刷片沖孔落料工藝及模具設(shè)計(jì)【沖孔落料復(fù)合?!?/h1>
刷片沖孔落料工藝及模具設(shè)計(jì)【沖孔落料復(fù)合?!?沖孔落料復(fù)合模,刷片沖孔落料工藝及模具設(shè)計(jì)【沖孔落料復(fù)合模】,沖孔,工藝,模具設(shè)計(jì),復(fù)合
中期檢查表學(xué)生姓名學(xué) 號(hào)指導(dǎo)教師選題情況課題名稱刷片沖壓落料工藝及模具設(shè)計(jì)難易程度偏難適中偏易工作量較大合理較小符合規(guī)范化的要求任務(wù)書有無開題報(bào)告有無外文翻譯質(zhì)量?jī)?yōu)良中差學(xué)習(xí)態(tài)度、出勤情況好一般差工作進(jìn)度快按計(jì)劃進(jìn)行慢中期工作匯報(bào)及解答問題情況優(yōu)良中差中期成績(jī)?cè)u(píng)定:所在專業(yè)意見: 負(fù)責(zé)人: 2014 年 月 日設(shè)計(jì)說明書畢業(yè)設(shè)計(jì)題目:刷片沖孔落料工藝及模具設(shè)計(jì)系 部 專 業(yè) 班 級(jí) 學(xué)生姓名 學(xué) 號(hào) 指導(dǎo)教師 2014年 4 月 16 日刷片的沖壓工藝與模具設(shè)計(jì) 摘 要:我所學(xué)習(xí)的專業(yè)是模具設(shè)計(jì)與制造專業(yè),這次的畢業(yè)設(shè)計(jì)任務(wù)是刷片模具設(shè)計(jì)。該設(shè)計(jì)結(jié)合大學(xué)三年來所學(xué)習(xí)的專業(yè)知識(shí)和CAD軟件所設(shè)計(jì)出的一套模具。這套模具結(jié)合了制造廠家和生產(chǎn)廠家的實(shí)際情況綜合需求。本文首先簡(jiǎn)要的概述了模具設(shè)計(jì)在社會(huì)領(lǐng)域中的作用及其以后的發(fā)展方向,點(diǎn)明模具設(shè)計(jì)的重要意義。然后依據(jù)工件圖進(jìn)行工藝性分析,進(jìn)而確定了設(shè)計(jì)方案,計(jì)算出模具工作部分的尺寸,設(shè)計(jì)出工作零部件;然后依據(jù)設(shè)計(jì)要求選擇出各個(gè)標(biāo)準(zhǔn)零部件,然后設(shè)計(jì)出模具的總裝配圖。在設(shè)計(jì)中,最重要的就是設(shè)計(jì)方案的確定、坯料的計(jì)算和工作零部件的設(shè)計(jì),這是設(shè)計(jì)的關(guān)鍵,這些設(shè)計(jì)的正確與否直接關(guān)系到成本的高低和設(shè)計(jì)模具能否正常工作;在設(shè)計(jì)的最后,總結(jié)了自己的心得和體會(huì),并對(duì)我的指導(dǎo)老師表示感謝。通過次畢業(yè)設(shè)計(jì)使我不僅掌握了模具設(shè)計(jì)的一般流程,更學(xué)習(xí)到了好多課本上沒有學(xué)習(xí)到的知識(shí),使我受益非淺。關(guān)鍵詞:模具設(shè)計(jì),壓力機(jī),工藝性分析,模具結(jié)構(gòu)BRUSH PIECE OF THE STAMPINGPROCESS AND DIE DESIGNABSTRACT : The speciality of study of our institute is the mold design and speciality of making, the graduation project task this time is lining with a brush piece of mold design. Its time to design and combine the professional knowledge of study and a set of moulds that CAD software designed over the past three years of university. This set of moulds have accorded with the actual conditions integration requirement of manufacturer and manufacturer . This text the brief role in social field of mould of summary and developing direction afterwards at first, point out in the important meaning of mold design. Then carry on the craft to analyse according to the work piece picture , and then has confirmed the design plan , calculate out mould work some size , design the job spare part; Then choose each standard spare part according to the designing requirement , then design the total installation diagram of the mould . In the design, the most important one is sureness , calculation of the blank and design of the job spare part of the design plan , this is the key to designing, whether these ones that are designed involve directly or not correctly whether the level of the cost and design mould could work normally; At the end that is designed , have summarized ones own gains and experience , and express thanks for my counselor. Make me not merely grasp the general procedure of plastic mold design through graduation project once, study to the knowledge not learning to get on many textbooks even more, benefit me a great deal. KEY WORDS: mold design ,machine, craft analysis ,mould structure 目 錄 引 言.1 1 刷片沖壓工藝分析.2 1.1 零件分析.2 1.1.1 對(duì)工件的結(jié)構(gòu)工藝要求.2 1.1.2 工件的精度及毛刺.2 2 定工 藝方案.3 3 排樣設(shè)計(jì)與計(jì)算.4 3.1 搭邊.4 3.2 材料利用率.5 4 沖裁工藝力.6 4.1 計(jì)算沖裁力.6 4.2 壓力機(jī)的公稱壓力的選取.7 5 沖壓壓力中心.8 6 零件刃口尺寸計(jì)算.8 6.1 刃口尺寸計(jì)算的基本原則.8 6.2 刃口尺寸計(jì)算.9 6.3 凹模的外形輪廓尺寸.11 6.4 凸模設(shè)計(jì)計(jì)算.13 6.5 凸凹模計(jì)算.14 7 模具結(jié)構(gòu)設(shè)計(jì).15 8 沖壓模模具結(jié)構(gòu)件選取.16 9 模具零件制造工藝.17 9.1 模具零件的加工.17 9.2 沖壓工藝規(guī)程.17 10 模具的裝配.23 11 總 結(jié).24 致謝.25 參考文獻(xiàn).26 刷片沖孔落料工藝及模具設(shè)計(jì)引言零沖壓工藝規(guī)程是模具設(shè)計(jì)的依據(jù),而良好的模具結(jié)構(gòu)設(shè)計(jì)又是實(shí)現(xiàn)工藝過程的可靠保證,若沖壓工藝有所改動(dòng),往往會(huì)造成模具的返工,甚至報(bào)廢,沖裁同樣的零件,通??梢圆捎脦追N不同方法,工藝過程設(shè)計(jì)的中心就是依據(jù)技術(shù)上先進(jìn),經(jīng)濟(jì)上合理,生產(chǎn)上高效,使用上安全可靠的原則,使用上安全可靠的原則,使零件的生產(chǎn)在保證符合零件的各項(xiàng)技術(shù)要求的前提下達(dá)到最佳的技術(shù)效果和經(jīng)濟(jì)效益。設(shè)計(jì)沖壓工藝過程要從分析產(chǎn)品的零件圖入手,分析零件圖包括技術(shù)和經(jīng)濟(jì)兩個(gè)方面:(1)沖壓加工方法的經(jīng)濟(jì)性分析 沖壓加工方法是一種先進(jìn)的工藝方法,因其生產(chǎn)率高,材料利用率高,操作簡(jiǎn)單等一系列優(yōu)點(diǎn)而廣泛使用,由于模具費(fèi)用高,生產(chǎn)批量的大小對(duì)沖壓加工的經(jīng)濟(jì)性起著決定性作用。批量越大,沖壓加工的單件成本就越低,批量小時(shí),沖壓加工的優(yōu)越性就不明顯,這時(shí)采用其他方法制作 該零件可能會(huì)更有效果。(2)沖壓件的工藝性分析沖壓件的工藝性是指該零件在沖壓加工中的難易程度,在技術(shù)方面,主要分析該零件的形狀特點(diǎn),尺寸大小,精度要求和材料性能等因素是否符合沖壓工藝的要求,良好的工藝性應(yīng)保證材料消耗少,工序數(shù)目少,模具結(jié)構(gòu)簡(jiǎn)單,而且壽命長(zhǎng)產(chǎn)品質(zhì)量穩(wěn)定,操作簡(jiǎn)單,方便等。