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冷沖模具使用壽命的影響及對策
沖壓模具概述
沖壓模具--在冷沖壓加工中,將材料(金屬或非金屬)加工成零件(或半成品)的一種特殊工藝裝備,稱為冷沖壓模具(俗稱冷沖模)。沖壓--是在室溫下,利用安裝在壓力機(jī)上的模具對材料施加壓力,使其產(chǎn)生分離或塑性變形,從而獲得所需零件的一種壓力加工方法。
沖壓模具的形式很多,一般可按以下幾個主要特征分類:
1.根據(jù)工藝性質(zhì)分類
?。?)沖裁模 沿封閉或敞開的輪廓線使材料產(chǎn)生分離的模具。如落料模、沖孔模、切斷模、切口模、切邊模、剖切模等。
(2)彎曲模 使板料毛坯或其他坯料沿著直線(彎曲線)產(chǎn)生彎曲變形,從而獲得一定角度和形狀的工件的模具。
(3)拉深模 是把板料毛坯制成開口空心件,或使空心件進(jìn)一步改變形狀和尺寸的模具。
(4)成形模 是將毛坯或半成品工件按圖凸、凹模的形狀直接復(fù)制成形,而材料本身僅產(chǎn)生局部塑性變形的模具。如脹形模、縮口模、擴(kuò)口模、起伏成形模、翻邊模、整形模等。
2.根據(jù)工序組合程度分類
(1)單工序模 在壓力機(jī)的一次行程中,只完成一道沖壓工序的模具。
(2)復(fù)合模 只有一個工位,在壓力機(jī)的一次行程中,在同一工位上同時完成兩道或兩道以上沖壓工序的模具。
(3)級進(jìn)模(也稱連續(xù)模) 在毛坯的送進(jìn)方向上,具有兩個或更多的工位,在壓力機(jī)的一次行程中,在不同的工位上逐次完成兩道或兩道以上沖壓工序的模具。
沖冷沖模全稱為冷沖壓模具。
冷沖壓模具是一種應(yīng)用于模具行業(yè)冷沖壓模具及其配件所需高性能結(jié)構(gòu)陶瓷材料的制備方法,高性能陶瓷模具及其配件材料由氧化鋯、氧化釔粉中加鋁、鐠元素構(gòu)成,制備工藝是將氧化鋯溶液、氧化釔溶液、氧化鐠溶液、氧化鋁溶液按一定比例混合配成母液,滴入碳酸氫銨,采用共沉淀方法合成模具及其配件陶瓷材料所需的原材料,反應(yīng)生成的沉淀經(jīng)濾水、干燥,煅燒得到高性能陶瓷模具及其配件材料超微粉,再經(jīng)過成型、燒結(jié)、精加工,便得到高性能陶瓷模具及其配件材料。本發(fā)明的優(yōu)點(diǎn)是本發(fā)明制成的冷沖壓模具及其配件使用壽命長,在沖壓過程中未出現(xiàn)模具及其配件與沖壓件產(chǎn)生粘結(jié)現(xiàn)象,沖壓件表面光滑、無毛刺,完全可以替代傳統(tǒng)高速鋼、鎢鋼材料。
冷沖模具主要零件
冷沖模具是沖壓加工的主要工藝裝備,沖壓制件就是靠上、下模具的相對運(yùn)動來完成的。加工時由于上、下模具之間不斷地分合,如果操作工人的手指不斷進(jìn)入或停留在模具閉合區(qū),便會對其人身安全帶來嚴(yán)重威脅。
(一)模具的主要零件、作用及安全要求
1.工作零件凸凹模是直接使坯料成形的工作零件,因此,它是模具上的關(guān)鍵零件。凸凹模不但精密而且復(fù)雜,它應(yīng)滿足如下要求:
(1)應(yīng)有足夠的強(qiáng)度,不能在沖壓過程中斷裂或破壞.
?。?)對其材料及熱處理應(yīng)有適當(dāng)要求,防止硬度太高而脆裂。
2.定位零件定位零件是確定坯件安裝位置的零件,有定位銷(板)、擋料銷(板)、導(dǎo)正銷、導(dǎo)料板、定距側(cè)刀、側(cè)壓器等。設(shè)計定位零件時應(yīng)考慮操作方便,不應(yīng)有過定位,位置要便于觀察,最好采用前推定位、外廓定位和導(dǎo)正銷定位等。
3.壓料、卸料及出料零件壓料零件有壓邊圈、壓料板等。
壓邊圈可對拉延坯料加壓邊力,從而防止坯料在切向壓力的作用下拱起而形成皺褶。壓料板的作用是防止坯料移動和彈跳。頂出器、卸料板的作用是便于出件和清理廢料。它們由彈簧、橡膠和設(shè)備上的氣墊推桿支撐,可上下運(yùn)動,頂出件設(shè)計時應(yīng)具有足夠的頂出力,運(yùn)動要有限位。卸料板應(yīng)盡量縮小閉合區(qū)域或在操作位置上銑出空手槽。暴露的卸料板的四周應(yīng)設(shè)有防護(hù)板,防止手指伸入或異物進(jìn)入,外露表面棱角應(yīng)倒鈍。
4.導(dǎo)向零件導(dǎo)柱和導(dǎo)套是應(yīng)用最廣泛的一種導(dǎo)向零件。其作用是保證凸凹模在沖壓工作時有精確的配合間隙。因此,導(dǎo)柱、導(dǎo)套的間隙應(yīng)小于沖裁間隙。導(dǎo)柱設(shè)在下模座,要保證在沖程下死點(diǎn)時,導(dǎo)柱的上端面在上模板頂面以上最少5至10毫米。導(dǎo)柱應(yīng)安排在遠(yuǎn)離模塊和壓料板的部位,使操作者的手臂不用越過導(dǎo)柱送取料。
5.支承及夾持零件它包括上下模板、模柄、凸凹模固定板、墊板、限位器等。
上下模板是冷沖模具的基礎(chǔ)零件,其他各種零件都分別安裝固定在上面。模板的平面尺寸,尤其是前后方向應(yīng)與制件相適應(yīng),過大或過小均不利于操作。
有些模具(落料、沖孔類模具)為了出件方便,需在模架下設(shè)墊板。這時墊板最好與模板之間用螺釘連接在一起,兩墊板的厚度應(yīng)絕對相等。墊板的間距以能出件為準(zhǔn),不要太大,以免模板斷裂。
6.緊固零件它包括螺釘、螺母、彈簧、柱銷、墊圈等,一般都采用標(biāo)準(zhǔn)件。冷沖模具的標(biāo)準(zhǔn)件用量較多,設(shè)計選用時應(yīng)保證緊固和彈性頂出的需要,避免緊固件暴露在表面操作位置上,防止碰傷人手和妨礙操作。
冷沖模具的發(fā)展
改革開放以來,隨著國民經(jīng)濟(jì)的高速發(fā)展,市場對冷沖模具的需求量不斷增長。近年來,冷沖模具工業(yè)一直以15%左右的增長速度快速發(fā)展,冷沖模具工業(yè)企業(yè)的所有制成分也發(fā)生了巨大變化,除了國有專業(yè)模具廠外,集體、合資、獨(dú)資和私營也得到了快速發(fā)展。
隨著與國際接軌的腳步不斷加快,市場競爭的日益加劇,人們已經(jīng)越來越認(rèn)識到產(chǎn)品質(zhì)量、成本和新產(chǎn)品的開發(fā)能力的重要性。而冷沖模具制造是整個鏈條中最基礎(chǔ)的要素之一,冷沖模具制造技術(shù)現(xiàn)已成為衡量一個國家制造業(yè)水平高低的重要標(biāo)志,并在很大程度上決定企業(yè)的生存空間。
近年許多冷沖模具企業(yè)加大了用于技術(shù)進(jìn)步的投資力度,將技術(shù)進(jìn)步視為企業(yè)發(fā)展的重要動力。一些國內(nèi)模具企業(yè)已普及了二維CAD,并陸續(xù)開始使用UG、Pro/Engineer、I-DEAS、Euclid-IS等國際通用軟件,個別廠家還引進(jìn)了Moldflow、C-Flow、DYNAFORM、Optris和MAGMASOFT等CAE軟件,并成功應(yīng)用于沖壓模的設(shè)計中。
