卡板落料模的設(shè)計(jì)與制造【W(wǎng)形墊板】【說明書+CAD】,W形墊板,說明書+CAD,卡板落料模的設(shè)計(jì)與制造【W(wǎng)形墊板】【說明書+CAD】,卡板落料模,設(shè)計(jì),制造,墊板,說明書,仿單,cad 濟(jì)源職業(yè)技術(shù)學(xué)院 畢 業(yè) 設(shè) 計(jì) 題目 卡板落料模的設(shè)計(jì)與制造 系別 專業(yè) 　　　　 　　　　　　　　 班級(jí) 姓名 學(xué)號(hào) 指導(dǎo)教師 日期 設(shè)計(jì)任務(wù)書 設(shè)計(jì)題目： 卡板落料模的設(shè)計(jì)與制造 設(shè)計(jì)要求： 1.確定沖壓件的排樣方式。 2.有關(guān)計(jì)算及模具設(shè)計(jì)。 3.模具制造工藝編制與裝配。 設(shè)計(jì)進(jìn)度： 1．11月26日－11月30日 查閱收集資料 2．12月1日－12月5日 主要設(shè)計(jì)計(jì)算 3．12月6日－12月14日 結(jié)構(gòu)設(shè)計(jì) 4．12月15日－12月22日 模具的整體設(shè)計(jì) 5．12月23日－12月25日 校核、修改、上交論文 6．12月26日－12月31日 論文答辯 指導(dǎo)教師（簽名）： 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 濟(jì)源職業(yè)技術(shù)學(xué)院 機(jī)電系2007屆畢業(yè)生畢業(yè)設(shè)計(jì)答辯記錄 姓 名 扶清森 專 業(yè) 模具設(shè)計(jì)與制造 班 級(jí) 0401 答辯時(shí)間 答辯地點(diǎn) 設(shè)計(jì)題目 卡板落料模設(shè)計(jì)與制造 1.試述沖裁模刃口尺寸計(jì)算原則？ 答：①落料件尺寸取決于凹模尺寸，沖孔件的尺寸取決于凸模尺寸。 ②考慮刃口的磨損對(duì)沖裁件尺寸的影響。 ③考慮沖裁件精度與模具精度間的關(guān)系。 2．從工藝角度考慮沖裁凸模的分類有哪幾種？ 答：由于沖裁凸模的刃口形狀種類繁多，從工藝角度考慮，可將其分為圓形和非圓形兩種。 3．確定加工余量的方法有哪幾種？ 答：①查表法 ②分析計(jì)算法 ③經(jīng)驗(yàn)估計(jì)法 4.模具設(shè)計(jì)的特點(diǎn)是什么？ 答：①拉深工藝計(jì)算要求有較高的準(zhǔn)確性，拉深凸模長度的決定必須滿足工件拉深高度的要求，且拉深凸模上必須設(shè)計(jì)通氣孔。 ②在有凸緣的拉深工序過程中，工件的高度取決于上模的行程，使用中為便于模具調(diào)整，最好在模具上設(shè)計(jì)限位柱，當(dāng)壓力機(jī)滑塊在下死點(diǎn)位置時(shí)，模具應(yīng)在限程的位置閉合。 ③拉深時(shí)由于工作行程較大，故對(duì)控制壓邊力用的彈性元件的壓縮量應(yīng)認(rèn)真計(jì)算。 ④壓邊圈與毛坯接觸的一面要平整，不應(yīng)有孔或槽，否則拉深時(shí)毛坯起皺會(huì)陷到孔或槽里，引起拉裂。 5．模具常用的裝配方法有哪幾種？ 答：①互換裝配法 ②分組互換裝配法 ③修配裝配法 ④調(diào)整裝配法 記錄教師（簽名）： 1 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 目 錄 摘要 .1 前言 .2 1 沖壓件的工藝分析 .3 1.1 排樣方法的確定 .4 1.2 搭邊值的采用 .5 2 沖壓力的計(jì)算 .6 2.1 沖裁力 .6 2.2 卸料力 .6 2.3 頂出力 .6 3 壓力中心的確定 .8 4 計(jì)算凸、凹模的刃口尺寸 .9 5 模具總體設(shè)計(jì)及主要零部件設(shè)計(jì) .13 6 沖壓設(shè)備的選擇 .15 7 模具總體設(shè)計(jì) .17 7.1 模具類型的選擇和定位方式的選擇 .17 7.2 卸料出件方式的選擇 .17 7.3 導(dǎo)向方式的選擇 .18 8 模具材料的選用及其他零部件的設(shè)計(jì) .19 9 模具零件加工工藝 .21 10 模具的裝配和沖裁模具的試沖 .22 10.1 模具的裝配 .22 10.2 沖裁模具的試沖 .23 總結(jié) .25 致謝 .26 參考文獻(xiàn) .27 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 1 摘要 模具生產(chǎn)的工藝水平及科技含量的高低，已成為衡量一個(gè)國家科技與產(chǎn)品制造水平的重 要標(biāo)志，它在很大程度上決定著產(chǎn)品的質(zhì)量、效益、新產(chǎn)品的開發(fā)能力，決定著一個(gè)國家制 造業(yè)的國際競(jìng)爭(zhēng)力，因此這次我們的畢業(yè)設(shè)計(jì)要求設(shè)計(jì)一個(gè)模具以便檢驗(yàn)自己所學(xué)模具有關(guān) 方面的知識(shí)是否牢固。 在這次設(shè)計(jì)中根據(jù)所給題目的要求，我首先對(duì)沖壓件進(jìn)行了分析，分析該零件的尺寸精 度得出用一般精度的模具即可滿足零件精度的要求，再從零件的形狀、尺寸標(biāo)注及生產(chǎn)批量 等情況看，我選擇了以下方案。 根據(jù)對(duì)零件的綜合分析，在本人這次設(shè)計(jì)中我設(shè)計(jì)的模具是卡板落料模，主要介紹的是 模具的沖裁，沖壓生產(chǎn)中應(yīng)用最廣泛的工序之一。