不論沖壓件的幾何形狀和尺寸大小如何,其生產(chǎn)過程一般都是從原材料剪切下料開始,經(jīng)過各種沖壓工序和其他必要的輔助工序加工出圖紙所要求的零件。對(duì)于某些組合沖壓件或精度要求較高的沖壓件,還需要經(jīng)過切削焊接或鉚接等加工才能完成。1 刷片沖壓工藝分析1.1 零件分析本設(shè)計(jì)是一個(gè)是由沖孔、落料工序制成的工件。該工件結(jié)構(gòu)簡(jiǎn)單,材料為20鋼,厚度為1.5mm,根據(jù)提供的零件圖,其數(shù)據(jù)如下:20鋼標(biāo)準(zhǔn):GB/T699-1988特性及適用范圍:強(qiáng)度比15號(hào)鋼稍高,很少淬火,無回火脆性。冷變形塑性高、一般供彎曲、壓延、彎邊等加工.材料名稱優(yōu)質(zhì)碳素結(jié)構(gòu)鋼如圖所示該零件材質(zhì)較軟、板料較薄、平直度要求較高的沖裁件,沖裁件的精度高,所以選用正裝復(fù)合模具1.1.1對(duì)工件的結(jié)構(gòu)工藝要求(1)工件的結(jié)構(gòu)形狀,在滿足裝配,使用性能和效果條件下,該工件的形狀是、簡(jiǎn)單有廢料排樣;(2)工件的外形是無尖角,在各直線或曲線的鏈接出有適宜的圓角過渡,有利于提高工件的質(zhì)量,與延長(zhǎng)模具使用壽命;(3) 工件沒有凸出或凹入部分,這工件有伸出懸臂和窄槽;(4)工件孔與孔的邊緣之間,孔的外邊緣與外形邊緣之間的直線寬度不能過小,不然會(huì)影響到模具零件的強(qiáng)度、工件的質(zhì)量、模具的結(jié)構(gòu)復(fù)雜性及使用壽命。1.1.2工件的精度及毛刺精度可以分為精密級(jí)與經(jīng)濟(jì)級(jí)兩種:(1)精密級(jí)是沖壓工藝技術(shù)上所允許的精度;(2)經(jīng)濟(jì)級(jí)是用經(jīng)濟(jì)手段達(dá)到的精度。還有對(duì)尺寸或配合精度要求很高的精密級(jí)高精度,則需要安排特殊的成型方法。毛刺,在普通沖裁中,由于凸凹模有一定的間隙存在,加上沖件材料的輕度,厚度模具的人口鋒利程度等,沖件的斷面真正的前切面質(zhì)疑剛接觸的吊扣的一小段距離,一般約為此阿里奧厚度的1/3-1/5或更少。其余部分是因撕裂而分離的。由于沖件一般具有塑性,所以在撕裂時(shí)就形成高低不等的毛刺,因此普通沖裁的毛刺是不可避免的。2 定工藝方案根據(jù)零件的結(jié)構(gòu),在沖裁部分工藝方案可以有以下幾種:方案一:采用落料、沖孔的復(fù)合模。復(fù)合模的特點(diǎn)是生產(chǎn)率高,沖裁件的內(nèi)孔與外緣的相對(duì)位置精度高,沖模的輪廓尺寸較小。但是復(fù)合模結(jié)構(gòu)復(fù)雜,制造精度要求高,成本高。復(fù)合模主要用于生產(chǎn)批量大、精度要求高的沖裁件。方案二:采用級(jí)進(jìn)模加工。級(jí)進(jìn)模比單工序模生產(chǎn)率高,減少了模具和設(shè)備的數(shù)量,工件精度較高,便于操作和實(shí)現(xiàn)生產(chǎn)自動(dòng)化。對(duì)于特別復(fù)雜后孔邊距較小的沖壓件,用簡(jiǎn)單模后復(fù)合模沖制有困難時(shí),可用級(jí)進(jìn)模逐步?jīng)_出。但是級(jí)進(jìn)模輪廓尺寸較大,制造較復(fù)雜,成本較高,一般適用于大批量生產(chǎn)小型沖壓件。綜合以上的二個(gè)方案,根據(jù)零件的結(jié)構(gòu)以及該零件是大批量生產(chǎn)的,因此選用方案一的復(fù)合模為佳。3排樣設(shè)計(jì)與計(jì)算根據(jù)材料的經(jīng)濟(jì)利益利用程度,排樣的方法為有廢料。據(jù)工件的形狀,確定采用無廢料排樣的方法是不可能做到的,但能采用有廢料和少?gòu)U料的排樣方法。3.1 搭邊排樣時(shí)沖裁件與沖裁件之間以及沖裁件與條料側(cè)邊之間留下的工藝余料稱為搭邊。搭邊值不能過大或過小。搭邊過大,浪費(fèi)材料;搭邊過小,起不到搭邊作用,材料可能被拉入凸、凹模之間的縫隙中,使模具刃口破壞。搭邊的合理數(shù)值:保證沖裁件質(zhì)量、模具壽命,保證自動(dòng)送料時(shí)不被拉彎、拉斷條件下允許的最小值。影響搭邊值的因素:板料厚度、材料種類、沖裁件大小、沖裁件的輪廓形狀等。條料是由板料(或帶料)剪裁下料而得,為保證送料順利,規(guī)定條料寬度B的上偏差為0,下偏差為負(fù)值(-)搭邊和條料寬度的確定:查沖壓工藝與模具設(shè)計(jì)(第二版)表2. 5. 2,確定零件沿邊a=2mm、零件之間a1=1.8mm,步距35.2mm。搭邊及排樣如圖1-1所示: 圖1-1 零件的搭邊及排樣方式查沖壓工藝與模具設(shè)計(jì)表214和215可取條料寬度公差。=0.5 ,則條料寬度: 3.2材料利用率一個(gè)步距內(nèi)材料利用率為: A是一個(gè)工件的面積mm2;N是一個(gè)進(jìn)距內(nèi)的工件的數(shù)量;B是條料寬度mm;S是進(jìn)距mm。選用350mm1000mm的鋼板,每張鋼板可剪裁為10條料(35mm1000mm),每張條料可沖20個(gè)工件,則材料總的利用率為 N是一張板上的工件的總的個(gè)數(shù)B是板料的寬度L是板料的長(zhǎng)度4沖裁工藝力4.1計(jì)算沖裁力沖裁力計(jì)算包括沖裁力、卸料力、推件力的計(jì)算:沖裁力:是指作用于凸模上的最大抗力,即圖2.13中的C點(diǎn)所對(duì)應(yīng)的力。沖裁力FP 如果視沖裁為純剪切變形,沖裁力可按下式計(jì)算: (K取1.3 ) 式中:FP 沖裁力; L沖裁件受剪切周邊長(zhǎng)度(mm); t沖裁件的料厚(mm); 材料抗剪強(qiáng)度(MPa),此例中零件的周長(zhǎng)為211.4mm,材料厚度1mm,紫銅的抗剪強(qiáng)度取190MPa,則沖裁該零件所需沖裁力為: 卸料力和推件力計(jì)算 模具采用彈性卸料裝置和推件結(jié)構(gòu),所以所需卸料力和推件力為: 卸料力P卸:從凸模上卸下板料/沖孔件所需的力; 推件力P推:從凹模內(nèi)向下推出落料件/廢料所需的力。 (1)卸料力FQ (2)推件力FQ1 公式中, FQ1是沖裁力 K卸料力系數(shù), 其值為取0.04 K1是推料力系數(shù) 其值為取0.05 N梗塞在凹模內(nèi)的制件或廢料的數(shù)量,N=h/t,h 是直刃口部分高度(mm),t為材 料厚度(mm)。4.2壓力機(jī)的公稱壓力的選取采用了彈壓卸料裝置和下出件的模具時(shí)經(jīng)查沖壓設(shè)計(jì)與模具設(shè)計(jì)中附錄A-1表的壓力機(jī)的主要技術(shù)參數(shù)可知,JH2316型號(hào)的壓力機(jī)。其一些主要的參數(shù)是最大閉合高度是Hmax = 220mm 最小的閉合高度是Hmin =175mm計(jì)算沖壓模閉合高度H:查沖模設(shè)計(jì)與制造實(shí)用計(jì)算手冊(cè)中的公式: 公式中:Hmax 壓力機(jī)的最大閉合高度(mm); Hmin 壓力機(jī)的最小閉合高度(mm); H 沖模的閉合高度(mm);220-5H 175+10 215H 185 所以沖模高度: H=210mm5沖壓壓力中心沖模對(duì)工件施加沖壓力的合力的中心稱沖壓壓力中心。所以遵循沖壓壓力中心原則:(1)對(duì)稱形狀的單個(gè)沖裁件,沖模的壓力中心就是沖裁件的沖孔中心;(2)工件形狀相同且分布位置對(duì)稱時(shí),沖模的壓力中心與零件的對(duì)稱中心相重合;(3)形狀復(fù)雜的零件,多孔沖模,級(jí)進(jìn)模的壓力中心可用解析法求出沖模壓力中心。零件外形為對(duì)稱件,中間的異形孔雖然左右不對(duì)稱,但孔的尺寸很小,左右兩邊圓弧各自的壓力中心距零件中心線的距離差距很小,所以該零件的壓力中心可近似認(rèn)為就是零件外形中心線的交點(diǎn)。因?yàn)樵摴ぜ菍?duì)稱形狀的單個(gè)沖裁件沖模的壓力中心就是沖裁件的沖孔中心。如圖1-2所示: 圖1-2 工件幾何形狀6零件刃口尺寸計(jì)算6.1刃口尺寸計(jì)算的基本原則沖裁件的尺寸精度主要取決與模具刃口的尺寸精度,模具的合理間隙也要靠模具刃口尺寸及制造精度來保證。正確確定模具刃口尺寸及制造公差,是設(shè)計(jì)沖裁模主要任務(wù)之一。從生產(chǎn)實(shí)踐中可以發(fā)現(xiàn): (1)由于凸、凹模之間存在間隙,使落下的料和沖出的孔都帶有錐度,且落料件的大端尺寸等于凹模尺寸,沖孔件的小端尺寸等于凸模的尺寸。 (2)在測(cè)量與使用中,落料件是以大端尺寸為基準(zhǔn),沖孔孔徑是以小端尺寸為基準(zhǔn)。 (3)沖裁時(shí),凸、凹模要與沖裁件或廢料發(fā)生摩擦,凸模愈磨愈小,凹模愈磨愈大,結(jié)果使間隙越來越大。 由此在決定模具刃口尺寸及其制造公差時(shí)需要考慮以下原則: (1)落料件尺寸由凹模尺寸決定,沖孔時(shí)的尺寸由凸模尺寸決定。故設(shè)計(jì)落料模時(shí),以凹模為基準(zhǔn),間隙取在凹模上;設(shè)計(jì)沖孔模時(shí),以凸模尺寸為基準(zhǔn),間隙取在凹模上。 (2)考慮到?jīng)_裁中凸、凹模的磨損,設(shè)計(jì)落料凹模時(shí),凹?;境叽鐟?yīng)取尺寸公差范圍的較小尺寸;設(shè)計(jì)沖孔模時(shí),凹模基本尺寸應(yīng)取工件孔尺寸公差范圍的較大尺寸。這樣在凸凹麼磨損到一定程度的情況下,仍能沖出合格的制件。凸凹模間隙則取最小合理間隙值。 (3)確定沖模刃口制造公差時(shí),應(yīng)考慮制件的公差要求。