裝配圖電動(dòng)車遮雨外殼沖壓模設(shè)計(jì)(有cad圖)
裝配圖電動(dòng)車遮雨外殼沖壓模設(shè)計(jì)(有cad圖),裝配,電動(dòng)車,外殼,沖壓,設(shè)計(jì),cad
模具工業(yè)是國(guó)民經(jīng)濟(jì)的基礎(chǔ)工業(yè),是國(guó)際上公認(rèn)的關(guān)鍵工業(yè),工業(yè)發(fā)達(dá)國(guó)家稱之為“工業(yè)之母”。模具成型具有效率高,質(zhì)量好,節(jié)省原材料,降低產(chǎn)品成本等優(yōu)點(diǎn)。采用模具制造產(chǎn)品零件已成為當(dāng)今工業(yè)的重要工藝手段。模具在機(jī)械,電子,輕工,紡織,航空,航天等工業(yè)領(lǐng)域里,已成為使用最廣泛的工業(yè)化生產(chǎn)的主要工藝裝備,它承擔(dān)了這些工業(yè)領(lǐng)域中60%--80%產(chǎn)品零件,組件和部件的加工生產(chǎn)。“模具就是產(chǎn)品質(zhì)量”,“模具就是經(jīng)濟(jì)效益”的觀念已被越來(lái)越多的人所認(rèn)識(shí)和接受。在中國(guó),人們已經(jīng)認(rèn)識(shí)到模具在制造業(yè)中的重要基礎(chǔ)地位,認(rèn)識(shí)更新?lián)Q代的速度,新產(chǎn)品的開發(fā)能力,進(jìn)而決定企業(yè)的應(yīng)變能力和市場(chǎng)競(jìng)爭(zhēng)能力。在目前用薄鋼板制造發(fā)動(dòng)機(jī)罩蓋的傳統(tǒng)還是會(huì)持續(xù)相當(dāng)一段時(shí)間,所以有必要在鋼板的基礎(chǔ)上通過(guò)利用計(jì)算機(jī)軟件的功能分析零件的工藝性能(結(jié)構(gòu)合理,受力,是否容易沖出破面、、、),發(fā)現(xiàn)現(xiàn)有零件的不足之處,討論并確定改進(jìn)這些不足之處,進(jìn)而改善模具的設(shè)計(jì),改良沖裁方式;最終實(shí)現(xiàn)產(chǎn)品的改良,改善產(chǎn)品的力學(xué)性能,外觀,使用效果,和造價(jià)等等。沖壓加工是通過(guò)模具來(lái)實(shí)現(xiàn)的,從模具角度來(lái)看,模具生產(chǎn)技術(shù)水平的高低,已成為衡量一個(gè)國(guó)家產(chǎn)品制造水平高低的重要標(biāo)志,因?yàn)槟>咴诤艽蟪潭壬蠜Q定著產(chǎn)品的質(zhì)量、效益和新產(chǎn)品的開發(fā)能力?!澳>呤枪I(yè)生產(chǎn)的基礎(chǔ)工藝裝備”也已經(jīng)取得了共識(shí)。據(jù)統(tǒng)計(jì),在電子、汽車、電機(jī)、電器、儀器、儀表、家電和通信等產(chǎn)品中,60%~80%的零部件都要依靠模具成形。用模具生產(chǎn)制件所具備的高精度、高復(fù)雜程度、高一致性、高生產(chǎn)率和低消耗,是其他加工制造方法所不能比擬的。同時(shí),沖壓加工也創(chuàng)造了巨大的價(jià)值增值,模具是“效益放大器”,用模具生產(chǎn)的最終產(chǎn)品的價(jià)值,往往是模具自身價(jià)值的幾十倍、上百倍。目前全世界模具年產(chǎn)值約為600億美元,日、美等工業(yè)發(fā)達(dá)國(guó)家的模具工業(yè)產(chǎn)值已超過(guò)機(jī)床工業(yè),從1997年開始,我國(guó)模具工業(yè)產(chǎn)值也超過(guò)了機(jī)床工業(yè)產(chǎn)值。其中沖壓模具在所有模具(鍛造模、壓鑄模、注塑模等)中,無(wú)論從數(shù)量、重量或者是從價(jià)值上都位居榜首。
由此可見,板料沖壓加工及其模具制造技術(shù)對(duì)國(guó)民經(jīng)濟(jì)的發(fā)展已經(jīng)并將繼續(xù)作出重大的貢獻(xiàn)。隨著我國(guó)經(jīng)濟(jì)的發(fā)展,對(duì)這種生產(chǎn)技術(shù)的發(fā)展及專業(yè)技術(shù)人才的需求將與日俱增。因此,加強(qiáng)對(duì)板料沖壓加工及其模具制造技術(shù)的研究,具有重要的意義。
現(xiàn)狀和發(fā)展趨勢(shì):經(jīng)過(guò)了100多年的發(fā)展,目前小型汽車發(fā)動(dòng)機(jī)的罩殼的設(shè)計(jì)技術(shù)已經(jīng)相當(dāng)成熟的了,但是隨著各式各樣的小型發(fā)動(dòng)機(jī)的開發(fā),發(fā)動(dòng)機(jī)的前后罩也做了很大的改進(jìn)?,F(xiàn)在,對(duì)小型汽車發(fā)動(dòng)機(jī)的罩殼的改進(jìn)主要表現(xiàn)在對(duì)其構(gòu)造材料的改進(jìn);例如用樹脂基復(fù)合材料替代傳統(tǒng)的薄鋼板,用 RTM制造 發(fā)動(dòng)機(jī)水箱、隔熱罩、發(fā)動(dòng)機(jī)罩等等,由于用復(fù)合材料來(lái)取代原有金屬的發(fā)動(dòng)機(jī)殼體類零件,重量會(huì)有所減輕,且成本也將大大降低,對(duì)制造商而言,這個(gè)改進(jìn)創(chuàng)造了很大了利潤(rùn)空間,所以這方面的技術(shù)進(jìn)步還會(huì)持續(xù)相當(dāng)長(zhǎng)一段時(shí)間。就目前而言,我國(guó)沖壓模具還存在許多問(wèn)題,其中模具生產(chǎn)周期、質(zhì)量和數(shù)量仍舊是關(guān)鍵。與國(guó)際水平相比,一般來(lái)說(shuō),我國(guó)沖壓模具生產(chǎn)周期要比國(guó)外先進(jìn)水平長(zhǎng)、壽命約相差一倍、精度差距也較大。數(shù)量的不足主要反映在大型、精密、復(fù)雜、長(zhǎng)壽命模具上。存在這些問(wèn)題的主要原因是:1)行業(yè)結(jié)構(gòu)(如企業(yè)組織結(jié)構(gòu)、產(chǎn)品結(jié)構(gòu)、技術(shù)結(jié)構(gòu)和進(jìn)出口結(jié)構(gòu)等)不合理: 2)企業(yè)綜合素質(zhì)欠佳、設(shè)計(jì)制造水平較低、開發(fā)能力弱、管理較落后;3 )模具人才嚴(yán)重不足 ;4)資金投入不夠;5)專業(yè)化、標(biāo)準(zhǔn)化、商品化程度低,協(xié)作差:6)模具材料及相關(guān)技術(shù)落后;7)模具生產(chǎn)企業(yè)的效率和效益較低,等等。