材料為 30 鋼板，厚度 t=0.3mm。傳統(tǒng)的 加工方法為落料。我的加工方法比較簡單。由于材料和厚度的原因，我采用的加工方法為： 采用單工序落料模進(jìn)行加工。 關(guān)鍵詞：落料模 沖裁 沖壓模具 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 2 前言 隨著經(jīng)濟(jì)總量和工業(yè)產(chǎn)品技術(shù)的不斷發(fā)展，各行各業(yè)對(duì)模具的需求量越來越大，技術(shù)要 求也越來越高。業(yè)內(nèi)專家認(rèn)為，雖然模具種類繁多，但在“十一五”期間其發(fā)展重點(diǎn)應(yīng)該是 既能滿足大量需要，又具有較高的技術(shù)含量，特別是目前國內(nèi)尚不能自給、需大量進(jìn)口的模 具和能代表發(fā)展方向的大型、精密、復(fù)雜、長壽命模具。又由于模具標(biāo)準(zhǔn)件的種類、數(shù)量、 水平、生產(chǎn)集中度等對(duì)整個(gè)模具行業(yè)的發(fā)展有重大影響。因此，一些重要的模具標(biāo)準(zhǔn)件也必 須重點(diǎn)發(fā)展，而且其發(fā)展速度應(yīng)快于模具的發(fā)展速度，這樣才能不斷提高我國的模具標(biāo)準(zhǔn)化 水平，從而提高模具質(zhì)量，縮短模具生產(chǎn)周期及降低成本。由于我國的模具產(chǎn)品在國際市場(chǎng) 上占有較大的價(jià)格優(yōu)勢(shì)，因此對(duì)于出口前景好的模具產(chǎn)品也應(yīng)作為重點(diǎn)來發(fā)展。而且應(yīng)該是 目前已有一定基礎(chǔ)，有條件、有可能發(fā)展起來的產(chǎn)品。如： 1.大型精密塑料模具 塑料模具占我國模具總量的比例正逐年上升，發(fā)展?jié)摿薮蟆?目前雖然已有相當(dāng)技術(shù)基礎(chǔ)并正在快速發(fā)展，但技術(shù)水平與國外仍有較大差距，總量也供不 應(yīng)求，每年進(jìn)口幾億美元。 2.主要模具標(biāo)準(zhǔn)件 目前國內(nèi)已有較大產(chǎn)量的模具標(biāo)準(zhǔn)件主要是模架、導(dǎo)向件、推桿 推管、彈性元件等。這些產(chǎn)品不但國內(nèi)配套大量需要，出口前景也很好，應(yīng)繼續(xù)大力發(fā)展。 雖然如此，我國的沖壓模具設(shè)計(jì)制造能力與市場(chǎng)需要和國際先進(jìn)水平相比仍有較大差距。 這些主要表現(xiàn)在高檔轎車和大中型汽車覆蓋件模具及高精度沖模方面，無論在設(shè)計(jì)還是加工 工藝和能力方面，都有較大差距。轎車覆蓋件模具，具有設(shè)計(jì)和制造難度大，質(zhì)量和精度要 求高的特點(diǎn)，可代表覆蓋件模具的水平。雖然在設(shè)計(jì)制造方法和手段方面已基本達(dá)到了國際 水平，模具結(jié)構(gòu)功能方面也接近國際水平，在轎車模具國產(chǎn)化進(jìn)程中前進(jìn)了一大步，但在制 造質(zhì)量、精度、制造周期等方面，與國外相比還存在一定的差距。 標(biāo)志沖模技術(shù)先進(jìn)水平的多工位級(jí)進(jìn)模和多功能模具，是我國重點(diǎn)發(fā)展的精密模具品種。 有代表性的是集機(jī)電一體化的鐵芯精密自動(dòng)閥片多功能模具，已基本達(dá)到國際水平。 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 3 1 沖壓件的工藝分析 生產(chǎn)批量：大批量 材料： 鋼30 材料厚度： m. 圖 1 卡板 表 1.1 兩孔中心距離公差 一般精度（模具） 較高精度（模具） 孔距基本尺寸 材料厚度 t50150350150301.2.8.212.0.3.004.6.01.45.5.8.2.62.03.40.10.5. 分析該零件的尺寸精度，查表 1.1 其兩孔中心距的尺寸及公差為 ，用一般精m2.8 度的模具可達(dá)到的兩孔中心距離公差為 ，即可滿足零件的精度要求。從零件的形m15.0 狀、尺寸標(biāo)注及生產(chǎn)批量等情況看，也均符合沖裁的工藝要求，并且只需一次落料即可，故 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 4 采用單工序落料模進(jìn)行加工。 1.1 排樣方法的確定 常用的排樣方法有三種： （1）有廢料排樣：指沿工件全部外形沖裁，工件與工件、工件與條料邊緣都留有搭邊， 此種排樣的缺點(diǎn)是材料利用率低，但有了搭邊就能保證沖裁件的質(zhì)量，模具壽命也高。 （2）少廢料排樣：指模具只沿著工件部分外形輪廓沖裁，只有局部搭邊的存在。 （3）無廢料排樣：指工件與工件之間及工件與條料側(cè)邊之間均無搭邊的存在，模具刃口 沿條料順序切下，直接獲得工件。 少、無廢料排樣的缺點(diǎn)是工件質(zhì)量差，模具壽命不高，但這兩種排樣可以節(jié)省材料，還 具有簡化模具結(jié)構(gòu)、降低沖裁力和提高生產(chǎn)率等優(yōu)點(diǎn)。并且工件須具有一定的形狀才能采用 少、無廢料排樣。上述三類排樣方法，按工件的外形特征主要分為直排、斜排、直對(duì)排、斜 對(duì)排、混合排、多行排等形式。 根據(jù)本零件的特點(diǎn)，適合采用有廢料直排的方式,這樣不僅使沖出的零件達(dá)到要求，有 可以盡可能大的提高材料的利用率。 