以汽車覆蓋件模具為代表的大型沖壓模具的制造技術(shù)已取得很大進(jìn)步,東風(fēng)汽車公司模具廠、一汽模具中心等模具廠家已能生產(chǎn)部分轎車覆蓋件模具。此外,許多研究機(jī)構(gòu)和大專院校開展模具技術(shù)的研究和開發(fā)。經(jīng)過多年的努力,在模具CAD/CAE/CAM技術(shù)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)計制造周期等方面做出了貢獻(xiàn)。
雖然中國冷沖模具工業(yè)在過去十多年中取得了令人矚目的發(fā)展,但許多方面與工業(yè)發(fā)達(dá)國家相比仍有較大的差距。例如,精密加工設(shè)備在冷沖模具加工設(shè)備中的比重比較低;CAD/CAE/CAM技術(shù)的普及率不高;許多先進(jìn)的模具技術(shù)應(yīng)用不夠廣泛等等,致使相當(dāng)一部分大型、精密、復(fù)雜和長壽命冷沖模具依賴進(jìn)口。
隨著科學(xué)技術(shù)的不斷進(jìn)步,現(xiàn)代工業(yè)產(chǎn)品的生產(chǎn)日益復(fù)雜與多樣化,產(chǎn)品性能和質(zhì)量也在不斷提高,因而對冷沖壓技術(shù)提出了更高的要求.為了使冷沖壓技術(shù)能適應(yīng)各工業(yè)部門的需要,冷沖壓技術(shù)自身也在不斷革新和發(fā)展.冷沖壓技術(shù)的發(fā)展思路就是盡可能地完善和擴(kuò)充冷沖壓工藝的優(yōu)點(diǎn),克服其缺點(diǎn).在冷沖壓技術(shù)的發(fā)展過程中,應(yīng)注意以下幾方面:
(1)冷沖壓技術(shù)的發(fā)展過程中應(yīng)正確地確定工藝參數(shù)及冷沖模具工作部分的形狀與尺寸,提高沖壓件的質(zhì)量、縮短新產(chǎn)品試制周期,應(yīng)在加強(qiáng)沖壓成形理論研究的基礎(chǔ)上,使沖壓成形理論達(dá)到能對生產(chǎn)實(shí)際起指導(dǎo)作用,逐步建立起一套密切結(jié)合生產(chǎn)實(shí)際的先進(jìn)的工藝分析計算方法.國外已開始采用彈塑性有限元法對汽車覆蓋零件的成形過程進(jìn)行應(yīng)力應(yīng)變分析和計算機(jī)模擬,以預(yù)測某一工藝方案對零件成形的可能性和可能出現(xiàn)的問題。
(2)加快產(chǎn)品更新?lián)Q代,克服模具設(shè)計周期長的缺點(diǎn).應(yīng)大力開展模具計算機(jī)輔助設(shè)計和制造(CAD/CAM)技術(shù)的研究.在我國,目前要特別注意加強(qiáng)多工位級進(jìn)模CAD/CAM技術(shù)的研究。
(3)滿足大量生產(chǎn)需要以及減輕勞動強(qiáng)度.應(yīng)加強(qiáng)冷沖壓生產(chǎn)的機(jī)械化和自動化研究,使一般中、小件能在高速壓力機(jī)上采用多工位級進(jìn)模生產(chǎn),達(dá)到生產(chǎn)高度自動化,進(jìn)一步提高沖壓的生產(chǎn)率。
(4)擴(kuò)大冷沖壓生產(chǎn)的運(yùn)用范圍.使冷沖壓既適合大量生產(chǎn),也適合小批量生產(chǎn);既能生產(chǎn)一般精度的產(chǎn)品,也能生產(chǎn)精密零件.應(yīng)注意開發(fā)如精密沖裁(特別是厚料精沖)、高能成形、軟模成形、施壓和超塑性加工等新成形工藝,還要推廣簡易模(軟模和低熔點(diǎn)合金模)、通用組合模、數(shù)控沖床等設(shè)備的運(yùn)用。
此外,對沖壓板料性能的改進(jìn),模具新材料、模具新加工方法的開發(fā)也應(yīng)進(jìn)一步加強(qiáng)。
冷沖模具使用壽命的影響及對策
冷沖模具的使用壽命是以沖制出的工件數(shù)量來計算的。影響冷沖模壽命的因素很多。主要有模具結(jié)構(gòu)設(shè)計、制造模具所用凸模和凹模的材料、模具的熱處理質(zhì)量與表面強(qiáng)化、沖模零件的制造精度和冷沖壓材料的選取。除此之外,還有沖模的安裝、調(diào)整、使用以及維修等。
1.模具設(shè)計對壽命的影響
(1)排樣設(shè)計的影響排樣方法與搭邊值對模具壽命的影響很大,過小的搭邊值,往往是造成模具急劇磨損和凸、凹??袀闹匾颉墓?jié)約材料出發(fā),搭邊值愈小愈好,但搭邊值小于一定數(shù)值后,對模具壽命和剪切表面質(zhì)量不利。在沖裁中有可能被拉人模具問隙中,使零件產(chǎn)生毛刺,甚至損壞模具刃口,降低模具壽命。因此,在考慮提高材料利用率的同時,必須根據(jù)零件產(chǎn)量、質(zhì)量和壽命,確定排樣方法和搭邊值。
(2)凹模結(jié)構(gòu)的影響對容易產(chǎn)生應(yīng)力集中而開裂的凹模結(jié)構(gòu),可以采用組合結(jié)構(gòu)或鑲拼結(jié)構(gòu),以及預(yù)應(yīng)力結(jié)構(gòu),從而提高模具使用壽命。
(3)間隙的影響當(dāng)間隙過小時,壓縮擠壓利害,摩擦力增大,磨損增大,側(cè)面的磨損加劇,沖裁后卸料和推件時,材料與凸、凹模之間的摩擦還將造成刃口側(cè)面的磨損比端面的磨大大,同時也容易造成凸、凹模溫度很高,把金屬碎屑吸附在刃口側(cè)面,形成金屬瘤,使凸、凹模出現(xiàn)崩刃或脹裂現(xiàn)象。因此,過小的間隙對模具壽命極為不利。間隙太大,會增加凸模與凹模端面邊緣的集中應(yīng)力,致使壓應(yīng)力急劇增加,于是刃口邊很快屈服變形而失去棱角。因此又增加了沖裁力,進(jìn)而使刃口邊更快磨損,降低模具壽命。但為了減小凸、凹模的磨損,延長模具使用壽命,在保證沖裁件質(zhì)量的前提下,設(shè)計時適當(dāng)采用較大間隙是十分必要的。
(4)模具導(dǎo)向結(jié)構(gòu)對壽命的影響可靠的導(dǎo)向?qū)τ跍p小工作零件的磨損,避免凸、凹??袀欠浅S行У摹L貏e對無問隙或小問隙沖裁模、復(fù)合模和多工位級進(jìn)模更為重要。為提高模具壽命,必須根據(jù)工序和零件精度要求,正確選擇導(dǎo)向形式和導(dǎo)向精度,所選擇導(dǎo)向精度應(yīng)高于凸、凹模的配合精度。