柳州天隆機(jī)械有限公司所用的沖壓模具還比較落后,利用沖壓模具沖出的零件質(zhì)量也不是很高,經(jīng)常有起皺,尺寸和形狀精度不高,壽命短等缺陷。同時(shí),在排樣時(shí)的不合理更造成原材料的浪費(fèi)。這些因素?zé)o不影響著公司產(chǎn)品質(zhì)量和效益的提高。歸及以上原因主要是由于模具設(shè)計(jì)得不夠合理,考慮得不夠周全等所造成的。其次不合理的工藝設(shè)計(jì)也是造成零件質(zhì)量不高的原因。工藝設(shè)計(jì)是聯(lián)接產(chǎn)品設(shè)計(jì)與制造的橋梁和紐帶,合理的成形工藝設(shè)計(jì)是模具設(shè)計(jì)與制造的基礎(chǔ),也是決定零件能否順利成形的關(guān)鍵,它將直接關(guān)系到產(chǎn)品的質(zhì)量、成本、生產(chǎn)效率以及模具的使用壽命等方面。在現(xiàn)在這個(gè)科技突飛猛進(jìn)的時(shí)代里,模具設(shè)計(jì)技術(shù)同樣也是在快速的發(fā)展著。模具技術(shù)未來(lái)發(fā)展趨勢(shì)主要是朝信息化、高速化生產(chǎn)與高精度化發(fā)展。
而如今的市場(chǎng)經(jīng)濟(jì),競(jìng)爭(zhēng)又十分激烈,要想在市場(chǎng)中站得住腳,那么就必須不斷的提高自己設(shè)計(jì)模具的水平,使自己設(shè)計(jì)出來(lái)的沖壓模具更合理,沖出來(lái)的零件質(zhì)量,尺寸和形狀精度,壽命以及資源利用率都能得到大幅度的提高,進(jìn)而才能提高公司的效益和競(jìng)爭(zhēng)力。
1.2 選題背景
1.2.1 近年來(lái)沖壓成形工藝與理論的研究成果
近年來(lái),沖壓成形工藝有很多新的進(jìn)展,特別是精密沖裁、精密成形、精密剪切、復(fù)合材料成形、超塑性成形、軟模成形以及電磁成形等新工藝日新月異,沖壓件的精度日趨精確,生產(chǎn)率也有極大提高,正在把沖壓加工提高到高品質(zhì)的、新的發(fā)展水平。
由于引入了CAE,沖壓成形已從原來(lái)的對(duì)應(yīng)力應(yīng)變進(jìn)行有限元等分析而逐步發(fā)展到采用計(jì)算機(jī)進(jìn)行工藝過(guò)程的模擬與分析,以實(shí)現(xiàn)沖壓過(guò)程的優(yōu)化設(shè)計(jì)。在沖壓毛坯設(shè)計(jì)方面也開展了計(jì)算機(jī)輔助設(shè)計(jì),可以對(duì)排樣或拉深毛坯進(jìn)行優(yōu)化設(shè)計(jì)。
此外,對(duì)沖壓成形性能和成形極限的研究,沖壓件成形難度的判定以及成形預(yù)報(bào)等技術(shù)的發(fā)展,均標(biāo)志著沖壓成形以從原來(lái)的經(jīng)驗(yàn)、實(shí)驗(yàn)分析階段開始走上由沖壓理論指導(dǎo)的科學(xué)階段,使沖壓成形走向計(jì)算機(jī)輔助工程化和智能化的發(fā)展道路。
方案:作為沖壓件要大略了解它的沖壓性能的好或者差,用個(gè)人的經(jīng)驗(yàn)或者視覺的判斷就可以了,但是在要求量化的條件下,最好莫過(guò)于用機(jī)械相關(guān)的板料分析軟件;我使用DYNAFORM來(lái)對(duì)沖壓件分析。從分析的圖象的顏色可以判斷沖壓條件是否惡劣,給出的列表數(shù)據(jù)可以清楚得知道,拉伸的情況。依據(jù)它給出的信息,我們可以對(duì)沖壓件作出相應(yīng)的改進(jìn)。最后重點(diǎn)放在模具的設(shè)計(jì)上來(lái)。
大體步驟:
1.用CAE軟件(DYNAFORM)分析,并討論現(xiàn)有零件的工藝性(沖壓性能)
?2.改進(jìn)零件的部分外形,和加強(qiáng)筋分布。
?3.用FASTBLANK展料,并排樣,選出最佳排樣方案。
?4.進(jìn)行相關(guān)運(yùn)算,得出相關(guān)數(shù)據(jù)。描繪出大體輪廓。
?5.利用上面所得數(shù)據(jù),使用UG畫出模具3維圖(數(shù)模)。
6.利用上述數(shù)模 討論具體零件工藝和相關(guān)方案。
?7.利用 AUTOCAD或CAXA繪制模具相關(guān)部件2維圖。
?8.寫課題說(shuō)明書。
沖壓工藝過(guò)程的優(yōu)劣,決定了沖壓件制造技術(shù)的合理性、沖壓件的質(zhì)量和產(chǎn)品成本。因此必須對(duì)沖壓件進(jìn)行詳盡的工藝分析,分析沖壓件的結(jié)構(gòu)、性能及加工難易程度,確定科學(xué)的、合理的工序方案。并在保證產(chǎn)品的設(shè)計(jì)要求、滿足使用條件的情況下盡量減少工序,采用適宜的材料,盡量節(jié)約用料,選擇先進(jìn)且合理的加工技術(shù),力求生產(chǎn)工藝過(guò)程簡(jiǎn)單易行,以降低生產(chǎn)成本,提高經(jīng)濟(jì)效益。
模具CAE技術(shù)就是在設(shè)計(jì)制造模具之前,在計(jì)算機(jī)上模擬出沖壓件在模具中成形的真實(shí)過(guò)程,向用戶告知模具結(jié)構(gòu)設(shè)計(jì)、工藝條件狀況是否合理,并最終為用戶提供出最佳的模具設(shè)計(jì)工藝方案,可靠性達(dá)到80%以上。從而縮短模具設(shè)計(jì)與制造周期2/5(對(duì)于復(fù)雜模具而言),并提高模具質(zhì)量和產(chǎn)品合格率,進(jìn)而可大幅度降低制造成本,增強(qiáng)產(chǎn)品的市場(chǎng)競(jìng)爭(zhēng)力。