如果對(duì)刃口精度要求過高(即制造公差過?。?,會(huì)使模具制造困難,增加成本,延長(zhǎng)生產(chǎn)周期;如果對(duì)刃口要求過低(即制造公差過大)則生產(chǎn)出來的制件可能不合格,會(huì)使模具的壽命降低。若制件沒有標(biāo)注公差,則對(duì)于非圓形工件按國(guó)家標(biāo)準(zhǔn)“非配合尺寸的公差數(shù)值”IT14級(jí)處理,沖模則可按IT11級(jí)制造;對(duì)于圓形件,一般可按IT7IT6級(jí)制造模具。沖壓件的尺寸公差應(yīng)按“入體”原則標(biāo)注,落料件上偏差為零,下偏差為負(fù);沖孔件下偏差為零,上偏差為正。6.2刃口尺寸計(jì)算該零件的材料是20鋼,厚度是1.5mm,該零件是屬于無特殊要求,屬于一般沖裁件,經(jīng)過查表2.2.4可知2Cmax =0.095 2Cmin =0.065 所以2Cmax-2Cmin =0.095-0.065=0.03 零件的外形尺寸由落料獲得 ,而孔11由沖孔獲得。由公差表查得11, IT=9,x=0.75 , x=0.5 設(shè)計(jì)凸凹模分別按IT6, IT7級(jí)別加工制造則: 0.011+0.018 0.095-0.065=0.030.029 0.03 由此可知只有縮小值,提高制造精度才能保證間隙在合理間隙內(nèi)。因此?。?以凹模尺寸為基準(zhǔn),凸模、凹模分別以IT6、IT7級(jí)加工 。凸模: 凹模: 0.03只有縮小值提高制造精度才能保證間隙在合理間隙內(nèi)。因此?。?孔中心距尺寸: 6.3凹模的外形輪廓尺寸沖裁凹模外形輪廓尺寸主要根據(jù)被加工板料的厚度和沖裁件的最大外形尺寸確定,并綜合考慮與其他零件的連接因素。凹模的外形尺寸主要指凹模的厚度(或稱高度)H及壁厚(c)。 凹模厚度: (H15mm); 凹模壁厚:c=(1.52)H c(3040)式中:b沖裁件的最大外形尺寸; K系數(shù)(板料厚度影響)。經(jīng)過查表2.8.1可知: K取0.35 所以凹模厚度: 根據(jù)考慮強(qiáng)度,H取20 凹模壁厚:,取C=35mm 所以凹模寬度B和長(zhǎng)度A分別為: 凹模寬度:B=2C+30=235+30=100 凹模長(zhǎng)度A=2C+54=235+54=124 所以B取117 mm A=142mm根據(jù)裝配、銷位置以及螺釘排放要求,這里凹模寬度取117mm,為配合合適的模架,實(shí)取L=142 mm故確定凹模的外形尺寸為:14211720。如圖1-3所示: 圖1-3 落料凹模 6.4凸模設(shè)計(jì)計(jì)算因?yàn)樵谌锌谟?jì)算是得到是24及11孔的尺寸分別為:6孔:凹模直徑: 凸模直徑: 經(jīng)過查沖壓模具簡(jiǎn)明設(shè)計(jì)手冊(cè)表2.5.4可知 取得到凸模的相關(guān)數(shù)據(jù): 直徑:d=6.09mm,基本尺寸: , ,, l=3655mm 凸模的長(zhǎng)度: h1 凸模固定板厚度 h2襯板厚度 h3 凹模厚度 l附加長(zhǎng)度,一般取1530mm (包括凸模進(jìn)入凹模深度,凸模的修模量及凸模固定板與卸料板之間的安全高度) 11孔: 凸模直徑: 凹模直徑: 經(jīng)過查沖壓模具簡(jiǎn)明設(shè)計(jì)手冊(cè)表2.54可知取得到凸模的相關(guān)數(shù)據(jù):直徑:d=11.09mm,基本尺寸:D=16mm, D1=19mm,h=3mm, l=4290mm凸模長(zhǎng)度:h1 凸模固定板厚度;h2襯板厚度;h3 凹模厚度;l附加長(zhǎng)度 一般取1530mm(包括凸模進(jìn)入凹模深度,凸模的修模量及凸模固定板與卸料板之間的安全高度) 6.5 凸凹模計(jì)算高度計(jì)算:h=h1+h2+h3 =25+30+15 =70mm h1 凸凹模固定板厚度;h2橡皮厚度;h3 推料板厚度。如圖1-5所示: 圖1-5 凸凹模7 模具結(jié)構(gòu)設(shè)計(jì)根據(jù)上述工藝分析,該模具可以保證零件所要求的各項(xiàng)精度指標(biāo),工序次數(shù)少,生產(chǎn)效率高,適用于大批量生產(chǎn)。若采用自動(dòng)送料,操作就更為安全。其特點(diǎn)如下: (1)該模具采用滑動(dòng)式導(dǎo)柱導(dǎo)套的后側(cè)式標(biāo)準(zhǔn)模架,根據(jù)刃口尺寸大小確定凹模的周界大小為160140mm、閉合高度Hmax-5hHmin+10,H為壓力機(jī)的最大、小閉合高度,所以h=215185mm,這里取210mm。 (2)為保證制件的平直度及沖壓工作的操作安全,設(shè)計(jì)倒裝式復(fù)合模結(jié)構(gòu) ,落料凹模安裝于上模,凸凹模安裝于下模,它們分別依靠銷釘或接觸面定位,與導(dǎo)柱和導(dǎo)套的相對(duì)位置比較精確,從需實(shí)現(xiàn)導(dǎo)柱導(dǎo)向的目標(biāo)。 (3)該制件材料厚度適中,適合采用手動(dòng)送料,條料送進(jìn)導(dǎo)向精度由導(dǎo)料銷保證。條料送進(jìn)定距則設(shè)計(jì)了最簡(jiǎn)單的擋料銷裝置,為避免擋料銷安裝孔距離凹凸模太近,擋料銷選用標(biāo)準(zhǔn)的結(jié)構(gòu)形式。 (4)退料機(jī)構(gòu)分別為上模剛性推件裝置和下模彈性卸料裝置 ,剛性推件裝置結(jié)構(gòu)簡(jiǎn)單,加工成本低,但是需要依靠壓力機(jī)上的打料橫梁進(jìn)行工作,所以設(shè)計(jì) 時(shí)務(wù)必考慮打料橫梁的位置及調(diào)節(jié)量。彈性卸料裝置采用的是橡膠作為彈性元件,卸料板通過卸料螺釘與下模相對(duì)固定,為保證卸料板的平整,下模座上加工通孔,卸料螺釘掛頭接角面為墊板下表面,這樣避免了下模座孔卸料螺釘沉孔深度難以保證的缺陷,從需降低加工難度。 (5)模具工作過程:條料沿導(dǎo)料銷送進(jìn)抵住活動(dòng)擋料銷;上模下行,首先是條料由下模的彈性卸料裝置(彈性元件為橡膠)與凹模夾緊;上模繼續(xù)下行,凸凹模、沖孔凸模和凹模同時(shí)工作將條料沖斷后,上模到達(dá)下止點(diǎn);沖孔廢料被卡在凸凹模的沖孔凹模型孔中,待下一次沖裁周期將其推出從下模漏料孔中漏出;落料廢料箍在凸凹模的落料刃口上,上?;爻虝r(shí)橡膠回彈推動(dòng)卸料板將其撥落下來;制件則卡在凹模的型孔中,上?;爻虝r(shí),打桿在上模沒有到達(dá)上止點(diǎn)時(shí)即碰到壓力機(jī)上的打料橫梁而停止運(yùn)動(dòng),推動(dòng)推板將制件推出,落在下模表面。移走制件后,再將條料抵住活動(dòng)擋料銷,開始第二次沖裁,周而復(fù)始。8 沖壓模模具結(jié)構(gòu)件選取模架:模架包括上模座板、下模座板、導(dǎo)柱和導(dǎo)套。沖壓模具的全部零件都安裝在模架上。根據(jù)模架導(dǎo)向的導(dǎo)柱配合性質(zhì)分為:滑動(dòng)導(dǎo)向模架和滾動(dòng)導(dǎo)向模架。每一類模架中,由于導(dǎo)柱安裝位置和數(shù)量不同,又分為幾類標(biāo)準(zhǔn)模架,分別為:后側(cè)導(dǎo)柱式,中間導(dǎo)柱式,對(duì)角導(dǎo)柱式,四角導(dǎo)柱式。見沖壓模具簡(jiǎn)明設(shè)計(jì)手冊(cè)表15.1中的標(biāo)準(zhǔn)模架類型根據(jù)兩件的凹模的外形尺寸,和模具閉合高度,選取后側(cè)導(dǎo)柱式模架。 凹模的外形尺寸為142117 閉合高度為H=210,經(jīng)查沖壓模具簡(jiǎn)明設(shè)計(jì)手 冊(cè)表15.2表15.4,還有表15.10、表15.11可知。所以選取:凹模周界:LB=160125。后側(cè)導(dǎo)柱式的上模座板的凹模周界基本尺寸為:LBH =16012540 ,和導(dǎo)套配合的孔的直徑為D=38,兩孔距為S=210mm,上模座板的外形尺寸為A2=85,L1=210,圓角為R=38,l2=80mm.下模座板的基本尺寸為:LBH =16012540 和導(dǎo)套配合的孔的直徑為D=25,兩孔距為S=210mm,上模座板的外形尺寸為A2=85,L1=210,圓角為R=38,l2=80mm.導(dǎo)套經(jīng)查表15.24可知,其基本尺寸為:d=25,D=38,總長(zhǎng)度L=90mm,H=28mm.導(dǎo)柱:經(jīng)查表15.24可知,導(dǎo)柱的基本尺寸:d=25,總長(zhǎng)度L=150mm,導(dǎo)料銷:根據(jù)模具結(jié)構(gòu)特點(diǎn)和和條料上沖壓件排樣的特點(diǎn),選用了合適的導(dǎo)料。9 模具零件制造工藝9.1 模具零件的加工通零件的加工是按產(chǎn)品零件圖要求全部加工完畢,再進(jìn)行總裝。而模具零件的加工有些是不能按模具零件圖全部加工完畢的,要待部件組裝或整模組裝時(shí)修配或配鉆,所以模具零件圖上的形狀和尺寸是否全部加工出來,還要根據(jù)模具加工的裝配方法而定。若以凸模凹模為基準(zhǔn)裝配時(shí),零件圖上的導(dǎo)柱孔在零件加工時(shí)就不加工,若以四導(dǎo)柱導(dǎo)套作型腔,凸模相對(duì)位置控制基準(zhǔn)時(shí),則凹模及凸模固定板的導(dǎo)柱孔應(yīng)與凹?;蛲鼓9潭ò宓男涂自诟靼逯贤瑫r(shí)加工出來。 使用銑床加工一個(gè)零件時(shí),必須先把零件的相關(guān)尺寸、材料、使用刀具、加工參數(shù)確定下來,保證加工能順利完成,同時(shí),設(shè)計(jì)方面也要考慮到加工的難易程度,以減少加工的困難,在加工模具零件之前要慎重考慮各種細(xì)節(jié)。