(5)冷沖壓材料選取的影響冷沖壓材料應(yīng)滿足制件的設(shè)計要求和沖壓工藝要求,否則容易損傷模具,降低模具使用壽命。冷沖壓材料表面質(zhì)量不好,沖壓時制件易破裂,也易擦傷模具。冷沖壓材料塑性不好,變形量小,沖壓時制件易破裂,也易擦傷模具。另外,材料的厚度公差應(yīng)符合國家標(biāo)準(zhǔn)。因?yàn)橐桓睕_模適用于一定材料的厚度,成形、彎曲、翻邊、引伸模具的凸、凹模結(jié)構(gòu)間隙是直接根據(jù)材料厚度來確定的。所以材料厚度不均勻,會導(dǎo)致廢品產(chǎn)生和模具損壞。
2.模具材料對模具壽命的影響
模具材料對模具壽命的影響是模具材料性質(zhì)、化學(xué)成分、組織結(jié)構(gòu)、硬度和冶金質(zhì)量等的綜合反映。其中,材料性質(zhì)和熱處理質(zhì)量影響最為明顯。模具材料性質(zhì)對模具壽命的影響是很大的。如將同一種工件,使用不同的模具材料做彎曲試驗(yàn),試驗(yàn)結(jié)果:用9Mn2V材料,其壽命為5萬次;用Crl2MoV滲氮,其壽命可達(dá)40萬次。因此,在選用材料時,應(yīng)根據(jù)制件的批量大小,合理選用模具材料。模具工作零件的硬度對模具壽命的影響也很大。但并不是硬度愈高、模具壽命愈長。這是因?yàn)橛捕扰c強(qiáng)度、韌性及耐磨性等有密切的關(guān)系。有的沖模要求硬度高,壽命長。如采用T10鋼制造沖模,硬度為54~58HRC,只沖幾千次,制件毛刺就很大。如果將硬度提高到60~64HRC,則刃磨壽命可達(dá)2~3萬次。但如果繼續(xù)提高硬度,則會出現(xiàn)早期斷裂。有的沖模硬度不宜過高,如采用Crl2MoV制造凹模硬度為58~62HRC時,一般壽命為2—3萬件,失效形式是崩刃和開裂以及如果將硬度降到54~58HRC,壽命提高到5~6萬件,但硬度降低到50~53HRC會出現(xiàn)凹模刃口易磨鈍現(xiàn)象。由此可見,模具硬度必須根據(jù)材料性質(zhì)和失效形式而定。應(yīng)使硬度、強(qiáng)度、韌性及耐磨性、耐疲勞強(qiáng)度等達(dá)到特定沖壓工序所需要的最佳配合。
3.模具的熱處理質(zhì)量與表面強(qiáng)化對壽命的影響
模具的熱處理質(zhì)量對模具的性質(zhì)與使用壽命影響很大。實(shí)踐證明,模具工作零件的淬火變形與開裂,使用過程中早期斷裂,雖然與材料的冶金質(zhì)量、鍛造質(zhì)量、模具結(jié)構(gòu)及加工有關(guān),但與模具的熱處理關(guān)系更大。根據(jù)模具失效原因的分析統(tǒng)計,熱處理不當(dāng)引起的失效占50% 以上。實(shí)踐證明,高級的模具材料必須配以正確的熱處理工藝,才能真正發(fā)揮材料的潛力。模具工作零件表面強(qiáng)化處理的目的,是獲得外硬內(nèi)韌的效果,從而得到硬度、耐磨性、韌性、耐疲勞強(qiáng)度的良好配合。模具表面強(qiáng)化處理方法很多,表面處理的新技術(shù)工藝發(fā)展很快。除氮碳共滲和離子氮化、滲硼、滲鈮、滲釩、表面鍍硬鉻和電火花強(qiáng)化外,化學(xué)氣相沉積(CVD)和物理氣相沉積(PVD)已逐步采用。經(jīng)CVD和PVD處理后,模具表面覆蓋一層超硬物質(zhì),如TiC、TiN等。硬度極高、耐磨性、耐蝕性、抗黏合性很好,可提高模具壽命幾倍到幾十倍。
4.沖模零件的制造精度對模具壽命的影響
沖模制造的精度與使用壽命關(guān)系很大,特別是模具表面粗糙度對模具影響很大。如用Crl2MoV鋼制造落料模,如果表面粗糙度值R =1.6 m時,其壽命為3萬件左右。如經(jīng)精拋光,表面粗糙度值R =0.4 m,壽命可提高到4—5萬件。因此,對模具工作零件表面,一般都要經(jīng)過磨削、研磨、拋光等精加工和精細(xì)加工。
5.其他方面對模具壽命的影響
(1)壓力機(jī)的精度不高,也易使沖模損壞。
(2)沖模在壓力機(jī)上安裝的正確與否及操作者的技術(shù)水平高低,對模具壽命也有很大影響。
(3)沖模的保管和維護(hù)好壞,以及使用潤滑劑的情況,也影響模具使用壽命。
6.結(jié)語
在實(shí)際生產(chǎn)中,對于薄板沖模使用,很少出現(xiàn)非正常磨損的情況。但對于厚板沖模時則發(fā)現(xiàn)易出現(xiàn)非正常磨損,我們總是針對出現(xiàn)的問題進(jìn)行研究總結(jié)。因?yàn)橐桓崩錄_模,從設(shè)計、加工制造、裝配、調(diào)試到安裝、使用,都耗費(fèi)了眾多工時,同時沖模的凸、凹模使用的材料,大都是優(yōu)質(zhì)合金鋼。因此,沖模的成本都是比較高的。所以在生產(chǎn)中了解影響沖模壽命的因素及采取相應(yīng)的對策來指導(dǎo)生產(chǎn),具有重大的現(xiàn)實(shí)意義。
(2007屆)
本科生畢業(yè)設(shè)計(論文)資料
學(xué) 院、系:
機(jī)械工程學(xué)院
專 業(yè):
機(jī)械設(shè)計制造及其自動化
學(xué) 生 姓 名:
宋 璐
班 級:
機(jī)本0302
學(xué)號 26030213
指導(dǎo)教師姓名:
曾立平
職稱 教授
最終評定成績:
湖南工業(yè)大學(xué)教務(wù)處
二○○六年九月制
目 錄
第一部分 過程管理資料
一、畢業(yè)設(shè)計(論文)課題任務(wù)書 3
二、本科畢業(yè)設(shè)計(論文)開題報告 5
三、本科畢業(yè)設(shè)計(論文)進(jìn)展情況記錄 9
四、本科畢業(yè)設(shè)計(論文)中期報告 11
五、畢業(yè)設(shè)計(論文)指導(dǎo)教師評閱表 12
六、畢業(yè)設(shè)計(論文)評閱教師評閱表 13
七、畢業(yè)設(shè)計(論文)答辯及最終成績評定表 14
第二部分 設(shè)計說明書
八、設(shè)計說明書 15
- 18 -
2007屆
本科生畢業(yè)設(shè)計(論文)資料
第一部分 過程管理資料
2007屆畢業(yè)設(shè)計(論文)課題任務(wù)書
院(系):機(jī)械工程學(xué)院 專業(yè):機(jī)械設(shè)計制造及其自動化
指導(dǎo)教師
曾立平
學(xué)生姓名
宋璐
課題名稱
帶槽三角形固定板沖孔、沖槽、落料連續(xù)模設(shè)計
內(nèi)
容
及
任
務(wù)
一.設(shè)計內(nèi)容:
帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模設(shè)計要保證規(guī)定的生產(chǎn)效率和高質(zhì)量的沖壓件的同時,力求成本低模具壽命長。
1、方案分析與論證;
2、總體結(jié)構(gòu)設(shè)計;
3、零部件的結(jié)構(gòu)設(shè)計與計算。
二.設(shè)計任務(wù):