國(guó)內(nèi)模具與國(guó)外模具的差距
當(dāng)前,我國(guó)工業(yè)生產(chǎn)的特點(diǎn)是產(chǎn)品品種多、更新快和市場(chǎng)競(jìng)爭(zhēng)激烈。在這種情況下,用戶對(duì)模具制造的要求是“交貨期短”、“精度高”、“質(zhì)量好”、“價(jià)格低”。
而供需兩旺是近幾年來(lái)我國(guó)模具市場(chǎng)的總體表現(xiàn),2004年仍舊是這個(gè)格局。由于汽車、機(jī)電等工業(yè)的發(fā)展增幅回落,再加上原材料漲價(jià),能源緊張,電力供應(yīng)不足,資金周轉(zhuǎn)不暢和運(yùn)費(fèi)增加,所以2004年模具市場(chǎng)在供需兩旺的情況下,發(fā)展增幅也有所回落。2005年相比,預(yù)計(jì)要回落5個(gè)百分點(diǎn)以上。
在歐美,CAD/CAE/CAM已成為模具企業(yè)普遍采用的技術(shù)。在CAD方面,目前3D設(shè)計(jì)也達(dá)到了70%~89%。澳大利亞3D設(shè)計(jì)已達(dá)到60%,而我國(guó)只是剛剛起步。CAE技術(shù)在歐美應(yīng)用逐漸成熟。在沖模設(shè)計(jì)中應(yīng)用CAE軟件,模擬金屬變形過(guò)程,分析應(yīng)力應(yīng)變的分布,預(yù)測(cè)破裂、起皺和回彈等缺陷,我國(guó)只有少部分企業(yè)開始CAE技術(shù)的應(yīng)用。
DL圖(沖壓工藝過(guò)程圖)設(shè)計(jì)的過(guò)程中,在沖壓工藝分析、沖壓方向的確定和工序劃分方面我國(guó)與國(guó)外水平接近。但在工藝補(bǔ)充面的設(shè)計(jì)和產(chǎn)品數(shù)模的工藝處理方面還存在著較大的差距,如過(guò)拉延部分的設(shè)計(jì),回彈值的處理等方面國(guó)外具有豐富的經(jīng)驗(yàn),特別是在高精度轎車零件的工藝設(shè)計(jì)方面與國(guó)外相比仍存在著很大的差距。
高速切削是以高切削速度、高進(jìn)給速度和高加工質(zhì)量為主要特征的加工技術(shù)。在國(guó)外已是比較成熟的技術(shù),型面加工精度≤0.05mm,不需要研合間隙。修邊模刃口間隙由機(jī)加工保證;鉗裝不需要研配間隙,加工后可直接裝配合模。而國(guó)內(nèi)的模具鉗工工作量仍較大。
國(guó)內(nèi)的加工機(jī)床性能基本與國(guó)外設(shè)備相當(dāng),但在NC技術(shù)參數(shù)方面,走刀路徑、方式及技術(shù)的設(shè)計(jì)方面仍存在著差距。
另外在模具制造周期、質(zhì)量方面和標(biāo)準(zhǔn)化程度方面也存在著較大的差距。
第二章 沖壓工藝過(guò)程設(shè)計(jì)
沖壓工藝過(guò)程的優(yōu)劣,決定了沖壓件制造技術(shù)的合理性、沖壓件的質(zhì)量和產(chǎn)品成本。因此必須對(duì)沖壓件進(jìn)行詳盡的工藝分析,分析沖壓件的結(jié)構(gòu)、性能及加工難易程度,確定科學(xué)的、合理的工序方案。并在保證產(chǎn)品的設(shè)計(jì)要求、滿足使用條件的情況下盡量減少工序,采用適宜的材料,盡量節(jié)約用料,選擇先進(jìn)且合理的加工技術(shù),力求生產(chǎn)工藝過(guò)程簡(jiǎn)單易行,以降低生產(chǎn)成本,提高經(jīng)濟(jì)效益。
模具CAE技術(shù)就是在設(shè)計(jì)制造模具之前,在計(jì)算機(jī)上模擬出沖壓件在模具中成形的真實(shí)過(guò)程,向用戶告知模具結(jié)構(gòu)設(shè)計(jì)、工藝條件狀況是否合理,并最終為用戶提供出最佳的模具設(shè)計(jì)工藝方案,可靠性達(dá)到80%以上。從而縮短模具設(shè)計(jì)與制造周期2/5(對(duì)于復(fù)雜模具而言),并提高模具質(zhì)量和產(chǎn)品合格率,進(jìn)而可大幅度降低制造成本,增強(qiáng)產(chǎn)品的市場(chǎng)競(jìng)爭(zhēng)力。
隨著現(xiàn)代生產(chǎn)制造的需要,新產(chǎn)品開發(fā)設(shè)計(jì)、制造的質(zhì)量和周期已成為企業(yè)在市場(chǎng)經(jīng)濟(jì)中能夠生存發(fā)展的重要決定性因素之一。計(jì)算機(jī)輔助設(shè)計(jì)(CAD)及制造(CAM)技術(shù)的推廣應(yīng)用,不僅將產(chǎn)品開發(fā)的設(shè)計(jì)者們從繁重的手工制圖方式中解脫出來(lái),同時(shí),對(duì)加工制造業(yè)而言應(yīng)該是一次巨大的革命性飛躍。然而,在并行工程CE (ConcurrentEngineering)的概念提出和應(yīng)用前,產(chǎn)品的CAD /CAM/CAE/CAPP由于分屬不同部門的工作內(nèi)容,產(chǎn)品的設(shè)計(jì)、制造、分析是在自上而下的串行設(shè)計(jì)中完成的,很顯然,針對(duì)并行設(shè)計(jì),前者在整個(gè)設(shè)計(jì)過(guò)程中受到不能及時(shí)更新的約束,很難做到產(chǎn)品開發(fā)制造集成同步實(shí)現(xiàn),增加了開發(fā)周期和生產(chǎn)成本。公司完成的“國(guó)家863/CIMS主題”重大應(yīng)用項(xiàng)目并行工程, 通過(guò)在新產(chǎn)品開發(fā)CAD/CAM/CAE過(guò)程中的實(shí)施,體現(xiàn)了良好的應(yīng)用前景。其中,PRO/E三維設(shè)計(jì)系統(tǒng)在產(chǎn)品開發(fā)過(guò)程中沖壓模具的并行全相關(guān)參數(shù)化設(shè)計(jì)已得到很好的應(yīng)用。
