jiàn)例2)。
例3. 型腔磨削加工,優(yōu)質(zhì)H13,硬度45HRC
3. 不繡鋼的設(shè)計(jì)
我們必須重新審視不銹鋼的作用,很多新型的不繡鋼優(yōu)點(diǎn)突出,高的拋光能力,高的硬度等級(jí)可達(dá)H13,硬度HRC50~52。事實(shí)上這些合金保持著它們優(yōu)良的抗腐蝕性和最小的表面磨損,使的模具經(jīng)久耐用,這些優(yōu)點(diǎn)是值得我們認(rèn)真考慮的。
例4. 鉆孔加工冷卻水道;優(yōu)質(zhì)H13,45HRC。
這個(gè)區(qū)域會(huì)影響不繡鋼模具的壽命,過(guò)去通過(guò)異敬管插頭來(lái)降低影響。熱處理的限制螺紋的加工存在問(wèn)題,由于扭矩螺紋終止線存在壓力,死區(qū)表面在腐蝕環(huán)境中產(chǎn)生蝕斑,這些區(qū)域可能導(dǎo)致裂紋。新型的不銹鋼合金材料能最小優(yōu)化此不足,通過(guò)接頭的設(shè)計(jì)控制水封機(jī)構(gòu),而不需要在模具中加工螺紋。
4. 預(yù)硬模具材料
回望鋼的制造技術(shù)和價(jià)格的關(guān)系,我們現(xiàn)在看到加工技術(shù)的實(shí)際應(yīng)用,這使我們可以在更大的范圍應(yīng)用更硬的材料,預(yù)硬鋼。它可能加工硬度等級(jí)H13,44~46HRC的材料,甚至更硬的材料。這種材料的優(yōu)點(diǎn)在于可以先使之變硬,因?yàn)楸毁x予了這樣優(yōu)良的特性,所以它的冷卻速度很快,不會(huì)產(chǎn)生裂紋。粗加工的時(shí)候,鋼的完整性很重要,從而減少了很多修補(bǔ)和后處理的過(guò)程。這種節(jié)省時(shí)間和成本的方法,在熱處理的過(guò)程種是很重要的,時(shí)間的利用率高了。利用節(jié)省的時(shí)間可以優(yōu)化鋼的特性?;鼗鸬男Ч紱](méi)這么好,冷卻率的降低,使原料量降低,因?yàn)槟>咧圃煺吆苌贂?huì)花時(shí)間處理額外的原料,通過(guò)快速的淬火使原料變成產(chǎn)品。
例5.完成的型腔加工; 優(yōu)質(zhì)H13, 45 HRC 。
一些例子怎樣用機(jī)器制造被硬化的H13 給出在例3, 4 和5 。
結(jié)論
有許多方法降低生產(chǎn)成本,而不僅僅是與每磅模具材料費(fèi)用有關(guān)的方法。我們要提供給顧客的是最終的產(chǎn)品,按照顧客要求的完整的、穩(wěn)定的符合設(shè)計(jì)合理性的制造過(guò)程和產(chǎn)品要求的模具給顧客。新材料和方法的使用是的模具的制造比以前更出色,并且使模具的整體的費(fèi)用降為最低。
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