Z形件彎曲沖壓模具設(shè)計(jì)【切斷-彎曲復(fù)合模】【說(shuō)明書(shū)+CAD】,切斷-彎曲復(fù)合模,說(shuō)明書(shū)+CAD,Z形件彎曲沖壓模具設(shè)計(jì)【切斷-彎曲復(fù)合?！俊菊f(shuō)明書(shū)+CAD】,彎曲,曲折,沖壓,模具設(shè)計(jì),切斷,割斷,復(fù)合,說(shuō)明書(shū),仿單,cad 成都紡織高等專(zhuān)科學(xué)校 沖壓模具課程設(shè)計(jì)說(shuō)明書(shū) ——Z形件彎曲模設(shè)計(jì) 院系 機(jī)械系 班級(jí) 模具052班 學(xué)生姓名 韓德平 同組成員 何 強(qiáng) 指導(dǎo)教師 龍 玲 完成日期 2007 年 7 月 7 日 零件簡(jiǎn)圖:如右圖所示 生產(chǎn)批量:大批量 材料:Q235 材料厚度:1.5mm 1. 沖壓件工藝分析 該工件只有切斷和彎曲兩個(gè)工序,材料Q235鋼為軟材料,在彎曲時(shí)應(yīng)有一定的凸凹模間隙.工件的尺寸全部為自由公差,可看作IT14級(jí),尺寸精度較低,普通彎曲就能滿(mǎn)足要求. 2. 沖壓方案的確定 該工件包括切斷和彎曲兩個(gè)工序,可以有以下幾種方案: 方案一:先切斷,后彎曲.采用單工序模生產(chǎn); 方案二:切斷___彎曲復(fù)合沖壓.采用復(fù)合模生產(chǎn); 方案一模具結(jié)構(gòu)簡(jiǎn)單,但需要兩道工序兩副模具,生產(chǎn)效率低,難以滿(mǎn)足該工件大批量生產(chǎn)要求;方案二需一副模具,生產(chǎn)效率高,盡管模具結(jié)構(gòu)較方案一復(fù)雜,但由于零件幾何形狀簡(jiǎn)單,模具制造并不困難.通過(guò)對(duì)上述方案的分析比較,該工件的沖壓生產(chǎn)采用方案二為佳. 3. 主要設(shè)計(jì)計(jì)算 (1) 毛坯尺寸計(jì)算 工件彎曲半徑r>0.5t,故坯料展開(kāi)尺寸公式為： LZ=L直1+ L直2 +L直3 +L彎1+ L彎2 查表3.4.1，當(dāng)r/t=2.5,x=0.39. L直1=14-r-t=14-4-1.5=8.5mm, L直2=40-2t-2r=29mm, L彎1=∏α/180(r+xt)=3.14×90(4+0.39×1.5)/180=7.1984mm, 故LZ=8.5+29+8.5+7.1984+7.1984=60.3968mm (2) 排樣及相關(guān)計(jì)算 采用直排，且無(wú)廢料。坯料尺寸為60.40mm×16mm.查板材標(biāo)準(zhǔn)，選用 沖壓力的計(jì)算 落料力：F落=KLtτb=10920 N τb=350MPa 彎曲力：F自=6.6KBt2σb/r+t=2042.182 N σb=400MPa F校=AP=19600 N 頂件力或壓料力： FD=0.5 F自=1021.91 N 壓力機(jī)公稱(chēng)壓力： F壓=1.2 F校=23520 N (3) 沖壓工序力計(jì)算 根據(jù)沖壓工藝總力計(jì)算結(jié)果，并結(jié)合工件高度，初選開(kāi)式固定臺(tái)壓力機(jī)JH21-25. (4) 工作部分尺寸計(jì)算 ① 凸模圓角半徑： rT=4mm 工作相對(duì)彎曲半徑r/t較小，故凸模圓角半徑rT等于工件的彎曲半徑。 ② 凹模圓角半徑： rA=6mm ∵t≤2mm, ∴rA=(3___6)t=6mm. ③ 凸，凹模間隙： 彎曲模：Z/2=tmax+Ct=1.5+0.075+0.05×1.5=1.7mm 切斷：Z=0.18mm ④ 凹模深度： t=1.5mm,凹模h0值: h0=4mm. ⑤ 橫向尺寸及公差： 凹模：(60.40-8.5)0+σκ=51.900+0.030mm 活動(dòng)凸模：LA=（Lmax-0.75Δ）0+σκ=39.550+0.030 LT=（LA-2）0-Σt=39.55-3.4=36.150-0.020mm 則活動(dòng)凸模尺寸為36.15+1.5=37.250-0.020mm 凸模尺寸：51.90-37.25-1.7-0.18=11.970-0.020mm 4. 模具的總體設(shè)計(jì) （1） 模具類(lèi)型的選擇 由沖壓工藝分析可知，采用復(fù)合沖壓，所以模具類(lèi)型為切斷——彎曲復(fù)合模。 （2） 定位方式的選擇 導(dǎo)料采用導(dǎo)料銷(xiāo)，并采用擋料銷(xiāo)定位，以及采用壓料裝置。 （3） 卸料方式的選擇 采用頂件裝置。 （4） 導(dǎo)向方式的選擇 為了提高模具壽命和工件質(zhì)量，方便安裝調(diào)整，該復(fù)合模采用后側(cè)導(dǎo)柱的導(dǎo)向方式。 5. 主要零部件設(shè)計(jì) （1） 工作零件的結(jié)構(gòu)設(shè)計(jì) ① 活動(dòng)凸模： 結(jié)合工件并考慮加工，將彎曲凸模設(shè)計(jì)成活動(dòng)的。用M8螺釘固定在凸模托板上。，與凸模托板配合按H6/M5，其長(zhǎng)度為60mm。如下圖所示： ② 凸模 由于要先切斷在彎曲，故在凸模上嵌入鑲塊，并采用黏結(jié)劑固定。這樣可以節(jié)約材料，以免全部采用較好材料。鑲塊尺寸為2*5mm。 凸模與上模座采用螺釘固定。選用M6螺釘。，與上模按H6/M5配合。其總長(zhǎng)L=150mm.如下圖所示。 ③ 凹模 凹模與模座用螺釘固定固定。安裝凹模在模架上的位置時(shí)，要依據(jù)計(jì)算壓力中心的數(shù)據(jù)，將壓力中心和模柄中心重合。其輪廓尺寸如下圖所示： ④ 頂件塊 由于要先彎曲左側(cè)部分，其采用頂件裝置。故在凹模內(nèi)裝配頂板。具體尺寸如下圖所示： （2） 模架及其他零部件的選用 模具選用后側(cè)導(dǎo)柱標(biāo)準(zhǔn)模架，可承受較大的沖壓力。為了提高模具 壽命和工件質(zhì)量，方便安裝調(diào)整，該復(fù)合模采用后側(cè)導(dǎo)柱的導(dǎo)向方式。 導(dǎo)柱為32mm×160mm，導(dǎo)套為32mm×105mm×43mm 上模座厚度取45mm，即H上模=45； 壓塊厚度取50mm，即H壓塊=50； 凸模托板厚度取25mm，即H托板=25； 下模座厚度取50mm，即H下模=50； 模具閉合高度H閉=H上模+H壓塊+H托板+H下模+H凸-H入=207mm 可見(jiàn)該模具閉合高度小于所選壓力機(jī)JH21-25的最大裝模高度，可以使用。 6. 模具總裝圖 模具工作過(guò)程：在沖壓前活動(dòng)凸模在橡皮的作用下與凸模端面齊平。沖壓時(shí)，右側(cè)彈簧將坯料壓緊。凸模和活動(dòng)凸模一起往下，凸模將坯料切斷。繼續(xù)往下，由于橡皮產(chǎn)生的的彈壓力大于頂板下方緩沖器產(chǎn)生的彈頂力，推動(dòng)頂板下移，使坯料左端彎曲，當(dāng)頂板接觸下模座后，橡皮壓縮，則凸模相對(duì)于活動(dòng)凸模下移，將坯料右端彎曲成形，當(dāng)壓塊與上模座相碰時(shí)，整個(gè)工件得以校正。