在買回來的模板里,要確定模板的加工基準(zhǔn),哪些面是基準(zhǔn)面,這一般在訂購(gòu)模板時(shí)會(huì)標(biāo)明哪幾個(gè)面是經(jīng)過打磨,之后就是把加工基準(zhǔn)定下來,當(dāng)然事前必須準(zhǔn)備好零件圖,根據(jù)零件圖來定位加工方案,如果要用到數(shù)控編程,就必須把加工原點(diǎn)定出來。定好加工方案后,就可以開始加工,先把工件裝夾到虎口鉗上,使用銅錘敲擊以使工件被夾緊,然后打表,在打表時(shí)要非常小心,當(dāng)表很靠近工件時(shí),不能使用加速進(jìn)給,否則很容易碰壞儀器,在校平行度時(shí),最好先來回走幾遍,觀察大概偏向,然后要小心敲擊工件,使其保持在很小的偏差范圍就行了,把兩個(gè)基準(zhǔn)方向的平行度定好后,就要用分中器確定原點(diǎn)坐標(biāo),在設(shè)置坐標(biāo)時(shí)要將分中器的半徑算進(jìn)去,這樣才能使主軸對(duì)應(yīng)工件原點(diǎn),x-y平面的坐標(biāo)定下來后,就要把刀具裝到銑床上,使用半徑范圍內(nèi)的夾具把刀具夾緊,裝上道具后就是確定z方向上的原點(diǎn),一般選擇工件表面為0以方便編程。之后就是加工,如果是選用數(shù)控加工,必須使程序和當(dāng)前銑床的刀具起點(diǎn)相一致,否則加工位置就會(huì)錯(cuò)誤,同時(shí)還要察看刀具路線是否會(huì)超出銑床的工作行程,防止出事故。如果程序沒錯(cuò),就可以傳到數(shù)控銑床運(yùn)行。不同刀具要使用不同轉(zhuǎn)速,鉆孔要比銑槽的轉(zhuǎn)速慢,進(jìn)給速度要根據(jù)觀察來手動(dòng)調(diào)試,加工時(shí)要時(shí)刻觀察走刀情況,同時(shí)適當(dāng)加冷卻液及掃除鐵屑,若發(fā)生事故,必須馬上停止。當(dāng)程序完成后,刀具就會(huì)回原點(diǎn),繼續(xù)做下一工序。9.2沖壓工藝規(guī)程凹模加工工藝過程 材料:T10A 硬度:6064HRC序號(hào)工序號(hào)工序內(nèi)容1備料鍛件(退火狀態(tài)):170150302粗銑銑六面到尺寸15513025注意兩大平面與相鄰鄰側(cè)面用標(biāo)準(zhǔn)角尺測(cè)量達(dá)基本垂直3平面磨磨光兩大平面厚度達(dá)25,并磨兩相鄰側(cè)面達(dá)四面垂直。垂直度0.02/1004鉗劃線 劃出各孔徑中心線并劃出凹模洞口輪廓尺寸鉆孔 鉆螺紋底孔,銷釘?shù)卓?,凹模洞口穿線孔鉸孔 鉸銷釘孔到要求攻絲 攻螺紋絲到要求5熱處理淬火使硬度達(dá)6064HRC6平面磨磨光兩大平面,使厚度達(dá)257線切割割凹模洞口,并留0.010.02研余量8鉗研磨洞口內(nèi)壁側(cè)面達(dá)0.8um 配推件塊到要求9鉗用墊片層保證凸凹模與凹模間隙均勻后,凹模與上模座配作銷釘孔10平磨磨凹模板上平面厚度達(dá)要求11鉗總裝配凸模加工工藝過程 材料:T1OA 硬度:5660HRC 序號(hào)工序名稱工序內(nèi)容1備料鍛件(退火狀態(tài)):20702熱處理退火,硬度達(dá)180220HB3車 一端面,打頂尖孔。車外圓至16.5;掉頭車另一端面,長(zhǎng)度至尺寸65;打孔尖孔。雙頂尖頂,車外圓尺寸12.24檢驗(yàn)檢驗(yàn)5熱處理淬火,硬度至5660H RC。6磨削磨削外圓尺寸12至要求7線切削切除工作端面頂尖孔,長(zhǎng)度尺寸至要求8磨削磨削端面至Ra0.8um9檢驗(yàn)10鉗工裝配(鉗修并裝配,保證)凹凸模加工工藝過程 材料:T10A 硬度:6064HRC序號(hào)工序名稱工序內(nèi)容1備料鍛件(退火狀態(tài)):6540702粗銑銑各面見光3平磨磨高度兩平面到尺寸70.44鉗 劃線 在長(zhǎng)度方一側(cè)線切割?yuàn)A位6后,分中劃凸模輪廓線并劃兩凹模洞口中線 鉆孔 按凹模洞口中心鉆線切割穿絲孔锪擴(kuò)凹模落料沉孔到要求,鉆螺紋底孔并攻絲到要求5熱處理淬火 硬度達(dá)6064HRC6平磨磨高度到707線切割割凸模及兩凹模,并單邊留0.010.02研磨余量8鉗 研配 研凸凹模并配入凸模固定板 研磨各側(cè)壁到0.8um9平磨磨高度到要求10鉗總裝配凸模固定板加工工藝過程 材料:45 硬度:2428HRC序號(hào)工序名稱工序內(nèi)容1備料氣割下料170130252熱處理調(diào)質(zhì) 硬度2428HRC3粗銑銑六面達(dá)15512121mm,并使兩大平面和相鄰兩側(cè)面相互基本垂直4平磨磨光兩大平面厚度達(dá)17,并磨兩相鄰側(cè)面使四面垂直,垂直度0.02/1005鉗劃線 凸模固定孔中心線,銷釘孔中心線,螺紋過中心線,銷釘過孔中心線鉆孔 凸模固定孔穿絲線,螺紋過孔和銷釘過孔到要求6線切割割凸模安裝固定孔單邊留0.010.02研余量7銑銑凸模固定孔背面沉孔到要求8鉗研配凸模9平磨磨模厚度到要求10鉗總裝配 用透光層使凸模,凹模間隙均勻后,與上模座板配作銷孔凸凹模固定板加工工藝過程 材料:45 硬度:2428HRC序號(hào)工序名稱工序內(nèi)容1備料氣割下料170130352熱處理調(diào)質(zhì) 硬度2428HRC 3粗銑銑六面達(dá)16512330,并使兩大平面和相鄰兩側(cè)面基本垂直4平磨磨光兩大平面,厚度達(dá)25,并磨兩相鄰側(cè)面使 四面垂直,垂直度0.02/1005鉗劃線 螺紋孔中心線,螺紋過孔中心線,銷釘孔中心線,凸凹模固定孔輪廓線鉆孔螺紋底孔,螺紋過孔到要求,凸凹模固定孔線切割穿線孔攻絲 攻螺紋底絲到要求6線切割割凸凹模安裝固定孔,單邊留研余量0.010.027鉗研配 將凸凹模配入安裝固定孔8平磨磨厚度到要求9鉗裝配 與下模座配作銷釘孔10 模具的裝配根據(jù)簡(jiǎn)單模的工作特點(diǎn),先裝上模,再裝下模較為合理,并調(diào)整間隙、試沖、返修、具體過程如下:(1)上模裝配 仔細(xì)檢查各將要裝配零件是否符合圖紙要求,形狀并作好劃線,定位等準(zhǔn)備工作; 先將凸模與凸模固定板裝配,再與凹模板裝配,并調(diào)整間隙; 把已裝配好的凸模及凹模與上模座,并在次檢查間隙是否合理后,打入銷釘及擰入螺絲。(2)下模裝配 仔細(xì)檢查各將要裝配零件是否符合圖紙要求,形狀并作好劃線,定位等準(zhǔn)備工作。 先將凸凹模放在下模座上,再裝入凸凹模固定板并調(diào)整間隙,以免發(fā)生干涉及工件損壞。接著依次按順序裝入銷釘,活動(dòng)擋料銷,彈頂橡膠塊及卸料板,檢查間隙等合理后擰入卸料螺釘,再擰入緊固螺釘,并再次檢查調(diào)整。 將經(jīng)調(diào)整后的上下模按導(dǎo)柱,導(dǎo)套配合進(jìn)行組裝,檢查間隙及其它裝配合理后裝機(jī)進(jìn)行試沖并根據(jù)試沖結(jié)果作出相應(yīng)調(diào)整,直到生產(chǎn)出合格制件。 刷片正裝復(fù)合模具裝配圖如圖總 結(jié) 學(xué)校為了培養(yǎng)大批具有必備的理論知識(shí)和較強(qiáng)的實(shí)踐能力,適應(yīng)生產(chǎn)、建設(shè)、管理、服務(wù)第一線急需的高等技術(shù)應(yīng)用性專門人才。試圖通過沖壓工藝與模具設(shè)計(jì)讓學(xué)生初步掌握模具工藝設(shè)計(jì)和模具結(jié)構(gòu)設(shè)計(jì)的方法和步驟。把已學(xué)的各門專業(yè)課程基礎(chǔ)理論綜合的應(yīng)用在模具的計(jì)算過程中去。培養(yǎng)學(xué)生分析問題、解決問題的能力、實(shí)踐動(dòng)手能力。本人通過對(duì)本套沖裁件的沖孔簡(jiǎn)單模的設(shè)計(jì)、計(jì)算,使我對(duì)沖裁模的設(shè)計(jì)流程有了更深一層的了解,包括沖裁件的工藝分析、工藝方案的確定、模具結(jié)構(gòu)形式的選擇、必要的工藝計(jì)算、主要零部件的設(shè)計(jì)、壓力機(jī)型號(hào)的選擇、總裝圖及零件圖的繪制。在設(shè)計(jì)過程中,有些數(shù)據(jù)、尺寸是一點(diǎn)也馬虎不得,只要一個(gè)數(shù)據(jù)有誤,就得全部改動(dòng),使設(shè)計(jì)難度大大的增加。在這次設(shè)計(jì)中,我感覺要完成這次設(shè)計(jì)不僅要有扎實(shí)的專業(yè)知識(shí),還要有過硬的計(jì)算機(jī)基礎(chǔ)作保障,方能很好的完成這次設(shè)計(jì)。所以說我們今后的學(xué)習(xí)中不僅要學(xué)好應(yīng)該所學(xué)的,還要盡可能多的去拓展在其它方面的領(lǐng)域,只有這們我們才能立于不敗之地。 致謝京過本次課程設(shè)計(jì),本人學(xué)到了很多知識(shí)。在此,首先非常感謝所有傳授知識(shí)予我的老師們,其次要感謝我的指導(dǎo)老師,感謝他提供的耐心指導(dǎo)以及各種幫助。同時(shí),也要感謝陪伴我一同做實(shí)訓(xùn)的銅學(xué)們,感謝他們給予的鼓勵(lì)與幫助,感謝他們?nèi)杖找挂沟呐惆?。在這次課程設(shè)計(jì)過程中,有了老師和同學(xué)們的幫助,才使得我順利完成這次課程設(shè)計(jì)并從中學(xué)到了更為廣泛的知識(shí)和實(shí)際操作能力以及為人處事能力。同時(shí),還要感謝在本文中引用其文獻(xiàn)的作者們,是他們奉獻(xiàn)的辛勤勞動(dòng)成果才使得我在這次課程設(shè)計(jì)學(xué)習(xí)當(dāng)中有了清晰的思路,才使自己在遇到的困難時(shí)能很快得以解決,順順利利的完成了這次設(shè)計(jì)。最后,再次衷心地感謝給予我?guī)椭睦蠋熞约芭惆樵谖疑磉叺拿恳晃煌瑢W(xué),是他們一直陪伴著我學(xué)習(xí)、生活,當(dāng)我有困難的時(shí)候,他們也是非常樂意奉獻(xiàn)出各種力所能及的力量來為我排憂解難。