采用直排有廢料排樣方式所示： 圖 2 排樣方式 計(jì)算沖裁件的面積 :A 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 5 22 2 319071471826 mA 1.2 搭邊值的采用 表 1.2 沖裁金屬材料的搭邊值 手送料 圓形 非圓形 往復(fù)送料 自動(dòng)送料 料厚 a1a1a1a1 1 1.5 1.5 2 1.5 3 2 12 2 1.5 2.5 2 3.5 2.5 3 2 23 2.5 2 3 2.5 4 3.5 34 3 2.5 3.5 3 5 4 4 3 45 4 3 5 4 6 5 5 4 56 5 4 6 5 7 6 6 5 68 6 5 7 6 8 7 7 6 8 以 上 7 6 8 7 9 8 8 7 查表 1.2 的最小搭邊值： , ma25.1 條料寬度： b120 進(jìn)距： mh5.3.34 一個(gè)進(jìn)距的材料利用率： %75105.31209%2mbhnA 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 6 2 沖壓力的計(jì)算 2.1 沖裁力 該模具采用彈性卸料和上出料方式，采用平刃口凸模和凹模沖裁時(shí)，其沖裁力的計(jì)算式 如下： bLtFN 其中 m34.69721684216 mt3.0 abMP5 故 NF3104.5.4.369 2.2 卸料力 從凸模上卸下緊箍著的材料所需的力稱為卸料力，影響卸料力的因素很多如材料的種類， 材料的厚度，沖裁間隙，零件的尺寸以及潤滑情況等。這些力通常采用經(jīng)驗(yàn)公式進(jìn)行計(jì)算如： FK卸卸 查表 3.3 得 05.卸 N33107.214.卸 2.3 頂出力 FK頂頂 表 2.1 卸料力、推件力和頂出力因數(shù) 沖裁材料 K 卸 K 推 K 頂 純銅、黃銅 0.020.06 0.030.09 鋁、鋁合金 0.0250.08 0.030.07 0.1 0.060.075 0.1 0.14 0.10.5 0.0450.055 0.065 0.08 0.52.5 0.040.05 0.050 0.06鋼 材料 厚度 mm 2.56.5 0.030.04 0.040 0.05 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 7 6.5 0.020.03 0.025 0.03 查卸料力、推件力和頂出力因數(shù)表 3.3 得 08.頂K NF331421.508. 頂 選擇沖床時(shí)的總沖壓力：KNF6.2推頂總 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 8 3 壓力中心的確定 沖裁模的壓力中心就是沖裁力合力的作用點(diǎn)。沖壓時(shí)，模具的壓力中心一定要與沖床滑 塊的中心線重合。否則滑塊就會(huì)承受偏心載荷，使模具歪斜，間隙不均勻，從而導(dǎo)致沖床滑 塊與導(dǎo)軌和模具的不正常磨損，降低沖床和模具的壽命。所以在模具設(shè)計(jì)時(shí)，必須要確定模 具的壓力中心，并使其通過模柄的軸線，從而保證模具壓力中心與沖床滑塊中心重合。 對(duì)稱形狀的 工件，其壓力中心位于輪廓圖形的幾何中心 O 點(diǎn)壓力中心圖 3.1 確定模具壓力中心 按比例畫出工件形狀，將工件輪廓線分成 基本線段，并選定坐521.l、 標(biāo)系 ，如圖 3 所示，因工件左右對(duì)稱，其壓力中心一定在對(duì)稱軸 上，即 。計(jì)算xOy y0 x.0 圖 3 壓力中心 ;814261 mml 01y 0732 m5.8742 ;43ly4.21sin13mmy 69.274cosin174 ;5324l;85ly345lllyyy4.16543210 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 9 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 10 4 計(jì)算凸、凹模的刃口尺寸 表 4.1 落料、沖孔模刃口使用間隙 材料名 稱 45退 火8,7T 磷青銅（硬） 鈹青銅（硬） 10、15、20 冷軋鋼帶 30 鋼板 硅鋼板 、235Q1 鋼板 08、10、15 鋼板 銅母線 鋁母線 防銹鋁 軟鋁 L2L6 力學(xué)性 能 MPa HBSb6019MPaHBSb60419MPaHBSb40317PaHBSb307 初始間隙 Z 厚度 t minZaxminZaxminaxminZax 0.1 0.015 0.035 0.01 0.03 * * 0.2 0.025 0.045 0.015 0.035 0.01 0.03 * 0.3 0.04 0.06 0.03 0.05 0.02 0.04 0.01 0.03 0.5 0.08 0.10 0.06 0.08 0.04 0.06 0.025 0.045 0.8 0.13 0.16 0.10 0.13 0.07 0.10 0.045 0.075 1.0 0.17 0.20 0.13 0.16 0.10 0.13 0.065 0.095 1.2 0.21 0.24 0.16 0.19 0.13 0.16 0.075 0.105 1.5 0.27 0.31 0.21 0.25 0.15 0.19 0.10 0.14 1.8 0.34 0.38 0.27 0.31 0.20 0.24 0.13 0.17 2.0 0.38 0.42 0.30 0.34 0.22 0.26 0.14 0.18 2.5 0.49 0.55 0.39 0.45 