1、排樣圖的形式、主要尺寸和參數(shù);
2、模架、壓力機(jī)的結(jié)構(gòu)型式和主要尺寸的確定;
3、總體設(shè)計的分析與各部件的布置;
4、用AUTOCAD編制二維工程圖。
擬
達(dá)
到
的
要
求
或
技
術(shù)
指
標(biāo)
一.總體設(shè)計要求:
1、工作可靠,結(jié)構(gòu)簡單,裝卸方便,便于維修、調(diào)整;
2、盡量使用通用件,以便降低制造成本;
3、在保證功能和強(qiáng)度的要求下,盡量減少整備質(zhì)量。
二.說明書及圖紙要求:
1、設(shè)計說明書1份,達(dá)1.5萬字以上,且要符合規(guī)范要求:資料數(shù)據(jù)充分,標(biāo)明數(shù)據(jù)出處;計算過程詳細(xì)、完全;公式的字母含義應(yīng)標(biāo)明,有時還應(yīng)標(biāo)注公式的出處;內(nèi)容條理清楚,按步驟書寫;
2、設(shè)計圖樣全部用AutoCAD繪制,總的繪圖量達(dá)3張A0以上,其中:至少裝配圖1張。
進(jìn)
度
安
排
起止日期
工作內(nèi)容
07年1-3周
在校學(xué)習(xí),做前期準(zhǔn)備
第4周
搜集設(shè)計相關(guān)資料,整體規(guī)劃設(shè)計全過程,方案論證
第5-6周
排樣圖及相關(guān)參數(shù)的確定
第7-8周
模架及壓力機(jī)和模座的選定及參數(shù)的
第9-11周
繪制CAD二維工程圖
第12-13周
編寫設(shè)計說明書
第14周
通過指導(dǎo)老師驗(yàn)收
主
要
參
考
資
料
1、《冷沖壓工藝及模具設(shè)計》 劉心治主編重慶大學(xué)出版社
2、《沖壓工藝及模具設(shè)計》萬戰(zhàn)勝主編 鐵道出版社
3、《沖模設(shè)計》 吉林人民出版社
4、《實(shí)用沖壓技術(shù)》 機(jī)工出版社
5、《冷沖壓及塑料成型工藝與模具設(shè)計資料》 機(jī)工出版社
6、《模具設(shè)計與制造簡明手冊》 馮炳堯等編 上海出版社
7、《實(shí)用板金沖壓工藝圖集》 梁炳文主編 機(jī)械工業(yè)出版社
8、《沖壓工藝模具設(shè)計實(shí)用技術(shù)》 鄭家賢編 機(jī)械工業(yè)出版社
…
教研室
意見
簽名:
年 月 日
院(系)主管領(lǐng)導(dǎo)意見
簽名:
年 月 日
湖 南 工 業(yè) 大 學(xué)
本科畢業(yè)設(shè)計(論文)開題報告
(2007屆)
學(xué) 院、系:
機(jī)械工程學(xué)院
專 業(yè):
機(jī)械設(shè)計制造及其自動化
學(xué) 生 姓 名:
宋 璐
班 級:
機(jī)本0302
學(xué)號 26030203
指導(dǎo)教師姓名:
曾立平
職稱 教授
2007年3月12日
題目:我國沖壓模具前景
1.結(jié)合課題任務(wù)情況,查閱文獻(xiàn)資料,撰寫1500~2000字左右的文獻(xiàn)綜述。
本次的畢業(yè)設(shè)計是帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模的設(shè)計,課題的目的是讓我們在以往對模具設(shè)計學(xué)習(xí)的基礎(chǔ)上熟悉沖壓模具的設(shè)計流程;它既是一次檢閱,也是一次鍛煉,使我們系統(tǒng)地掌握沖壓模具設(shè)計的技術(shù),并與Auto CAD,Pro/E等模具設(shè)計軟件相結(jié)合,提高了我們的機(jī)械模具設(shè)計能力。
模具是現(xiàn)代工業(yè)的重要工藝設(shè)備,隨著科學(xué)技術(shù)的不斷進(jìn)步,它在國民經(jīng)濟(jì)中占有越來越重要的地位,發(fā)展前景十分廣闊。模具工業(yè)是技術(shù)密集型、資本密集型和投資密集型的產(chǎn)業(yè),就冷沖模具而言,在沖模設(shè)計與制造上,模具結(jié)構(gòu)與精度正朝著兩個方面發(fā)展:一是為了適應(yīng)高速、自動、精密、安全等大批量自動化生產(chǎn)的需要,沖模正向高效、精密、長壽命、多工位、多功能方向發(fā)展;另一方面,為適應(yīng)市場上產(chǎn)品更新?lián)Q代迅速的要求,各種快速成形方法和簡易經(jīng)濟(jì)沖模的設(shè)計與制造也得到了迅速的發(fā)展。同時,計算機(jī)技術(shù)、信息技術(shù)等先進(jìn)技術(shù)在模具技術(shù)中得到廣泛的應(yīng)用,使模具設(shè)計與制造水平發(fā)生了深刻的革命性的變化。目前最為突出的是模具CAD/CAE/CAM。在這方面,在這方面,國際上有許多應(yīng)用成熟的計算機(jī)軟件,我們不但能消化,應(yīng)用國外的有關(guān)軟件,少數(shù)單位還能自行開發(fā)或正在開發(fā)模具軟件,盡管其總體水平與國際上的還有差距,但它代表了我國模具技術(shù)的發(fā)展成果與發(fā)展方向。
模具是工業(yè)生產(chǎn)的基礎(chǔ)工藝裝備,模具又是“效益放大器”,用模具生產(chǎn)的最終產(chǎn)品的價值,往往是模具自身價值的幾十倍、上百倍。沖壓模具是其中重要的一種。模具的標(biāo)準(zhǔn)化和專業(yè)化生產(chǎn),已得到模具行業(yè)的廣泛重視。這是由于模具標(biāo)準(zhǔn)化是組織模具專業(yè)化生產(chǎn)的前提,而模具的專業(yè)化生產(chǎn)是提高模具質(zhì)量、縮短模具制造周期、降低成本的關(guān)鍵。我國已經(jīng)頒布了冷沖壓術(shù)語、冷沖模零部件的國家標(biāo)準(zhǔn)。沖模的模架等基礎(chǔ)零部件已專業(yè)化,商品化。但總的來說,我國沖模的標(biāo)準(zhǔn)化和專業(yè)化還是比較低的。主要是模具制造商對模具制造的認(rèn)識還不夠,對模具新技術(shù)的應(yīng)用力度不大,對在模具制造過程中模具標(biāo)準(zhǔn)設(shè)計還沒有足夠的認(rèn)識,還停留在老的手工制作又一有經(jīng)驗(yàn)的模具師傅帶隊的水平線上,試觀國外發(fā)達(dá)國家模具制造,把標(biāo)準(zhǔn)化的模具設(shè)計放在了最重要的位置上,其次是設(shè)備問題。性能良好的沖壓設(shè)備是提高沖壓生產(chǎn)技術(shù)水平的基本條件。高效率、高精度、長壽命的沖模需要高精度、高自動化的沖壓設(shè)備與之相匹配;為了適應(yīng)沖壓新工藝的需要,研制了許多新型結(jié)構(gòu)的沖壓設(shè)備;為了滿足新產(chǎn)品少批量生產(chǎn)的需要,沖壓設(shè)備朝多功能、數(shù)控方向發(fā)展;為提高生產(chǎn)率和安全生產(chǎn),應(yīng)用各種自動化裝置以及沖壓自動化生產(chǎn)線。
在帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模的設(shè)計中,落料是最重要的模具工序,它是把把剪裁或沖裁成一定形狀的平板毛坯利用某種特定的模具在沖裁力的作用下,使工件脫離毛胚而成零件;沖裁零件的尺寸精度一般可達(dá)IT8~14級,利用沖裁落料可以沖各種形狀的工件。
就三角形狀零件的落料來說,在沖裁性質(zhì)上與圓形零件的沖裁是相同的,區(qū)別就在于三角形沖裁件周邊的變形是不均勻的。在實(shí)際的沖裁過程中,簡單沖裁只是在直邊中部占很小的部分,而純粹的沖裁只是集中于圓角分角線的附近很小的區(qū)域。在二者中間的金屬變形情況則是相當(dāng)復(fù)雜的。它包括周邊的壓縮、豎向的伸長和零件上面壁部的略為變厚。在沖裁落料的時候,為了使得毛坯的變形過程進(jìn)行順利,得到口部平整的零件、保證零件的質(zhì)量,以及節(jié)省板料,就必需正確地確定毛坯的形狀和尺寸。如果毛坯的尺寸過大,則能使危險斷面上的沖裁力無謂地增大。這對提高變形程度和減少工序都不利;即使是毛坯的局部尺寸過大,這在沖裁過程中,過大的部分也會從變形區(qū)突出出去。不但使突出部分的變形減小,而且也使其臨近部分的板料變形比較困難。毛坯尺寸過大部分的變形程度減小必然使沖裁變形較多地集中到其余的部分上去。于是增加了沿毛坯周邊變形分布的不均勻程度,最后造成零件的壁厚不均勻,而且也容易引起變形過分集中部位的材料局部起皺,降低了沖件的質(zhì)量。由于在零件周邊上各個點(diǎn)金屬的切向壓縮變形和縱向拉深變形的數(shù)值都不同,其毛坯的形狀和尺寸的計算對于不同的尺寸比例時有很大的不同。在沖裁三角形件時,沖件的口部同樣也會出現(xiàn)高低不齊的現(xiàn)象。因此,在計算三角形零件的毛坯尺寸時,同樣也必須要加入修邊余量。
自從2001年加入世貿(mào)組織以來,我國經(jīng)濟(jì)發(fā)展迅速步入快車道階段,其中制造業(yè)的發(fā)展更是迅速。為此,世界著名的制造業(yè)跨國企業(yè)集團(tuán)紛紛落戶中國,不斷將中國發(fā)展成自己的研發(fā)和制造基地,提高自身產(chǎn)品的綜合競爭力,以角逐全球市場,致使中國的傳統(tǒng)制造業(yè)面臨前所未有的生存挑戰(zhàn)和發(fā)展機(jī)遇。中國的模具行業(yè)產(chǎn)值躋身于世界的第三位,但中國模具行業(yè)的質(zhì)量并不是世界上最好的,目前還趕不上德國和日本。但我們相信,中國不會因此而停頓,中國模具的發(fā)展,不僅僅是要量上考慮,更應(yīng)該要從質(zhì)上考慮,中國模具行業(yè)大有發(fā)展的空間。
3.工作進(jìn)度及具體安排。
3月8日~3月15日. 設(shè)計(論文)開題階段。
提出總體設(shè)計方案及草圖,填寫開題報告。
3月16日~5月16日. 設(shè)計(論文)初稿階段。
完成總體設(shè)計圖、部件圖、零件圖。
5月16日~5月26日. 中期檢查階段
中期檢查,編寫畢業(yè)設(shè)計說明書。
5月26日~6月2日. 畢業(yè)設(shè)計定稿階段。
圖紙修改、設(shè)計說明書修改、定稿,材料復(fù)查。
6月2日~6月6日.畢業(yè)答辯。
6月7日~6月19日.材料整理裝袋。
4.指導(dǎo)教師意見。
指導(dǎo)教師:
年 月 日
說明:開題報告作為畢業(yè)設(shè)計(論文)答辯委員會對學(xué)生答辯資格審查的依據(jù)材料之一,此報告應(yīng)在導(dǎo)師指導(dǎo)下,由學(xué)生填寫,將作為畢業(yè)設(shè)計(論文)成績考查的重要依據(jù),經(jīng)導(dǎo)師審查后簽署意見生效。 本科畢業(yè)設(shè)計(論文)進(jìn)展情況記錄
畢業(yè)設(shè)計(論文)題目: 帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模設(shè)計
班級: 機(jī)本0302 學(xué)號: 26030203 學(xué)生: 宋璐 指導(dǎo)教師: 曾立平
時 間
任務(wù)完成情況
指導(dǎo)教師意見
第 3 周
至
第 4 周
搜集設(shè)計相關(guān)資料,整體
規(guī)劃設(shè)計全過程,方案論證
指導(dǎo)教師簽名:
年 月 日
第 5 周
至
第 6 周
模具總體設(shè)計:模具形式、
尺寸參數(shù)和質(zhì)量參數(shù)的確定
指導(dǎo)教師簽名:
年 月 日
第 7 周
至
第 8 周
凸凹模設(shè)計:結(jié)構(gòu)方案
分析,主要參數(shù)確定
指導(dǎo)教師簽名:
年 月 日
注:教師監(jiān)督學(xué)生如實(shí)記錄畢業(yè)設(shè)計(論文)過程中根據(jù)《課題任務(wù)書》擬定的進(jìn)度與進(jìn)展情況以及畢業(yè)設(shè)計(論文)撰寫過程中遇到的問題和困難,并簽署意見。
第 9 周
至
第 11 周
繪制CAD二維工程圖
指導(dǎo)教師簽名:
年 月 日
第 12 周
至
第 13 周
編寫設(shè)計說明書
指導(dǎo)教師簽名:
年 月 日
第 13 周
至
第 14 周
圖紙修改、設(shè)計說明書
修改、定稿,材料復(fù)查。
指導(dǎo)教師簽名:
年 月 日
注:教師監(jiān)督學(xué)生如實(shí)記錄畢業(yè)設(shè)計(論文)過程中根據(jù)《課題任務(wù)書》擬定的進(jìn)度與進(jìn)展情況以及畢業(yè)設(shè)計(論文)撰寫過程中遇到的問題和困難,并簽署意見。
本科畢業(yè)設(shè)計(論文)中期報告
填表日期:2007年5月 16日
院(系)
機(jī)械工程學(xué)院
班級
機(jī)本0302
學(xué)生姓名
宋璐
課題名稱:帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模設(shè)計
課題主要任務(wù):
保證設(shè)計的模具有較高的的生產(chǎn)率和高質(zhì)量的沖壓件的同時,力求成本低、模具壽命長。設(shè)計的冷沖模必須保證操作安全、方便。沖模零件必須具有良好的工藝性,即制造裝配容易、便于管理。
1、 簡述開題以來所做的具體工作和取得的進(jìn)展或成果