感謝他們對(duì)我的學(xué)習(xí)和生活的照顧。參考文獻(xiàn)【1】 原紅玲.沖壓工藝與模具設(shè)計(jì) 普通高等??平逃龣C(jī)電類規(guī)劃教材.【2】 鐘毓斌.沖壓工藝與模具設(shè)計(jì)第2版【3】 馬霄,任泰安.互換性與測(cè)量技術(shù)基礎(chǔ)M.北京理工大學(xué)出版社,2007【4】 楊占堯.沖壓模具圖冊(cè)M.北京:高等教育出版社,2004.7【5】王孝培.沖壓手冊(cè)M .北京;機(jī)械工業(yè)出版社1990.- 25 -沖壓成形與板材沖壓 1 概述通過模具使板材產(chǎn)生塑性變形而獲得成品零件的一次成形工藝方法叫做沖壓。由于沖壓通常在冷態(tài)下進(jìn)行,因此也稱為冷沖壓。只有當(dāng)板材厚度超過8100mm時(shí),才采用熱沖壓。沖壓加工的原材料一般為板材或帶材,故也稱板材沖壓。某些非金屬板材(如膠木板、云母片、石棉、皮革等)亦可采用沖壓成形工藝進(jìn)行加工。沖壓廣泛應(yīng)用于金屬制品各行業(yè)中,尤其在汽車、儀表、軍工、家用電器等工業(yè)中占有極其重要的地位。沖壓成形需研究工藝設(shè)備和模具三類基本問題。 板材沖壓具有下列特點(diǎn): (1)高的材料利用率。(2)可加工薄壁、形狀復(fù)雜的零件。(3)沖壓件在形狀和尺寸方面的互換性好。(4)能獲得質(zhì)量輕而強(qiáng)度高、剛性好的零件。(5)生產(chǎn)率高,操作簡(jiǎn)單,容易實(shí)現(xiàn)機(jī)械化和自動(dòng)化。沖壓模具制作成本高,因此適合大批量生產(chǎn)。對(duì)于小批量、多品種生產(chǎn),常采用簡(jiǎn)易沖模,同時(shí)引進(jìn)沖壓加工中心等新型設(shè)備,以滿足市場(chǎng)求新求變的需求。板材沖壓常用的金屬材料有低碳鋼、銅、鋁、鎂合金及高塑性的合金剛等。如前所述,材料形狀有板材和帶材。沖壓生產(chǎn)設(shè)備有剪床和沖床。剪床是用來將板材剪切成具有一定寬度的條料,以供后續(xù)沖壓工序使用,沖床可用于剪切及成形。 2 沖壓成形的特點(diǎn)生產(chǎn)時(shí)間中所采用的沖壓成形工藝方法有很多,具有多種形式餓名稱,但塑性變形本質(zhì)是相同的。沖壓成形具有如下幾個(gè)非常突出的特點(diǎn)。 (1)垂直于板面方向的單位面積上的壓力,其數(shù)值不大便足以在板面方向上使板材產(chǎn)生塑性變形。由于垂直于板面方向上的單位面積上壓力的素質(zhì)遠(yuǎn)小于板面方向上的內(nèi)應(yīng)力,所以大多數(shù)的沖壓變形都可以近似地當(dāng)作平面應(yīng)力狀態(tài)來處理,使其變形力學(xué)的分析和工藝參數(shù)的計(jì)算大呢感工作都得到很大的簡(jiǎn)化。 (2)由于沖壓成形用的板材毛胚的相對(duì)厚度很小,在壓應(yīng)力作用下的抗失穩(wěn)能力也很差,所以在沒有抗失穩(wěn)裝置(如壓邊圈等)的條件下,很難在自由狀態(tài)下順利地完成沖壓成形過程。因此,以拉應(yīng)力作用為主的伸長(zhǎng)類沖壓成形過程多于以壓應(yīng)力作用為主的壓縮類成形過程。 (3)沖壓成形時(shí),板材毛胚內(nèi)應(yīng)力的數(shù)值等于或小于材料的屈服應(yīng)力。在這一點(diǎn)上,沖壓成形與體積成形的差別很大。因此,在沖壓成形時(shí)變形區(qū)應(yīng)力狀態(tài)中的靜水壓力成分對(duì)成形極限與變形抗力的影響,已失去其在體積成形時(shí)的重要程度,有些情況下,甚至可以完全不予考慮,即使有必要考慮時(shí),其處理方法也不相同。 (4)在沖壓成形時(shí),模具對(duì)板材毛胚作用力所形成的約束作用較輕,不像體積成形(如模鍛)是靠與制件形狀完全相同的型腔對(duì)毛胚進(jìn)行全面接觸而實(shí)現(xiàn)的強(qiáng)制成形。在沖壓成形中,大多數(shù)情況下,板材毛胚都有某種程度的自由度,常常是只有一個(gè)表面與模具接觸,甚至有時(shí)存在板材兩側(cè)表面都有于模具接觸的變形部分。在這種情況下,這部分毛胚的變形是靠模具對(duì)其相鄰部分施加的外力實(shí)現(xiàn)其控制作用的。例如,球面和錐面零件成形時(shí)的懸空部分和管胚端部的卷邊成形都屬這種情況。 由于沖壓成形具有上述一些在變形與力學(xué)方面的特點(diǎn),致使沖壓技術(shù)也形成了一些與體積成形不同的特點(diǎn)。由于不需要在板材毛的表面施加很大的單位壓力即可使其成形,所以在沖壓技術(shù)中關(guān)于模具強(qiáng)度與剛度的研究并不十分重要,相反卻發(fā)展了學(xué)多簡(jiǎn)易模具技術(shù)。由于相同原因,也促使靠氣體或液體壓力成形的工藝方法得以發(fā)展。因沖壓成形時(shí)的平面應(yīng)力狀態(tài)或更為單純的應(yīng)變狀態(tài)(與體積成形相比),當(dāng)前對(duì)沖壓成形匯中毛胚的變形與 力能參數(shù)方面的研究較為深入,有條件運(yùn)用合理的科學(xué)方法進(jìn)行沖壓加工。借助于電子計(jì)算機(jī)與先進(jìn)的測(cè)試手段,在對(duì)板材性能與沖壓變形參數(shù)進(jìn)行實(shí)時(shí)測(cè)量與分析基礎(chǔ)上,實(shí)現(xiàn)沖壓過程智能化控制的研究工作也在開展。人們?cè)趯?duì)沖壓成形過程有離開較為深入的了解后,已經(jīng)認(rèn)識(shí)到?jīng)_壓成型與原材料有十分密切的關(guān)系。所以,對(duì)板材沖壓性能即成形性與形狀穩(wěn)定性的研究,目前已成為沖壓技術(shù)的一個(gè)重要內(nèi)容。對(duì)板材沖壓性能的研究工作不僅是沖壓技術(shù)發(fā)展的需要,而且也促進(jìn)了鋼鐵工業(yè)生產(chǎn)技術(shù)的發(fā)展,為其提高板材的質(zhì)量提供了一個(gè)可靠的基礎(chǔ)與依據(jù)。 3沖壓變形的分類 沖壓變形工藝可完成多種工序,其基本工序可分為分離工序和變形工序兩大類。分離工序是使胚料的一部分與另一部分相互分離的工藝方法,主要有落料、沖孔、切邊、剖切、修整等。其中又以沖孔、落料應(yīng)用最廣。變形工序是使胚料的一部分相對(duì)于另一部分產(chǎn)生位移而不破裂的工藝方法,主要有拉深、彎曲、局部成形、脹形、翻邊、縮徑、校形、旋壓等。從本質(zhì)上看,沖壓成形就是毛胚的變形區(qū)在外力的作用下產(chǎn)生相應(yīng)的塑性變形,所以變形區(qū)內(nèi)的應(yīng)力狀態(tài)和變形特點(diǎn)景象的沖壓成形分類,可以把成形性質(zhì)相同的成形方法概括成同一個(gè)類型并進(jìn)行體系化的研究。絕大多數(shù)沖壓成形時(shí)毛胚變形區(qū)均處于平面應(yīng)力狀態(tài)。通常認(rèn)為在板材表面上不受外力的作用,即使有外力作用,其數(shù)值也是較小的,所以可以認(rèn)為垂直于板面方向上的應(yīng)力為零,使板材毛胚產(chǎn)生塑性變形的是作用于板面方向上相互的兩個(gè)主應(yīng)力。由于板厚較小,通常都近似地認(rèn)為這兩個(gè)主應(yīng)力在厚度方向上是均勻分布的?;谶@樣的分析,可以把各種形式?jīng)_壓成型中的毛陪變形區(qū)的受力狀態(tài)與變形特點(diǎn),在平面應(yīng)力的應(yīng)力坐標(biāo)系中與相應(yīng)的兩向應(yīng)變坐標(biāo)系中以應(yīng)力與應(yīng)變坐標(biāo)決定的位置來表示。4.沖壓用原材料 沖壓加工用原材料有很多種,它們的性能也有很大的差別,所以必須根據(jù)原材料的性能與特點(diǎn),采用不同的沖壓成形方法、工藝參數(shù)和模具結(jié)構(gòu),才能達(dá)到?jīng)_壓加工的目的。由于人們對(duì)沖壓成形過程板材毛胚的變形行為有了較為深入的認(rèn)識(shí),已經(jīng)相當(dāng)清楚的建立了由原材料的化學(xué)成分、組織等因素所決定的材料性能與沖壓成形之間的關(guān)系,這就使原材料生產(chǎn)部門不但按照沖壓件的工作條件與使用要求進(jìn)行原材料的設(shè)計(jì)工作,而且也根據(jù)沖壓件加工過程對(duì)板材性能的要求進(jìn)行新型材料的開發(fā)工作,這是沖壓技術(shù)在原材料研究方面的一個(gè)重要方向。對(duì)沖壓用原材料沖壓性能方面的研究工作有(1)原材料沖壓性能的含義。(2)判斷原材料沖壓性能的科學(xué)方法,確定可以確切反映材料沖壓性能的參數(shù),建立沖壓性能的參數(shù)與實(shí)際沖壓成形間的關(guān)系,以及沖壓性能參數(shù)的測(cè)試方法等。 (3)建立原材料的化學(xué)成分、組織和制造過程與沖壓性能之間的關(guān)系。沖壓用原材料主要是各種金屬與非金屬板材。金屬板材包括各種黑色技術(shù)和有色金屬板材。雖然在沖壓生產(chǎn)中所用金屬板材的種類很多,但最多的原材料蛀牙是鋼板、不銹鋼板、鋁合金板及各種復(fù)合金屬板。5板材沖壓性能及其鑒定方法 板材是指對(duì)沖壓加工的適應(yīng)能力。對(duì)板材沖壓性能的研究具有飛行重要的意義。為了能夠運(yùn)用最科學(xué)與最經(jīng)濟(jì)合理的沖壓工藝過程與工藝參數(shù)制造出沖壓零件,必須對(duì)作為加工對(duì)象的板材的性能具有十分清楚的了解,這樣才有可能充分地利用板材在加工方面的潛在能力。另一方面,為了能夠依據(jù)沖壓件的形狀與尺寸特點(diǎn)及其所需的成形工藝等基本因素,正確、合理地選用板材,也必須對(duì)板材的沖壓性能有一個(gè)科學(xué)的認(rèn)識(shí)與正確的判斷。