0.29 0.35 0.18 0.24 3.0 0.62 0.68 0.49 0.55 0.36 0.42 0.23 0.29 3.5 0.73 0.81 0.58 0.66 0.43 0.51 0.27 0.35 4.0 0.86 0.94 0.68 0.76 0.50 0.58 0.32 0.40 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 11 4.5 1.00 1.08 0.78 0.86 0.58 0.66 0.37 0.45 5.0 1.13 1.23 0.90 1.00 0.65 0.75 0.42 0.52 6.0 1.40 1.5 1.10 1.20 0.82 0.92 0.53 0.63 8.0 2.00 2.12 1.60 1.72 1.17 1.29 0.76 0.88 10 2.60 2.72 2.10 2.22 1.56 1.68 1.02 1.04 12 3.30 3.42 2.60 2.72 1.97 2.09 1.30 1.42 查落料、沖孔模的初始間隙經(jīng)驗(yàn)數(shù)據(jù)表 4.1 得間隙值 ,03.minZ.05maxZ 表 4.2 因數(shù) x 非圓形 x 值 圓形 X 值 1 0.75 0.5 0.75 0.5 材料厚度 mt 工件公差 m 1 0.16 0.170.35 0.36 0.16 0.16 12 0.20 0.210.41 0.42 0.20 0.20 24 0.24 0.250.49 0.50 4 0.30 0.210.59 0.60 0.30 0.30 查表得因數(shù) 5.0 x 表 4.3 沖裁和拉深件未注公差尺寸的極限偏差 m 尺寸的類型 基本尺寸 包容表面 被包容表面 孔中心距 +0.25 -0.25 36 +0.30 -0.30 15.0 610 +0.36 -0.36 1018 +0.43 -0.43 2. 1830 +0.52 -0.52 3050 +0.62 -0.62 31.0 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 12 5080 +0.74 -0.74 80120 +0.87 -0.87 435.0 120180 +1.00 -1.00 7. 對(duì)零件圖中未注公差的尺寸，查表 4.3 查出其極限偏差 , ， 。 m087.1643.0m062.043.17 本零件因形狀比較復(fù)雜，且為薄材料，為了保證凸、凹模間的間隙值，必須采用凸、凹 模配合加工的方法?，F(xiàn)以凹模磨損后的尺寸變化情況，將零件圖中各尺寸進(jìn)行分類： A 類尺寸： ， ， B 類尺寸：087.16062.34043.17 43.01 C 類尺寸： 2 凹模刃口尺寸計(jì)算如下： 40max Aj m2.487.0515.16凹 16.046.093.3凹 .0.077凹 4minxBjm01.03.245.14凹 8.minCj 05.82.045182凹 凸模的刃口尺寸按凹模的實(shí)際尺寸配制，并保證雙面間隙 。m05.3. 凹模的外形尺寸：參考式取凹模厚度 ，凹模的壁厚 。mHc4 凹模的零件圖見圖 4。 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 13 圖 4 凹模 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 14 5 模具總體設(shè)計(jì)及主要零部件設(shè)計(jì) 如圖 5 所示的模具總圖。 19876543120987654321 圖 5 總裝圖 該模具為癥狀下頂出單工序落料模，條料的送進(jìn)，由兩個(gè)導(dǎo)料銷 1 控制其方向，由固定 擋料銷 12 控制其進(jìn)距。卸料采用彈性卸料裝置，將廢料從凸模上卸下。同時(shí)有裝在模座之 下的頂出裝置實(shí)現(xiàn)上出件，通過調(diào)整螺母 19 壓縮橡膠 17，可調(diào)整頂出力。由于該彈性頂出 裝置在沖裁時(shí)能壓住工件，并及時(shí)地將工件從凹模內(nèi)頂出，因此可使沖出的工件表面平整。 適用于厚度較薄的中、小工件的沖裁。 卸料彈簧的設(shè)計(jì)計(jì)算： 1.根據(jù)模具結(jié)構(gòu)初定 6 根彈簧，每根彈簧分擔(dān)的卸料力為：NnF4027卸 2.根據(jù)預(yù)壓力 和模具的結(jié)構(gòu)尺寸，選出序號(hào) 5761 的彈簧，其最大工作負(fù)荷預(yù) 為 ,且大于 。106 3.效驗(yàn)是否滿足 。經(jīng)過計(jì)算可得下列數(shù)據(jù)如表 5.1總s1 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 15 表 5.1 效驗(yàn)數(shù)據(jù)表 序號(hào) 0H110HsNFs460預(yù)預(yù) 修 磨工 作預(yù)總 ss5742.38.4 3.1786932090.5.717.413523638.2.4630.7 注： msmts 6,.10修 磨工 作 由上述表中數(shù)據(jù)可知，序號(hào) 5961 的彈簧均滿足 ，根據(jù)模具結(jié)構(gòu)確定使用總s1 59 號(hào)彈簧。