近年來(lái),隨著計(jì)算機(jī)綜合應(yīng)用技術(shù)的迅速發(fā)展,計(jì)算機(jī)集成制造系統(tǒng)(CIMS)、并行工程(CE)、虛擬生產(chǎn)(VM)等一系列新技術(shù)將機(jī)械工程制造業(yè)帶進(jìn)了一個(gè)嶄新的生產(chǎn)過(guò)程模式。有關(guān)資料統(tǒng)計(jì)表明,我國(guó)在863/CIMS應(yīng)用推廣過(guò)程中,相關(guān)企業(yè)均獲得了明顯的經(jīng)濟(jì)和社會(huì)效益,在提高生產(chǎn)效率,降低成本、縮短產(chǎn)品周期、提高質(zhì)量方面的成
績(jī)尤為突出。
“并行工程”就其意義而言是一個(gè)復(fù)雜的系統(tǒng)過(guò)程,它解決如何有效的將產(chǎn)品開發(fā)設(shè)計(jì)、工藝準(zhǔn)備過(guò)程、制造、過(guò)程管理、經(jīng)營(yíng)銷售等過(guò)程合理的組織,實(shí)現(xiàn)獲得最佳的產(chǎn)品周期和成本。幾年來(lái),公司并行工程項(xiàng)目的啟動(dòng)和實(shí)施,在不同部門的協(xié)同應(yīng)用實(shí)施仍處于不斷探索驗(yàn)證的階段,其中,沖壓模具并行設(shè)計(jì)已經(jīng)基本形成了較為完善的過(guò)程框架,對(duì)于模具設(shè)計(jì)制造過(guò)程,并行設(shè)計(jì)的根本實(shí)現(xiàn)必須由核心CAD/CAM/CAE軟件的支持,作為并行工程的設(shè)計(jì)系統(tǒng)平臺(tái),公司引進(jìn)了美國(guó)PTC公司的PRO/ENGINEER作為CAD/CAM 軟件平臺(tái),而沖壓成形數(shù)值模擬分析則引進(jìn)了專業(yè)CAE分析系統(tǒng)DYNAFORM,在模具展開設(shè)計(jì)前和過(guò)程中,對(duì)于模具結(jié)構(gòu)設(shè)計(jì)意圖的關(guān)鍵要素利用PRO/E建模并通過(guò)標(biāo)準(zhǔn)數(shù)據(jù)格式提交給DYNAFORM 進(jìn)行計(jì)算分析,預(yù)測(cè)可行性干預(yù)改進(jìn)模具結(jié)構(gòu)相關(guān)參數(shù)。另外,在模具的制造上可以實(shí)現(xiàn)在PR0/E內(nèi)部的CAD/CAM無(wú)縫轉(zhuǎn)接,從而不僅可以完全體現(xiàn)模具設(shè)計(jì)意圖、避免工程圖紙的信息損失,還能夠大大縮短制造周期。PRO/ENGINEER在設(shè)計(jì)過(guò)程中可以利用參數(shù)設(shè)置、關(guān)系(Relations)、參考(Reference)管理實(shí)現(xiàn)全相關(guān)(Dependency)參數(shù)化設(shè)計(jì),換言之,在模具設(shè)計(jì)的過(guò)程中,設(shè)計(jì)產(chǎn)品的任何變化都將傳遞到模具所有相關(guān)的結(jié)構(gòu)件上并按照結(jié)構(gòu)設(shè)計(jì)意圖自動(dòng)更新。這大大提高了模具設(shè)計(jì)的效率,支持設(shè)計(jì)的反復(fù)性,高效率的進(jìn)行設(shè)計(jì)更新。PRo/ENGINEER提供了一套方法和各種工具構(gòu)成了一個(gè)相對(duì)完善的Top-Down Design的環(huán)境,Top—Down Design是指在結(jié)構(gòu)設(shè)計(jì)中的一種組織方式,其實(shí),不單純?cè)赑Ro/E環(huán)境下,以往在手工及二維設(shè)計(jì)過(guò)程中也體現(xiàn)了它的宗旨。Top—Down Design的主題思想是以圍繞核心設(shè)計(jì)意圖進(jìn)行關(guān)聯(lián)式展開設(shè)計(jì)。模具并行設(shè)計(jì)的實(shí)現(xiàn)一般按以下6個(gè)步驟來(lái)完成:
(1)模具設(shè)計(jì)者參與提取產(chǎn)品設(shè)計(jì)過(guò)程中確定產(chǎn)品或原型產(chǎn)品的模型要素,接受或自行完成已經(jīng)具備最終產(chǎn)品全部特點(diǎn)的建模。
(2)對(duì)產(chǎn)品進(jìn)行工藝分析,以Top-Down De—sign方式規(guī)劃確定模具重要結(jié)構(gòu)件的層級(jí)骨架(Skeletions)組織設(shè)計(jì)過(guò)程。
(3)在Pro/E系統(tǒng)中圍繞產(chǎn)品沖壓加工建立核心組件模型,并根據(jù)工藝需要確定結(jié)構(gòu)參數(shù),轉(zhuǎn)換數(shù)據(jù)格式提交沖壓CAE分析軟件DYN 刪進(jìn)行可靠性分析計(jì)算。
(4)在Pro/E系統(tǒng)中進(jìn)行模具設(shè)計(jì)。由于準(zhǔn)備隨時(shí)接受來(lái)自設(shè)計(jì)部門的變更及分析結(jié)果的干預(yù)進(jìn)行設(shè)計(jì)更新,需要利用建模結(jié)構(gòu)、順序、參照控制、特征間關(guān)系、元件間關(guān)系、組件間關(guān)系有效的保證整個(gè)模型的可靠性,如當(dāng)產(chǎn)品局部變更時(shí),相應(yīng)凸凹模、定位元件、固定板、上下模板結(jié)構(gòu)特征等必須保證成功的再生(Regenerate)。