評(píng)定板材沖壓性能的方法有直接試驗(yàn)法與間接試驗(yàn)法。 實(shí)物沖壓試驗(yàn)是最直接的板材沖壓性能的評(píng)定方法。利用實(shí)際生產(chǎn)設(shè)備與模具,在與生產(chǎn)完全相同的條件下進(jìn)行實(shí)際沖壓零件的性能評(píng)定,當(dāng)然能夠的最可靠的結(jié)果。但是,這種評(píng)定方法不具有普遍意義,不能作為行業(yè)之間的通用標(biāo)準(zhǔn)進(jìn)行信息的交流。 模擬試驗(yàn)是把生產(chǎn)中實(shí)際存在的沖壓成形方法進(jìn)行歸納與簡(jiǎn)單化處理,消除許多過于復(fù)雜的因素,利用軸對(duì)稱的簡(jiǎn)化了的成形方法,在保證試驗(yàn)中板材的變形性質(zhì)與應(yīng)力狀態(tài)都與實(shí)際沖壓成形相同的條件下進(jìn)行的沖壓性能的評(píng)定工作。為了保證模擬試驗(yàn)結(jié)果的可靠性與通用性,規(guī)定了私分具體的關(guān)于試驗(yàn)用工具的幾何形狀與尺寸、毛胚的尺寸、試驗(yàn)條件(沖壓速度、潤(rùn)滑方法、壓邊力等)。 間接試驗(yàn)法也叫做基礎(chǔ)試驗(yàn)法。間接試驗(yàn)法的特點(diǎn)是:在對(duì)板材在塑性變形過程中所表現(xiàn)出的基本性質(zhì)與規(guī)律進(jìn)行分析與研究的基礎(chǔ)上,進(jìn)一步把它和具體的沖壓成形中板材的塑性變形參數(shù)聯(lián)系起來,建立間接試驗(yàn)結(jié)果(間接試驗(yàn)值)與具體的沖壓成形性能(工藝參數(shù))之間的相關(guān)性。由于間接試驗(yàn)時(shí)所用試件的形狀與尺寸以及加載的方式等都不同于具體的沖壓成形過程,所以它的變形性質(zhì)和應(yīng)力狀態(tài)也不同于沖壓變形。因此間接試驗(yàn)所得的結(jié)果(試驗(yàn)值)并不是沖壓成形的工藝參數(shù),而是可以用來表示板材沖壓性能的基礎(chǔ)性參數(shù)。Characteristics and Sheet Metal Forming1 The article overview Stamping is a kind of plastic forming process in which a part is produced by means of the plastic forming the material under the action of a die. Stamping is usually carried out under cold state, so it is also called stamping. Heat stamping is used only when the blank thickness is greater than 8100mm. The blank material for stamping is usually in the form of sheet or strip, and therefore it is also called sheet metal forming. Some non-metal sheets (such as plywood, mica sheet, asbestos, leather)can also be formed by stamping. Stamping is widely used in various fields of the metalworking industry, and it plays a crucial role in the industries for manufacturing automobiles, instruments, military parts and household electrical appliances, etc. The process, equipment and die are the three foundational problems that needed to be studied in stamping. The characteristics of the sheet metal forming are as follows: (1) High material utilization (2) Capacity to produce thin-walled parts of complex shape. (3) Good interchangeability between stamping parts due to precision in shapeand dimension. (4) Parts with lightweight, high-strength and fine rigidity can be obtained. (5) High productivity, easy to operate and to realize mechanization and automatization. The manufacture of the stamping die is costly, and therefore it only fits to mass production. For the manufacture of products in small batch and rich variety, the simple stamping die and the new equipment such as a stamping machining center, are usually adopted to meet the market demands. The materials for sheet metal stamping include mild steel, copper, aluminum, magnesium alloy and high-plasticity alloy-steel, etc.Stamping equipment includes plate shear punching press. The former shears plate into strips with a definite width, which would be pressed later. The later can be used both in shearing and forming. 2Characteristics of stamping forming There are various processes of stamping forming with different working patterns and names. But these processes are similar to each other in plastic deformation. There are following conspicuous characteristics in stamping: (1)The force per unit area perpendicular to the blank surface is not large but is enough to cause the material plastic deformation. It is much less than the inner stresses on the plate plane directions. In most cases stamping forming can be treated approximately as that of the plane stress state to simplify vastly the theoretical analysis and the calculation of the process parameters. (2)Due to the small relative thickness, the anti-instability capability of the blank is weak under compressive stress. As a result, the stamping process is difficult to proceed successfully without using the anti-instability device (such as blank holder). Therefore the varieties of the stamping processes dominated by tensile stress are more than dominated by compressive stress. (3)During stamping forming, the inner stress of the blank is equal to or sometimes less than the yield stress of the material. In this point, the stamping is different from the bulk forming. During stamping forming, the influence of the hydrostatic pressure of the stress state in the deformation zone to the forming limit and the deformation resistance is not so important as to the bulk forming. In some circumstances, such