開題以來做了大量相關(guān)的工作,首先對模具發(fā)展情況和市場進(jìn)行了認(rèn)真的分析思考,結(jié)合生產(chǎn)實(shí)際,市場對模具具有相當(dāng)?shù)男枨?,設(shè)計級進(jìn)模具有廣闊的市場前景。然后參觀見習(xí)了多家模具制造工廠,對模具制造的工藝流程有了一定的了解!然后我查閱了大量的相關(guān)的資料及模具設(shè)計手冊,開始對模具的總體進(jìn)行設(shè)計,形式的選擇,主要尺寸參數(shù)和質(zhì)量參數(shù)的確定。完成設(shè)計(論文)初稿。完成總體裝配圖、部件圖、零件圖。
2、 下一步的主要研究任務(wù),具體設(shè)想與安排
對前期工作進(jìn)行認(rèn)真細(xì)致的總結(jié),積極與贈教授展開研討,再次對總體方案進(jìn)行論證和驗(yàn)算,使其得到完善,優(yōu)化!認(rèn)真規(guī)范的編寫設(shè)計說明書,對初圖進(jìn)行修改,規(guī)范標(biāo)準(zhǔn)!總之,力爭達(dá)到如下的設(shè)計效果:工作可靠,結(jié)構(gòu)簡單,裝卸方便,便于維修、調(diào)整;盡量使用通用件,以便降低制造成本;在保證功能和強(qiáng)度的要求下,盡量減少整備質(zhì)量。
3、 存在的具體問題
主要問題是設(shè)計主要源自于理論,有關(guān)凸凹模和模架的結(jié)構(gòu)了解不是很清楚,所以對設(shè)計帶來了不少的麻煩!另外課題的難點(diǎn)是工件步矩較大以及標(biāo)準(zhǔn)件的選擇。除了凸模沖壓力過大需要進(jìn)行強(qiáng)度驗(yàn)算,其他部件均滿足要求。設(shè)計中始用擋料銷、活動擋料銷的設(shè)置導(dǎo)正銷的選擇都是
保證模具能正常生產(chǎn)的必要條件。
4、指導(dǎo)教師對該生前期研究工作的評價
指導(dǎo)教師簽名:
日 期:
畢業(yè)設(shè)計(論文)指導(dǎo)教師評閱表
院(系):機(jī)械工程學(xué)院
學(xué)生姓名
宋璐
學(xué) 號
26030203
班 級
機(jī)本0302
專 業(yè)
機(jī)械設(shè)計制造及其自動化
指導(dǎo)教師
姓 名
曾立平
課題名稱
帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模設(shè)計
評語:(包括以下方面,①學(xué)習(xí)態(tài)度、工作量完成情況;②檢索和利用文獻(xiàn)能力、計算機(jī)應(yīng)用能力;③學(xué)術(shù)水平或設(shè)計水平、綜合運(yùn)用知識能力和創(chuàng)新能力;)
是否同意參加答辯:
是□ 否□
指導(dǎo)教師評定成績
分值:
指導(dǎo)教師簽字: 年 月 日
畢業(yè)設(shè)計(論文)評閱教師評閱表
院、系:機(jī)械工程學(xué)院
學(xué)生姓名
宋璐
學(xué) 號
26030203
班 級
機(jī)本0302
專 業(yè)
機(jī)械設(shè)計制造及其自動化
課題名稱
帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模設(shè)計
評語:(對論文學(xué)術(shù)評語,包括選題意義;文獻(xiàn)利用能力;所用資料可靠性;創(chuàng)新成果及寫作規(guī)范化和邏輯性)
針對課題內(nèi)容給設(shè)計者(作者)提出3個問題,作為答辯時參考。
1.
2.
3.
評 分:
是否同意參加答辯
是□ 否□
評閱人簽名: 年 月 日
畢業(yè)設(shè)計(論文)答辯及最終成績評定表
院、系(公章):
學(xué)生姓名
宋璐
學(xué)號
26030203
班級
機(jī)本0302
答辯
日期
課題名稱
帶槽三角形固定板沖圓孔、沖槽、落料連續(xù)模設(shè)計
指導(dǎo)
教師
曾立平
成 績 評 定
分值
評 定
教師
1
教師
2
教師
3
教師
4
教師
5
小計
課題介紹
思路清晰,語言表達(dá)準(zhǔn)確,概念清楚,論點(diǎn)正確,實(shí)驗(yàn)方法科學(xué),分析歸納合理,結(jié)論嚴(yán)謹(jǐn),設(shè)計(論文)有應(yīng)用價值。
30
答辯
表現(xiàn)
思維敏捷,回答問題有理論根據(jù),基本概念清楚,主要問題回答準(zhǔn)確大、深入,知識面寬。
70
合 計
100
答 辯 評 分
分值:
答辯小組長簽名:
答辯成績a:
× %=
指導(dǎo)教師評分
分值:
指導(dǎo)教師評定成績b:
× %=
評閱教師評分
分值:
評閱教師評定成績c:
× %=
最終評定成績:
分?jǐn)?shù): 等級:
答辯委員會主任簽名:
年 月 日
說明:最終評定成績=a+b+c,三個成績的百分比由各院、系自己確定。
2007屆
本科生畢業(yè)設(shè)計(論文)資料
第二部分 設(shè)計說明書
Die Life of cold stamping die and mprovements
Overview of stamping die
Stamping Die - Stamping in the cold, the material (metal or non-metallic) processing into parts (or half) of a special technical equipment, called cold stamping die (commonly known as Die). Press - is at room temperature, using the die installed in the press to put pressure on the material to produce a separation or plastic deformation, and thus to obtain the necessary parts of a pressure processing method.
Stamping die in the form of many, the general categories according to the following main features:
1. According to the technical nature of
(1) Die along the closed or open contour the material are derived from mold. If blanking die, punch die, cut off the mold, cut mode, cutting mode, split mode, etc..