當(dāng)上?；爻虝r(shí)，頂件塊將工件頂出，并手工將工件取走，然后將條料送進(jìn)，進(jìn)行下一個(gè)工件的生產(chǎn)。 模具裝配圖如下圖所示： 7．沖壓設(shè)備的選定 通過(guò)校核，選擇開(kāi)式固定臺(tái)壓力機(jī)JH21-25能滿(mǎn)足要求。其主要參數(shù)如下： 標(biāo)稱(chēng)壓力：250KN 標(biāo)稱(chēng)行程：2.8mm 滑塊行程：80mm 行程次數(shù)：100次/min 最大閉合高度：250mm 封閉高度調(diào)節(jié)：50mm 滑塊中心到機(jī)身距離：210mm 工作臺(tái)尺寸（前后×左右）：440mm×700mm 工作臺(tái)孔尺寸：150mm 模柄孔尺寸：40mm×65mm 電動(dòng)機(jī)功率：2.2kw 8．模具的裝配 本模具的裝配先凸，凹模為基準(zhǔn)件，先裝上模，再裝下模。裝配應(yīng)保證間隙均勻。然后裝機(jī)試沖，并根據(jù)試沖結(jié)果做相應(yīng)的調(diào)整。 沖壓成形與板材沖壓 1． 概述 通過(guò)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(chēng)為冷沖壓。只有當(dāng)板材厚度超過(guò)8~100mm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(chēng)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(chē)、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(lèi)基本問(wèn)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(mǎn)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(lái)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(chēng)，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(lái)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(méi)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(guò)程。因此，以拉應(yīng)力作用為主的伸長(zhǎng)類(lèi)沖壓成形過(guò)程多于以壓應(yīng)力作用為主的壓縮類(lèi)成形過(guò)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(guò)程智能化控制的研究工作也在開(kāi)展。人們?cè)趯?duì)沖壓成形過(guò)程有離開(kāi)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(lèi) ? ?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(lèi)。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(lèi)，可以把成形性質(zhì)相同的成形方法概括成同一個(gè)類(lèi)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。基于這樣的分析，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(lái)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(guò)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(mén)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(guò)程對(duì)板材性能的要求進(jìn)行新型材料的開(kāi)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(guò)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(lèi)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(guò)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(guò)于復(fù)雜的因素，利用軸對(duì)稱(chēng)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(guò)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(lái)，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(guò)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(lái)表示板材沖壓性能的基礎(chǔ)性參數(shù)。 Characteristics and Sheet Metal Forming 1． 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 8~100mm. 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 shape?? and 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. 2．Characteristics 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. 3．Categories 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. 4．Raw materials for stamping forming There 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. 5．Stamping forming property of sheet metal and its assessing method The 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.