該彈簧規(guī)格為： 外經(jīng)： 鋼絲直徑：D36d0.5 自由高度： mH80 裝配高度： ms63172預(yù) 模具選用后側(cè)導(dǎo)柱標(biāo)準(zhǔn)模架： 上模座： 4520/ BL 下模座： Hm 導(dǎo)柱： 1632/d 導(dǎo)套： 4305/D 模架的閉合高度： 70 墊板厚度： m1 凸模固定板厚度： 6 彈簧露出高度： m4103為 卸料板厚度： 14 模具的閉合高度： mH185021365模 6 沖壓設(shè)備的選擇 沖壓設(shè)備類型的選擇：根據(jù)所要完成的沖壓工藝的性質(zhì)，生產(chǎn)批量的大小，沖壓件的幾 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 16 何尺寸和精度要求等來選擇設(shè)備的類型。 對(duì)于中小型的沖栽件，彎曲件或拉深件的生產(chǎn)，主要應(yīng)用開式機(jī)械壓力機(jī)，雖然開式?jīng)_ 床的剛性差，在沖壓力的作用下床身的變形能夠破壞沖裁間隙分布，降低模具的壽命或沖裁 件的質(zhì)量?？墒牵捎谒峁┝藰O其方便的操作條件和非常容易安裝機(jī)械化附屬裝置的特點(diǎn)， 使它成為目前中、小型沖壓設(shè)備的主要形式。 對(duì)于大、中型沖壓件的生產(chǎn)，多采用閉式結(jié)構(gòu)形式的機(jī)械壓力機(jī)，其中有一般用途的通 用壓力機(jī)，也有臺(tái)面較小而剛度大的擠壓壓力機(jī)、精度機(jī)等。在大型拉深件的生產(chǎn)中，應(yīng)盡 量選用雙動(dòng)拉深壓力機(jī)，因其可使所用模具結(jié)構(gòu)簡單，調(diào)整方便。 在小批量生產(chǎn)中，尤其是是大型沖壓件的生產(chǎn)多采用液壓機(jī)。液壓機(jī)沒有固定的行程， 不會(huì)因?yàn)榘辶虾穸茸兓d，而且在需要很大的施力行程加工時(shí)，與機(jī)械壓力機(jī)相比具有 明顯的優(yōu)點(diǎn)。但是，液壓機(jī)的速度小，生產(chǎn)率低，而且零件的尺寸精度有時(shí)因受到操作因素 的影響而不十分穩(wěn)定。 磨擦壓力機(jī)具有結(jié)構(gòu)簡單、造價(jià)低廉、不易發(fā)生超負(fù)荷損壞等特點(diǎn)，所以在小批量生產(chǎn) 中常用來完成彎曲、成形等沖壓工序。但是，摩擦壓力機(jī)的行程次數(shù)少，生產(chǎn)率低，而且操 作不太方便。 在大批量或形狀復(fù)雜零件的大量生產(chǎn)中，應(yīng)盡量選用高速壓力機(jī)或多工位自動(dòng)壓力機(jī)。 沖壓設(shè)備規(guī)格的確定。 在沖壓設(shè)備的類型選定以后，應(yīng)該進(jìn)一步根據(jù)沖壓件的尺寸、模具的尺寸和沖壓力來確 定設(shè)備的規(guī)格。 所選壓力機(jī)的公稱壓力必須大于沖壓所需的總沖壓力，即： Fl總壓 機(jī) 1壓力機(jī)的行程應(yīng)適當(dāng)。由于壓力機(jī)的行程影響到模具的張開高度，因此對(duì)于沖裁、 彎曲等模具，其行程不宜過大，以免發(fā)生凸模與導(dǎo)板分離（導(dǎo)板模）或滾珠導(dǎo)向裝置脫開的 不良后果。對(duì)于拉深模，壓力機(jī)的行程至少應(yīng)大于成品零件高度的兩倍以上，以保證毛坯的 放進(jìn)和成形零件的取出。 2所選壓力機(jī)的閉合高度應(yīng)與沖模與沖模的閉合高度相適應(yīng)。即滿足：沖模的閉合高 度介于壓力機(jī)的最大閉合高度和最小閉合高度之間。 3壓力機(jī)的工作臺(tái)面的尺寸必須大于模具下模座的外形尺寸，并且還要留有安裝固定 的余地。但在過大的臺(tái)面上安裝過小尺寸的沖模時(shí)，對(duì)工作臺(tái)的受力條件也是不利的。 選用開式雙柱可傾壓力機(jī) ： 1623J 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 17 公稱壓力： KN160 滑塊行程： m5 最大閉合高度： 2 閉合高度調(diào)節(jié)量： 4 滑塊中心線至床身距離： 160 工作臺(tái)尺寸： m530 墊板厚度： 4 模柄孔尺寸： 6 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 18 7 模具總體設(shè)計(jì) 7.1 模具類型的選擇和定位方式的選擇 模具類型分為三種分別是：單工序模、復(fù)合模和級(jí)進(jìn)模。 單工序模又稱簡單沖裁模，是指在壓力機(jī)一次行程內(nèi)只完成一種沖裁工序的模具，如落 料模、沖孔模、切斷模切口模等。 復(fù)合模是指在一次壓力機(jī)的行程中在模具的同一工位上同時(shí)完成兩道或兩到以上不同沖 裁工序的模具。復(fù)合模是一種多工序沖裁模，它在結(jié)構(gòu)上的主要特征是有一個(gè)或幾個(gè)具有雙 重作用的工作零件凸凹模，如落料沖孔復(fù)合模中有一個(gè)既能作落料凸模又能作沖孔凹模 的凸凹模。 由沖壓工藝分析可知，該模具采用級(jí)進(jìn)沖壓，所以模具類型為級(jí)進(jìn)模。 定位方式的選擇通俗的說既是選擇定位零件。定位零件的作用是使坯料或工序件在模具 上有正確的位置，定位零件的結(jié)構(gòu)形式很多，用于對(duì)條料進(jìn)行定位的定位零件有擋料銷、導(dǎo) 料銷、導(dǎo)料板、側(cè)壓裝置、導(dǎo)正銷、側(cè)刃等，用于對(duì)工序進(jìn)行定位的定位零件有定位銷、定 位板等。 定位零件基本上都已標(biāo)準(zhǔn)化，可根據(jù)坯料和工序件形狀、尺寸、精度及模具的結(jié)構(gòu)形式 與生產(chǎn)效率要求等選用相應(yīng)的標(biāo)準(zhǔn)。 