(2) bending mode to blank or blank sheet along a straight line (curved line) to bend, deform, and thus obtain a certain angle and shape of the workpiece in the mold.
(3) The drawing die is made of the blank sheet opening hollow, or hollow pieces of further changes to the shape and size of the mold.
(4) Die rough or semi-finished workpiece is convex according to plan, direct copy the shape of the die shape, the material itself, generate only local plastic deformation of the mold. Such as the bulging mode, reducing the die, expansion die, forming die rolling, flanging mold, plastic mold.
2. According to the degree classification process combination
(1) single process model in a press tour, just completed a die stamping process.
(2) composite model is only one station, in a press tour, at the same station at the same time to complete more than two or two die stamping process.
(3) Progressive Die (also known as the modulus of continuity) in the feeding direction, rough, with two or more of the station, at the press of a visit, work in different places on the completion of two or two successive Road over stamping die process.
Chong called cold stamping die Die-wide.
Cold stamping die is used in cold stamping die mold industry, and accessories required for high-performance structural ceramic materials, preparation methods, high-performance ceramic materials, molds and accessories from the zirconium oxide and yttrium aluminum powder increases, Pr element composition, Preparation is the solution of zirconia, yttria solution, praseodymium oxide solution, according to a certain percentage of alumina solution when mixed liquor, ammonium bicarbonate infusion, by co-precipitation synthesis of ceramic materials, molds and accessories needed for raw materials, reaction precipitate generated by the treatment, drying, calcining and accessories by high performance ceramic mold material superfine powder, and then after forming, sintering, finishing, they will have high-performance ceramic materials, molds and accessories. Advantages of this invention is the invention made of cold stamping dies and parts and long service life, the process does not appear in the press and its parts and stamping die bond generated the phenomenon of stamping surface is smooth, no glitches, can replace traditional high-speed steel, tungsten steel.
Die with the main parts
Die stamping tools is the main process equipment, stamping rely on the relative movement under the mold completed. Processing time because the upper and lower mold between the constant division and, if continued operation of the fingers of workers to enter or remain in the mold closed, there will certainly pose a serious threat to their personal safety.
(A) of the mold main parts, function and safety requirements
1. Working parts is a direct punch to blank forming the working parts, therefore, it is the key to mold parts. Punch not only sophisticated and complex, it should meet the following requirements:
(1) be of sufficient strength, can not be broken or destroyed during stamping.
(2) should be appropriate to its material and heat treatment requirements, to prevent too high hardness and brittle fracture.
2. Positioning parts positioning part is to determine the location of the parts installed blank, there are pins (board), gauge pin (plate), lead is sold, guide plate, knife set from the side, side pressure etc.. Design should be considered when positioning parts easy to operate and should not have had orientation, location to facilitate observation, preferably in the forward position, contouring to correct the pin location and positioning.
3. Binder, unloading and discharging parts binder components are blank holder, binder board.
Blank holder pressure can drawing blank holder force, thereby preventing billets under the action of the tangential pressure arch formed folds. The role of pressure plate to prevent movement and bounce blank. Top of the device, discharge board's role is to facilitate the pieces and clean up waste. Them by the spring, rubber and equipment, putting on the air-cushion support, can move up and down, knocking out pieces of the design should have enough top output, movement to the limited spaces. Stripper plate area should be minimized or closed position in the operating groove milling out empty-handed. Exposure of the stripper plate should have protection around the plate, to prevent finger inserted into or foreign objects inside, exposed surface edges should be blunt down.
4. Guide parts and guide sleeve guide pin is the most widely used part of a guide. Its role is to ensure punch the punching clearance when accurate match. Therefore, the guide posts, guide cover the gap should be less than the blanking clearance. Guide Post located next mold base, to ensure that the stroke bottom dead center, the lead column in the template on the face over the top for at least 5 to 10 mm. Guide columns should be arranged far away from the module and the pressure plate in the area, so the operator's arms do not get to take over the lead column material.
5. Supporting and clamping the upper and lower parts which includes templates, die handle, fixed plate punch, plate, stopper, etc..
Up and down the template is the basis of the cold die parts, other parts are respectively fixed at the top. Template plane size, especially around the direction to be compatible with the workpiece, too large or too small are not conducive to action.
Some molds (blanking, punching type mold) to the pieces of convenience, be set up under the mold plate. At this time the best and the template plate connected between the screw, the two plate thickness should be absolutely equal. Plate spacing out the pieces to be able to prevail, not too much, so as not to break the template.
6. Fastening parts which includes screws, nuts, springs, pins, washers, etc., are generally used standard parts. Die more with the amount of standard parts, design choice and flexibility should be tightened to ensure the top out of the need to avoid exposure to the surface fastener operating position, the staff and impede operation to prevent bumps.
Die with the development of
Since reform and opening, with the rapid development of the national economy, the market demand with the growing Die. In recent years, Die with the industry has been around 15% growth rate of the rapid development of industrial enterprises with ownership Die components also changed dramatically, in addition to the professional mold factory outside of state-owned, collective, joint ventures, wholly-owned and private has been a rapid development.
As with the accelerating pace of international integration, the increasing competition in the market, it has been increasingly recognized product quality, cost, and new product development capacities. The cold die manufacturing is the most basic elements of the chain, one of the cold die manufacturing technology to measure a country's manufacturing sector has become an important symbol of the level, and largely determine the viability of enterprises.
Die with enterprises to increase in recent years many technological advances for investment, technological progress will be seen as an important driving force for enterprise development. Some domestic enterprises have popularized the two-dimensional mold CAD, and gradually began to use UG, Pro / Engineer, I-DEAS, Euclid-IS and other international common software, individual manufacturers have also introduced Moldflow, C-Flow, DYNAFORM, Optris and MAGMASOFT etc. CAE software, and successfully applied in stamping die design.
A car cover mold as the representative of a large stamping die manufacturing technology has made great progress, Dongfeng Motor Corporation mold factory, mold manufacturers such as FAW mold center has been able to produce some car cover mold. In addition, many research institutions and universities to carry out technology research and development of mold. After years of effort, in the mold CAD / CAE / CAM technology has made remarkable progress; in improving quality and reducing mold die design and manufacturing cycle, and so contributed.
Although China Die with the industry over the past decade has made remarkable development, but in many ways compared with the industrialized countries there is still a large gap. For example, the precision machining equipment, processing equipment in Die with the relatively low proportion; CAD / CAE / CAM technology penetration is not high; many advanced mold technology not widely so, resulting in a considerable number of large, sophisticated, complex and long Die life with dependence on imports.
????With the continuous progress of science and technology, modern industrial production of increasingly complex and diverse, product performance and quality is ever increasing, thus the cold stamping technology put forward higher requirements. In order to adapt to the cold stamping technology industry needs, cold stamping technology itself also in innovation and development. cold stamping technology idea is to improve and expand as much as possible the advantages of the cold stamping process, to overcome its shortcomings. in the cold stamping technology development, should note the following aspects:
(1) cold stamping technology process parameters should be properly identified and Die with the work of some of the shape and size, to improve the quality of stamping parts and shorten the new product production cycle should be in strengthening the metal forming the basis of theoretical studies, to metal forming theory to practice can produce a direction, and gradually establish a close connection with the actual production of the advanced process of calculation. abroad have begun to use plastic finite element method, automobile parts forming process of the stress and strain analysis and computer simulation to predict the forming part of a process plan on the possibilities and potential problems.