(5)模具結(jié)構(gòu)設(shè)計(jì)完成后,輸出二維工程圖?;诠こ虉D與三維建模的全相關(guān)性,無(wú)論在設(shè)計(jì)過(guò)程中還是在今后都可確保模具局部結(jié)構(gòu)變化后工程圖自動(dòng)及時(shí)準(zhǔn)確的更新。
(6)同時(shí)提交模具的CAM 部門進(jìn)行工藝分析及編程。Pro/E系統(tǒng)CAD/CAM 的無(wú)縫連接,使得NC程序同樣可以得到更新.
沖模在裝配前應(yīng)根據(jù)沖模的結(jié)構(gòu)特點(diǎn)和技術(shù)要求,確定合理的裝配順序和裝配方法。沖模裝配之后,必須在生產(chǎn)條件下進(jìn)行試沖,沖出的工件按沖壓零件產(chǎn)品圖或試樣進(jìn)行檢查驗(yàn)收。如果發(fā)現(xiàn)不合格者,必須對(duì)沖模進(jìn)行適當(dāng)?shù)恼{(diào)整和修理,然后再試沖,直到生產(chǎn)合格的沖件為止。在沖模工作一段時(shí)間后,可采用超前維修。沖模的受力只局限于刃口的附近在使用一段時(shí)間以后,刃口處會(huì)不可避免地出現(xiàn)不均勻磨損和磨損溝痕,如果提前維修,可避免因凸、凹模間隙不均勻而產(chǎn)生附加彎矩和防止磨損溝痕產(chǎn)生裂紋,以提高模具壽命。
實(shí)踐證明,并行參數(shù)化設(shè)計(jì)技術(shù)在工藝準(zhǔn)備過(guò)程中的應(yīng)用,大幅度降低了產(chǎn)品周期,增強(qiáng)了設(shè)計(jì)的可靠性,同時(shí)為企業(yè)取得了巨大的經(jīng)濟(jì)效益和社會(huì)效益??梢灶A(yù)見,計(jì)算機(jī)立用技術(shù)將在生產(chǎn)過(guò)程中發(fā)揮更力Ⅱ重要的作用,并已漸漸成為現(xiàn)代制造業(yè)的—個(gè)重要特征。
Mold industry is the foundation of the national economy; it is recognized as the key industry in the world; and it is also regarded as "the mother of the industry" in the developed countries. Molding has many advantages, such as high efficiency, good quality, economizing on raw materials, reducing the cost of the production. Manufacturing the components of the productions by molding now has become an important technological method in the industry. In the machinery, electronics, light industry, textile, aviation, aerospace and other industrial areas, molding has become the most widely used main technical equipment of the industrialized production, which undertakes the processing and production task of 60% - 80% of the product components, elements and parts in these industrial fields. The concepts that "Mold is the product quality" and "Mold is the economic-effect" have been realized and received by more and more people. In China, people have recognized the important foundation of the molding in the manufacturing industry and they have realized that the management of the crisis and the market competiveness of the enterprises depend on the speed of replacement, new product development capabilities. Currently the tradition of manufacturing the engine hood by the thin steel plates will still be last quite some time, so it is necessary to analysis the technological properties, such as the reasonable structure, the force, whether it is easy to break out the surface, on the basis of the steel plate by computer software, to find the shortcomings of the ready components, discuss and determine the improvement of these deficiencies and thus improve the mold design and the stamping method, and to realize eventually the product improvement on the mechanical properties, appearance, the results of the usage and the cost and so on. Stamping