influence may be neglected. Even in the case when this influence should be considered, the treating method is also different from that of bulk forming. (4)In stamping forming, the restrain action of the die to the blank is not severs as in the case of the bulk forming (such as die forging). In bulk forming, the constraint forming is proceeded by the die with exactly the same shape of the part. Whereas in stamping, in most cases, the blank has a certain degree of freedom, only one surface of the blank contacts with the die. In some extra cases, such as the forming of the blank on the deforming zone contact with the die. The deformation in these regions are caused and controlled by the die applying an external force to its adjacent area. Due to the characteristics of stamping deformation and mechanics mentioned above, the stamping technique is different form the bulk metal forming: The importance or the strength and rigidity of the die in stamping forming is less than that in bulk forming because the blank can be formed without applying large pressure per unit area on its surface. Instead, the techniques of the simple die and the pneumatic and hydraulic forming are developed. Due to the plane stress or simple strain state in comparison with bulk forming, more research on deformation or force and power parameters has been done. Stamping forming can be performed by more reasonable scientific methods. Based on the real time measurement and analysis on the sheet metal properties and stamping parameters, by means of computer and some modern testing apparatus, research on the intellectualized control of stamping process is also in proceeding. It is shown that there is a close relationship between stamping forming and raw material. The research on the properties of the stamping forming, that is, forming ability and shape stability, has become a key point in stamping technology development, but also enhances the manufacturing technique of iron and steel industry, and provides a reliable foundation for increasing sheet metal quality. 3Categories of stamping forming Many deformation processes can be done by stamping, the basic processes of the stamping can be divided into two kinds: cutting and forming.Cutting is a shearing process that one part of the blank is cut from the other. It mainly includes blanking, punching, trimming, parting and shaving, where punching and blanking are the most widely used. Forming is a process that one part of the blank has some displacement from the other. It mainly includes deep drawing, bending, local forming, bulging, flanging, necking, sizing and spinning. In substance, stamping forming is such that the plastic deformation occurs in the deformation zone of the stamping blank caused by the external force. The stress state and deformation characteristic of the deformation zone are the basic factors to decide the properties of the stamping forming. Based on the stress state and deformation characteristics of the deformation zone, the forming methods can be divided into several categories with the same forming properties and be studied systematically.The deformation zone in almost all types of stamping forming is in the plane stress state. Usually there is no force or only small force applied on the blank surface. When is assumed that the stress perpendicular to the blank surface equals to zero, two principal stresses perpendicular to each other and act on the blank surface produce the plastic deformation of the material. Due to the small thickness of the blank, it is assumed approximately the two principal stresses distribute uniformly along the thickness direction. Based on this analysis, the stress state and the deformation characteristics of the deformation zone in all kinds of stamping forming can be denoted by the points in the coordinates of the plane principal stresses and the coordinates of the corresponding plane principal strains. 