(2) to accelerate product replacement, mold design to overcome the shortcomings of a long cycle. Should vigorously carry out computer-aided design and manufacture of molds (CAD / CAM) Research. In my country, paying particular attention to strengthening the multi-position progressive die CAD / CAM Technology.
(3) to meet the needs of mass production, and reduce labor intensity. Should strengthen cold stamping of mechanized and automated, so that the average, small pieces of high-speed presses in a multi-position progressive die production, production reached a high degree of automation to further improve stamping productivity.
(4) expand the scope of application of cold stamping production. So cold pressing both suitable for mass production, but also for small batch production; both the general accuracy of product production, but also can produce precision parts. Should pay attention to development such as fine blanking (especially thick material fine blanking), forming high-energy, soft mold forming, pressure and processing new superplastic forming process, but also promote the easy mode (soft mode and the low melting point alloy mold), Universal Hybrid model, the use of CNC punch press and other equipment.
In addition, the performance improvement of sheet metal stamping, mold new material, die development of new processing methods should be further strengthened.
Die with life and Countermeasures
Die with the life of the workpiece by punching out the number of terms. Many factors affect the life Die. There are die structure design, manufacture molds used in the punch and die materials, die quality and surface hardening heat treatment, precision die manufacturing parts and cold stamping materials selection. In addition, there are die installation, adjustment, use and maintenance.
1. Die Design on Life
(1) Layout design of layout methods and take the boundary value a great impact on the die life, too small to take the boundary value, often causing rapid wear and convex mold, die bite wounds on the. Starting from material savings, take the boundary value smaller the better, but take the edge is less than some value, the cut surface of the mold and the quality of life adversely. There will be left behind in the blanking die Q-gap were to produce spare parts glitch, or even damage the die edge, reduce die life. Therefore, consider increasing the material utilization of the same time, parts must yield, quality and life expectancy to determine the layout methods and take the boundary.
(2) die structure prone to stress concentration on the cracking of the die structure, composite structure can be used or mosaic structure, and prestressed structure to enhance the mold life.
(3) the impact of clearance when the gap is too small, compressed extrusion of interest, increased friction, increased wear, the wear side of aggravated discharge and push pieces after blanking time, materials and convex, the friction between die will cause wear and tear than the end edge on the side of the grinding much, but also easily lead to convex, concave mold temperature is high, the adsorption of metal debris in the side edge to form a metal tumor, so that male and female die chipping or expansion occurs crack phenomenon. Therefore, the gap is too small to Die Life very bad. Gap is too large will increase the punch and the die face the edge of the concentration of stress, resulting in a sharp increase in stress, so blade edge quickly lose angular yield deformation. Therefore, addition of blanking force, thereby enabling faster edge edge wear, reduce die life. But in order to reduce the male and female die wear, extending mold life, while ensuring quality of stamping pieces under the premise that larger space designed properly it is necessary.
(4) Die-oriented structure of the life of a reliable guide for the working parts reduce wear, prevent male and female die bite wound is very effective. In particular, non-small-Q gap Q gap or Die, compound die and multi-position progressive die even more important. To improve the die life, must be based on processes and the demand of precision, the correct choice-oriented form and orientation accuracy, the choice should be higher than the accuracy-oriented convex, concave mold with precision.
(5) the impact of cold stamping materials, cold stamping materials selected should meet the design requirements of workpieces and stamping process requirements, or easy to mold damage and reduce mold life. Poor surface quality of cold stamping, punching, cracking when the workpiece is also easy to scratch mold. Bad cold stamping plastic materials, deformation is small, easy to press when the workpiece rupture, but also easy to scratch mold. In addition, the material thickness tolerances shall comply with national standards. Die because of a certain thickness of material suitable for forming, bending, flanging, drawing die of the male and female die structure gap is directly determined by the thickness of the material. Therefore, uneven thickness, will result in waste generation and mold damage.
2. Die Die Life of
Die Die Life of a mold material properties, chemical composition, structure, hardness and comprehensive reflection of metallurgical quality. Among them, the material properties and heat treatment affect the quality of the most obvious. Mold material properties on the impact of die life is great. If the same workpiece, using a different mold material of the bending test, the test results: The 9Mn2V material, the life of 5 million; with Crl2MoV nitriding, the life of up to 40 million. Therefore, the choice of materials, the batch size should be based on workpiece, rational use of mold materials. The hardness of the die parts to Die Life a great impact. But not the higher hardness, longer die life. This is because the hardness and strength, toughness and abrasion resistance are closely related. Some die demands of high hardness, long life. Such as the use of T10 steel dies, hardness 54 ~ 58HRC, only washed thousands of times a burr on the workpiece great. If the hardness to 60 ~ 64HRC, the grinding life of up to 2 to 3 million. However, if continue to improve hardness, fracture occurs earlier. Some die hardness should not be too high, as the die manufacturing using Crl2MoV 58 ~ 62HRC hardness, the general life of 2-3 million, invalid form of chipping and cracking, and if the hardness down to 54 ~ 58HRC, life expectancy increased to 5 ~ 60 000, but decreased to 50 ~ 53HRC hardness appears easy to blunt the die edge phenomenon. Thus, mold hardness must be based on material properties and failure modes may be. Should enable the hardness, strength, toughness and wear resistance, resistance to fatigue strength needed to achieve a particular stamping process the best match.
3. The surface of the mold heat treatment to strengthen the quality and impact on life
Mold heat treatment the nature and quality of life of the mold a great impact. Practice shows that the die parts of the quenching distortion and cracking, early fracture during use, while the metallurgical and materials quality, forging quality, mold structure and process related, but related more to die of heat treatment. According to statistical analysis of failure causes of mold, heat treatment failure due to improper accounting for more than 50%. Practice shows that the mold material must be accompanied by high heat treatment process properly, can really play a material's potential. Parts surface hardening mold work purpose is to obtain the effect of external hard tough inside, so be hardness, wear resistance, toughness, good resistance to fatigue with. Many ways to die surface hardening, surface treatment technology of new technologies developed rapidly. In addition to Nitrocarburizing and ion nitride, boride, seepage niobium, vanadium permeability, hard chrome plated and spark strengthening, the chemical vapor deposition (CVD) and physical vapor deposition (PVD) has been gradually adopted. By CVD and PVD treatment, the mold surface covered with super-hard material, such as TiC, TiN, etc.. High hardness, wear resistance, corrosion resistance, adhesion is very good, can improve the die life several times to several times.
4. Manufacturing precision of the die parts of die life
Precision die manufacturing and life in it in particular, mold surface roughness on the mold a great impact. If using Crl2MoV steel blanking die, if the surface roughness value R = 1.6 m, its life span is about 30,000. Such as polished by the precision, surface roughness value R = 0.4 m, life can be increased to 4-5 million. Therefore, the working parts of the mold surface, the general must go through grinding, grinding, polishing and other finishing and fine processing.
5. Other aspects of the impact of die life
(1) Press the accuracy is not high, but also easy to make die damage.
(2) die in the press or not installed properly and the operator's technical level, on the tool life is also greatly affected.
(3) dies in the custody and maintenance of good and bad, and the use of lubricant condition also affects mold life