processing is achieved by the mold. From the point of mold, the level of mold production technology has become the important symbol of measuring that of the country's manufacturing, because on a large extent the mold determines the capability of product quality, effectiveness and new product development. People have known that "mold industry is the basis processes and equipment of the industrial production". According to the statistics, in the products of electronics, automobile, electrical machinery, electrical appliances, instruments, meters, home appliances and communications, 60% ~ 80% of the parts are shaped by the molds. The characteristics of high-precision, high-complexity, high-consistency, high-productivity and low-consumption, which are acquired by the mold production, are incomparable with the other manufacturing methods. In addiction, the stamping process can create great added value. The mold is "the amplifier of the value"; the value of the final production made by the mold is often higher than that of the own mold dozens, or even hundreds. Nowadays, the value of the global mold annual outputting is about 60 billion U.S. dollars, and the output value of the mold industry has surpassed that of the machine tool industry in Japan, the United States and the other industrialized countries. Since 1997, China's output value of the mold industry has also exceeded that of the machine tool industry. Among all the molds (forging mold, die casting mold, injection mold, etc.), no matter the quantity, weight or the value of the stamping die is on the top one.
Thus, sheet metal stamping and processing and the mold production technology have made and will continue make a great contribution to the development of the national economy. With the development of China’s economy, the needs to the technology development and the technical professionals will be rising. Therefore, it is significantly important to strength the research of sheet metal stamping and processing and the mold production technology.
Current Situation and Development Trends: After the 100 years’ development, it has already been mature that the design technology of the engine of the hood of the small-size vehicle. However, with the exploitation of the all kinds of small sized engine, a lot of improvements have been done on the front and the rear hood of the engines. In the current period, the improvements of the hood of the small-size automobile’s engine are mainly manifested in the improvement of the construction materials, for example, replace the traditional thin steel plate with the resin-based composite materials and make with the engine