因?yàn)樵撃＞卟捎檬菞l料，控制條料的送進(jìn)方向采用導(dǎo)料板，無側(cè)壓裝置?？刂茥l料的送 進(jìn)步距采用擋料銷初定距，導(dǎo)正銷精定距。而第一件的沖壓位置因?yàn)闂l料長度有一定余量， 可以靠操作工目測(cè)定。 7.2 卸料出件方式的選擇 卸料與出件裝置的作用是當(dāng)沖模完成一次沖壓之后，把沖件或廢料從模具工作零件上卸 下來，以便沖壓工作繼續(xù)進(jìn)行。通常，把沖件或廢料從凸模上卸下來稱為卸料。 卸料裝置按卸料的方式分為固定卸料裝置彈性卸料裝置和廢料切刀三種。固定卸料裝 置，固定卸料裝置僅由固定卸料板構(gòu)成，一般安裝在下模的凹模上；彈性卸料裝置由卸料板、 卸料螺釘和彈性元件（彈簧或橡膠）組成；彈性卸料裝置可安裝于上?；蛳履?，依靠彈簧或 橡膠的彈力來卸料，卸料力不太大但沖壓時(shí)可兼起壓料作用，故多用于沖裁料薄及平面度要 求較高的沖件；廢料切刀是在沖裁過程中沖裁廢料切斷成數(shù)塊，從而實(shí)現(xiàn)卸料的一種卸料零 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 19 件。 出件裝置的作用是從凹模內(nèi)卸下沖件或廢料。我們通常把裝在上模內(nèi)的出件裝置稱為推 件裝置；把裝在下模內(nèi)的稱為頂件裝置。 綜合考慮該模具的結(jié)構(gòu)和使用方便，以及工件料厚為 1.2mm，相對(duì)較薄，卸料力也比較 小，故可采用彈性卸料。 又因?yàn)槭羌?jí)進(jìn)模生產(chǎn)。所以采用下出件比較便于操作與提高生產(chǎn)效率。 7.3 導(dǎo)向方式的選擇 在沖壓過程中，導(dǎo)向結(jié)構(gòu)一般情況下直接與模架聯(lián)系在一起，該模具采用中間導(dǎo)柱的導(dǎo) 向方式，提高模具壽命和工件質(zhì)量，方便安裝調(diào)整，故該級(jí)進(jìn)模采用中間導(dǎo)柱的導(dǎo)向方式。 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 20 8 模具材料的選用及其他零部件的設(shè)計(jì) 模具材料的選用 冷沖模用鋼應(yīng)具有的力學(xué)性能： 1.應(yīng)具有較高的變形抗力； 2.應(yīng)具有較高的斷裂抗力； 3.應(yīng)具有較高的耐磨性及抗疲勞性能； 4.應(yīng)具有較高的冷熱加工工藝性。 冷沖模零件材料選用原則： 1.要選擇能滿足模具工作要求的最佳綜合性能的材料； 2.要針對(duì)模具失效形式選用鋼材； 3.要根據(jù)制品的批量大小，以最低成本的選材原則選材； 4.要根據(jù)沖模零件的作用選擇材料； 5.要根據(jù)沖模精度程度選擇鋼材。 綜合各種材料進(jìn)行比較及材料的用途查下列表 8.1 和 8.2 可選擇 GrWMn 為冷沖模工作零 件所用的鋼材。 表 8.1 冷沖模工作零件材料的選用 零件名稱 使用條件 選用材料 形狀簡單，沖裁材料厚 度 t 小于等于 3mm，中小 批量生產(chǎn)的沖裁 T8、T8A、T10、T10A 沖裁件厚度 t 小于等于 3mm，形狀復(fù)雜，或沖裁 厚度 t 大于 3mm 的中小 批量沖裁 Gr12、GrWMn、GGr15、G r12MoV 要求批量較大，使用壽 命較長的沖裁模 W18Gr4V、Gr4W2MoV、W6 Mo5GrV2、YG15、YG20 凸模，凹模，凸凹模， 凸、凹模鑲塊，連續(xù)模， 側(cè)刃凸模 需要加熱沖裁模 3Gr2W8V、5GrNiMo、6Gr 4Mo3NiWV 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 21 選擇說明：在選擇沖裁凸模、凹模材料時(shí)，應(yīng)根據(jù)模具的工作條件和失效特點(diǎn)，量材而 用。如形狀簡單、尺寸較小、受力較小的凸、凹模，只需要熱處理工藝適當(dāng)。性能可以滿足 使用，生產(chǎn)批量不大時(shí)，可選用碳素工具鋼，這樣可以降低成本；反之，就應(yīng)該選用變形較 小，耐磨性高的合金工具鋼。對(duì)于大、中型沖裁模，其材料成本與模具總成本 10%18%左右， 故應(yīng)選用變形小、耐磨性高的合金工具鋼較適宜。 表 8.2 冷沖模輔助材料 零件名稱 選用材料 熱處理 硬度 HRC 上模座、下模座 HT2040HT2547、 ZG25、 ZG35A3、A 5 模柄 A3、A5 凸模固定板、凸、 凹模固定板 A3、A5 側(cè)面導(dǎo)板 45 淬火 4348 導(dǎo)柱 20 滲碳 0.81 5862 導(dǎo)套 20 淬火 5860 導(dǎo)正銷、定位銷 T7、T8 淬火 5256 擋料銷、擋料板 45 淬火 4548 墊板、定位板 45、T7A 淬火 4348 螺母、墊圈 A3 固定螺栓、螺釘 A3、45 銷釘 45 淬火 4548 頂桿、推桿 45 淬火 4348 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 22 9 模具零件加工工藝 本副沖裁模，模具零件加工的關(guān)鍵在工作零件，固定板以及卸料板，若采用線切割 加工技術(shù)，這些零件的加工就變得相對(duì)簡單，具體內(nèi)容見表 9.1。 