4Raw materials for stamping formingThere are a lot of raw materials used in stamping forming, and the properties of these materials may have large difference. The stamping forming can be succeeded only by determining the stamping method, the forming parameters and the die structures according to the properties and characteristics of the raw materials. The deformation of the blank during stamping forming has been investigated quite thoroughly. The relationships between the material properties decided by the chemistry component and structure of the material and the stamping forming has been established clearly. Not only the proper material can be selected based on the working condition and usage demand, but also the new material can be developed according to the demands of the blank properties during processing the stamping part. This is an important domain in stamping forming research. The research on the material properties for stamping forming is as follows: (1)Definition of the stamping property of the material. (2)Method to judge the stamping property of the material, find parameters to express the definitely material property of the stamping forming, establish the relationship between the property parameters and the practical stamping forming, and investigate the testing methods of the property parameters. (3)Establish the relationship among the chemical component, structure, manufacturing process and stamping property. The raw materials for stamping forming mainly include various metals and nonmetal plate. Sheet metal includes both ferrous and nonferrous metals. Although a lot of sheet metals are used in stamping forming, the most widely used materials are steel, stainless steel, aluminum alloy and various composite metal plates. 5Stamping forming property of sheet metal and its assessing methodThe stamping forming property of the sheet metal is the adaptation capability of the sheet metal to stamping forming. It has crucial meaning to the investigation of the stamping forming property of the sheet metal. In order to produce stamping forming parts with most scientific, economic and rational stamping forming process and forming parameters, it is necessary to understand clearly the properties of the sheet metal, so as to utilize the potential of the sheet metal fully in the production. On the other hand, to select plate material accurately and rationally in accordance with the characteristics of the shape and dimension of the stamping forming part and its forming technique is also necessary so that a scientific understanding and accurate judgment to the stamping forming properties of the sheet metal may be achieved. There are direct and indirect testing methods to assess the stamping property of the sheet metal.Practicality stamping test is the most direct method to assess stamping forming property of the sheet metal. This test is done exactly in the same condition as actual production by using the practical equipment and dies. Surely, this test result is most reliable. But this kind of assessing method is not comprehensively applicable, and cannot be shared as a commonly used standard between factories. The simulation test is a kind of assessing method that after simplifying and summing up actual stamping forming methods, as well as eliminating many trivial factors, the stamping properties of the sheet metal are assessed, based on simplified axial-symmetric forming method under the same deformation and stress states between the testing plate and the actual forming states. In order to guarantee the reliability and generality of simulation results, a lot of factors are regulated in detail, such as the shape and dimension of tools for test, blank dimension and testing conditions(stamping velocity, lubrication method and blank holding force, etc).Indirect testing method is also called basic testing method its characteristic is to connect analysis and research on fundamental property and principle of the sheet metal during plastic deformation, and with the plastic deformation parameters of the sheet metal in actual stamping forming, and then to establish the relationship between the indirect testing results(indirect testing value) and the actual stamping forming property (forming parameters). Because the shape and dimension of the specimen and the loading pattern of the indirect testing are different from the actual stamping forming, the deformation characteristics and stress states of the indirect test are different from those of the actual one. So, the results obtained form the indirect test are not the stamping forming parameters, but are the fundamental parameters that can be used to represent the stamping forming property of the sheet metal.