water tank, the heat shield and the engine cover, etc. by RTM. As with composite materials replace the original metal shell type of engine parts, the weight will be reduced, and the cost will be greatly reduced; for manufacturers, this creates a great deal of profit, so the technical progress is also will continue for a long period of time. As far as it goes, there are still many problems in the China’s stamping die, and among these problems, the mold production cycle, quality and quantity are still the keys. Compared to the international standards, in general, the productive cycle of China’s stamping die is longer, the lifespan is shorter twice and there is a wide gap of the accuracy. The lack of quantity is mainly reflected on the large-scale, sophisticated, complex, long-life mold. The main reasons of these problems are the following: 1) the irrational industry structure (such as enterprise organizational structure, product structure, technical structure and import and export structure, etc.) 2) the weakness of the comprehensive character of the enterprise, the level of design and production, the ability of development and the management; 3) the serious shortage of the qualified personnel; 4) the shortage of the capital; 5) the low level of the specialization, standardization and commercialization and the bad collaboration: 6) the outmoded mold materials and related skill; 7) the low efficiency and benefits of the mold manufacturing enterprises, etc..
The stamping dies used by Tian Long Machinery Company Ltd., Liuzhou still relatively fall behind, so the components made by the stamping dies are with the shortcomings that they are of low quality, low accuracy of the size and shape and short lifespan, and they often wrinkle. Additionally, the irrational nesting may lead to the waste of raw materials. The reasons above are mainly due to the unreasonable mold design and the incomplete consideration. What’s more, the unreasonable process design is the reason of the low quality of the components. Process design is the bridge and link between the production design and manufacture. Reasonable forming process design is the basis of mold design and manufacture, and it is also the key that whether the component can form smoothly; it is related directly to the quality, cost, efficiency of the production, and the mold’s lifespan and so on. In the present era, the technology developing rapidly, the technology of mold design is also in the fast developing. The tendency of the mold technology in the future is the development towards the information technology, high-speed production and precision of the development.