表 9.1 落料凸模的加工工藝過程 工序號(hào) 工序名稱 工序內(nèi)容 1 備料 將毛坯鍛成長方體 1283872 2 熱處理 退火 3 刨 刨 6 面，互為直角留單邊余量 0.5mm 4 熱處理 調(diào)質(zhì) 5 磨平面 磨 6 面，互成直角 6 鉗工劃線 劃出各孔位置線 7 加工螺釘孔、安 裝孔及穿絲孔 按位置加工螺釘孔、銷釘孔及穿絲孔 等 8 熱處理 按熱處理工藝，淬火回火達(dá)到 5862HRC 9 磨平面 精磨上、下平面 10 線切割 按圖線切割，輪廓達(dá)到尺寸要求 11 鉗工精修 全面達(dá)到設(shè)計(jì)要求 12 檢驗(yàn) 凹模、固定板以及卸料板都屬于板類零件，其加工工藝比較規(guī)范。凹模的加工過程與落 料凸模的加工過程完全類似，見表 9.1，在此不再重復(fù)。 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 23 10 模具的裝配和沖裁模具的試沖 10.1 模具的裝配 根據(jù)級(jí)進(jìn)模裝配要點(diǎn)，選凹模作為裝配基準(zhǔn)件，先裝下模，再裝上模，并調(diào)整間隙、試 沖、返修，具體裝配見表 10.1。 表 10.1 級(jí)進(jìn)模的裝配 序號(hào) 工序 工藝說明 1 凸、凹模 預(yù)配 （1）裝配前仔細(xì)檢查各凸模形狀以及凹模形孔，是否符合圖紙要求尺 寸精度、形狀。 （2）將各凸模分別與相應(yīng)的凹模孔相配，檢查其間隙是否加工均勻。 不合適者應(yīng)重新修磨或更換。 2 凸模裝配 以凹模孔定位，將各凸模分別壓入凸模固定板 7 的形孔中，并擰緊牢 固 3 裝配下模 （1） 在下模座 1 上劃中心線，按中心預(yù)裝凹模 2、導(dǎo)料板 3； （2） 在下模座 1、導(dǎo)料 3 上，用已加工好的凹模分別確定其螺孔位 置，并分別鉆孔，攻絲 （3） 將下模座 1、導(dǎo)料板 3、凹模 2、活動(dòng)擋料銷 13、彈簧 14 裝在 一起，并用螺釘緊固，打入銷釘 4 裝配上模 （1） 在已裝好的下模上放等高墊鐵，再在凹模中放入 0.12mm 片，然 后將凸模與固定板的組合裝入凹模； （2） 預(yù)裝上模座，劃出與凸模固定板相應(yīng)螺孔。銷孔位置并鉆絞螺 孔、銷孔； （3） 用螺釘將固定板組合、墊板 8、上模座連接在一起，但不要擰 緊； （4） 將卸料板 5 套裝在已裝入固定板的凸模上，裝上橡膠 9 和卸料 螺釘 6，并調(diào)節(jié)橡膠的預(yù)壓量，使卸料板高出凸模下端約 1mm； （5） 復(fù)查凸、凹模間隙并調(diào)整合適后，緊固螺釘； （6） 安裝導(dǎo)正銷 4、承料板 15； 切紙檢查，合適后打入銷釘。 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 24 5 試沖調(diào)整 裝機(jī)試沖并根據(jù)試沖結(jié)果作相應(yīng)調(diào)整 10.2 沖裁模具的試沖 模具裝配以后，必須在生產(chǎn)條件下進(jìn)行試沖。通過試沖可以發(fā)現(xiàn)模具設(shè)計(jì)和制造的不 足，并找出原因給與糾正。并能夠?qū)δ＞哌M(jìn)行適當(dāng)?shù)恼{(diào)整和修理，直到模具正常工作中沖出 合格的制件為止。 沖裁模具經(jīng)試沖合格后，應(yīng)在模具模座正面打上編號(hào)、沖模圖號(hào)、制件號(hào)、使用壓力 機(jī)型號(hào)、制造日期等。并涂油防銹后經(jīng)檢驗(yàn)合格入庫。 沖裁模具試沖時(shí)常見的缺陷、產(chǎn)生原因和調(diào)整方法見表 10.2。 表 10.2 試沖時(shí)常見的缺陷、產(chǎn)生原因和調(diào)整方法 缺陷 產(chǎn)生原因 調(diào)整方法 沖件毛刺過大 1.刃口不鋒利或淬火硬度不 夠 2間隙過大或過小，間隙不 均勻 1修磨刃口使其鋒利 2重新調(diào)整間隙，使其均勻 沖件不平整 1凸模有倒錐，沖件從孔中 通過時(shí)被呀彎 2頂出件與頂出器接觸零件 面積大小 1修磨凹?？祝コ龑?dǎo)錐現(xiàn) 象 2更換頂出桿，加大與零件 的接觸面積 尺寸超差和形狀不準(zhǔn)確 凸模、凹模形狀及尺寸精度 差 修整凸模、凹模形狀及尺寸， 使其達(dá)到形狀及尺寸精度要 求 凸模折斷 1沖裁時(shí)產(chǎn)生側(cè)壓力 2卸料板傾斜 1在模具上設(shè)置擋塊抵消側(cè) 向力 2修整卸料板或使凸模增加 導(dǎo)向裝置 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 25 凹模被脹裂 1凹?？子械瑰F度形象 2凹?？變?nèi)卡住廢料 1修磨凹?？?，消除倒錐現(xiàn) 象 2修抵凹模孔高度 凸、凹模刃口相咬 1.上、下模座，固定板、凹 模、墊板等零件安裝基面不 平行 2.凸、凹模錯(cuò)位 3.凸模、導(dǎo)柱、導(dǎo)套與安裝 基面不垂直 4導(dǎo)向精度差，導(dǎo)柱、導(dǎo)套 配合間隙過大 1調(diào)整有關(guān)兩件重新安裝 2重新安裝凸、凹模，使之 對(duì)正 3調(diào)整其垂直度重新安裝 4更換導(dǎo)柱、導(dǎo)套 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 26 總結(jié) 經(jīng)過整整一個(gè)月的搜集整理資料和在指導(dǎo)老師的精心幫助下，我的畢業(yè)設(shè)計(jì)終于成功 定稿了。 