Nowadays, competition is very intense in the market economy. In order to prevail in the market, the level of the design must be continually improved so that the stamping dies are more reasonable and the quality, size, shape accuracy, lifespan and resource utilization of the components are can be greatly enhanced, which can improve the company's efficiency and competitiveness.
1.2 Background of the topic
1.2.1 The Research Results of the of Metal Forming Technology and Research Results in Recent Years
In recent years, stamping forming process there are many new advances, especially in precision stamping, precision molding, precision cutting, composite materials, forming, super plastic forming, soft-casting and the electromagnetic forming of new technology with each passing day, increasing the accuracy of precision stamping parts productivity is also greatly improved, is to improve the stamping process to high-quality, new level of development.
Since CAE is introduced, the stamping process has developed to computer simulation and analysis process from making finite element analysis by the pairs of stress and strain in order to achieve optimal design. What’s more, the computer-aided design has also been launched in the stamping blank design to draw on the blank layout to optimize the design.
The research on the performance of the metal stamping and forming and the limits of forming, as well as the determination on the difficulty of the stampings forming and the developing on the techniques of forming forecasting, shows that the stamping and forming begins to enter the scientific stage guided by the stamping theory from the stage of analyzing the original experience and experiments; these all help the technology of stamping and forming go to the development of stamping and intelligent computer-aided engineering.
Program: As a stamping press, its rough performance, good or bad, can be the judged by personal experience or vision, but under the conditions of requiring the quantization, people would better use the sheet metal analysis software associated with the mechanism; and I use DYNAFORM to analysis the stamping parts. The color of the images in the analysis can determine that the conditions of the pressing, and we can know clearly the stretching situation by the list of data. Based on information given, we can improve correspondingly the stampings. Finally we should focus on the mold design up.
General steps:
1. Analyzing by using CAE software (DYNAFORM), and discussing the manufacturability of the existing parts (stamping performance)
2. Improving some parts shape, and strengthening the tendons distribution
3. Exhibition of materials by FASTBLANK, stock layout, and selecting the best layout program
4. Making calculations, getting the associated data and depicting the general outline
5. Draw the three-dimensional mold chart (DAC) by the use of the data above and UG
6. Discussing the specific parts technology and related programs according to the model
7. Drawing the two-dimensional map of the die of the related components by AUTOCAD or CAXA.
8. Writing the topic statement.
The pros and cons of the process of stamping process determine the rationality of the stamping parts manufacturing technology, the stamping parts quality and the cost of the production. Therefore the stamping parts must be made a thorough process analysis and by analyzing the structure, performance and the difficulty level of the stamping parts to choose the scientific and rational processes program. And to ensure the product design requirements, minimize the process, we could adopt the appropriate materials, save the materials, select the advanced and reasonable processing technology, and strive to the simple production process to reduce the production costs and improve the economic efficiency.
Mold CAE technology is the one which simulates the real process of the stamping die forming on the computer before the design and manufacture of molds, informs the user that whether the die structure design and the process conditions are reasonable and ultimately provides users with the best mold design process program. The reliability of this technology is more than 80%. By using the technology the design and manufacturing cycle can be reduced by 2 / 5 (for complex mold case) and improve the mold quality and product qualification rate which can significantly reduce the manufacturing cost and enhance the product market competition.
Gap between the Domestic and Foreign Mold
At present, the characteristics of China's industrial production are production variety, quick updates, and the fierce market competition. In this case, the requirements of the users for mold manufacturing are "the short delivery time", "high precision", "good quality", and "low prices".
That the supply and demand are both booming is the general display of China’s mold market in recent years, and in 2004 this pattern remains. As the growth rate of the automotive, mechanical and electrical industries drops, the price of the raw material rises, the energy and the electricity is in the shortage, the capital is not enough to go round and the transportation expense is on the rise, in 2004 the growth rate of the mold market falls back, although the supply and demand condition is flourishing. The condition in 2005 is expected to be down 5 percentage points compared to 2004.
In Europe and the United States, CAD / CAE / CAM have become a widely used technology in the mold enterprise. Presently the mature level of the 3D design of CAD has reached 70% ~ 89%, and Australian 3D design 60%, while China is only just on the beginning. The Application of CAE technology in Europe and the United States has been mature. In China, only few enterprises put CAE technology which can simulate of metal deformation process, analyze the distribution of stress and strain to predict rupture, forecast the defects such as cracking, wrinkling and springback in the use during the stamping die design.
In the DL Chart (stamping process diagram) design process, the stamping process analysis, the choosing of the direction of stamping and the division of the processes are close to those of foreign countries. However, there is a wide gap on the design of the additional surface in process and product processing, for example,
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