在這次的畢業(yè)設(shè)計(jì)中，我發(fā)現(xiàn)了在模具方面我還有很多的薄弱環(huán)節(jié)需要我的鞏固學(xué)習(xí)， 尤其是在計(jì)算凸、凹模的刃口尺寸方面我還應(yīng)該多學(xué)習(xí)一些，模具的難題是間隙如果配合不 好不但影響工件的尺寸精度而且對(duì)模具的使用壽命還有很大的危害，所以在這方面我還要多 問老師多查找資料，以便提高自己模具方面的專業(yè)知識(shí)。 這次我非常慶幸的戰(zhàn)勝了我自己，說實(shí)在話剛一看到自己的設(shè)計(jì)題目時(shí)，我真是非常的 想往后退縮，不過又一想不還是有指導(dǎo)老師和同學(xué)們的幫助嗎/于是自己強(qiáng)制說服了自己， 投入到了設(shè)計(jì)之中，現(xiàn)在回頭看一下自己曾經(jīng)的位置，心里有一種一覽眾山小的感覺，我知 道自己的付出得到了回報(bào)，我戰(zhàn)勝了自己，我又增加了新的立足社會(huì)的資本。 通過這次的設(shè)計(jì)，我不但學(xué)到了很多知識(shí)，而且我也領(lǐng)悟到了許多做人的大道理，感 謝學(xué)校給的這次機(jī)會(huì)，感謝幫我助我的各位老師和同學(xué)們。 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 27 致謝 伴著晨鐘迎著暮鼓外加幾個(gè)不眠之夜，終于看到了勝利的曙光聽到了成功的歌聲，畢業(yè) 設(shè)計(jì)審核通過定稿了。 回頭曲頸看一看從接到題目到現(xiàn)在成功定稿的這一段路程，我不禁感慨萬千，因?yàn)檫@一 段看似短暫但是走上去坎坷萬千的路，不僅滴滿了我的心血而且還灑滿了我的指導(dǎo)老師和同 學(xué)們的汗水，沒有他們無私的幫助，我就無法揚(yáng)起順利的帆，成功及時(shí)的靠岸，摘去這勝利 的果實(shí)。 張九強(qiáng)老師是我這次畢業(yè)設(shè)計(jì)的指導(dǎo)老師，在我取得這次的成功中起到了不可估量的作 用，他為了我的畢業(yè)設(shè)計(jì)，放下了手頭上的一切事務(wù)，給我提供了大量的幫助，其中的一幕 將會(huì)永遠(yuǎn)留在我的記憶中，時(shí)時(shí)刻刻的感動(dòng)著我，那是一天的下午我去找張老師請(qǐng)教設(shè)計(jì)上 的問題，他不停的為我講解著，時(shí)間在不知不覺一分一秒的過去了，張老師突然猛地一抬頭 記起了他那年齡還尚小的孩子，還在學(xué)校，恰巧那幾天師娘去外地出差了，他充滿歉意的說 讓我先等一下去把小孩接回他的辦公室之后，又開始為我耐心的講解起來，直到七點(diǎn)多鐘了 才算解決完所有問題，而他懂事的孩子卻還一直餓著肚子始終未吭一聲，因師娘不在家，我 想那天晚上張老師肯定很晚才休息。每每到這我的鼻尖都不禁發(fā)酸，眼淚直想往下掉。在這 里我要真誠的說一聲：張老師您辛苦了。 在這次的設(shè)計(jì)中，還有我的同組成員以及其他組的一些同學(xué)和老師也都為我的這次的成 功無私的付出了愛心，在此我一并向他們表示感謝。 “做人不能忘本，做人不能忘恩”我將永遠(yuǎn)記著那些曾經(jīng)在我低谷的時(shí)候拉了我一把的 人，并將他們這種無私的行動(dòng)當(dāng)作愛的接力棒一直傳遞下去。 扶清森 2006.12.25 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 28 參考文獻(xiàn) 1 張超英.沖壓模具與制造.北京：化學(xué)工業(yè)出版社,2003.6 2 羅學(xué)科.模具識(shí)圖與制圖.北京：化學(xué)工業(yè)出版社,2003.6 3 韓洪濤.機(jī)械制造技術(shù).北京：化學(xué)工業(yè)出版社,2003.7 4 萬本善.實(shí)用沖模結(jié)構(gòu)圖解與沖壓新工藝詳圖及常用數(shù)據(jù)速查速用手冊(cè).北京：科大 電子出版社,2004.8 5 李銘杰.沖模設(shè)計(jì)應(yīng)用實(shí)例.北京:機(jī)械工業(yè)出版社,2003.8 6 王立剛.沖模設(shè)計(jì)手冊(cè).北京:機(jī)械工業(yè)出版社,2002.5 7 郭書彬.最新沖壓新工藝新技術(shù)與沖模設(shè)計(jì)圖集及典型疑難實(shí)例應(yīng)用手冊(cè).北京:機(jī)械工業(yè)出版社， 2003.9 8 王芳.冷沖壓模具設(shè)計(jì)指導(dǎo).北京:機(jī)械工業(yè)出版社,1998.10 9 羅德春.沖模設(shè)計(jì)應(yīng)用實(shí)例.北京:機(jī)械出版社,1999.5 10 王秀鳳 萬良輝 .冷沖壓模具設(shè)計(jì)與制造.北京:北京航空航天大學(xué)出版社,2005.4 11 成虹.沖壓工藝與模具設(shè)計(jì).北京:高等教育出版社,2006.7 12 楊玉英.崔令江.實(shí)用沖壓工藝及模具設(shè)計(jì)手冊(cè).北京:機(jī)械工業(yè)出版社,2005.1 13 彭建生.模具設(shè)計(jì)與加工速查手冊(cè).北京:機(jī)械工業(yè)出版社,2005.7 14 徐政坤.沖壓模具及設(shè)備.北京：機(jī)械工業(yè)出版社，2005.1 15 余最康.冷沖壓模具設(shè)計(jì)與制造.南京：江蘇科技出版社，1985.6 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì) 29 濟(jì)源職業(yè)技術(shù)學(xué)院畢業(yè)設(shè)計(jì)（論文）意見表 指導(dǎo)教師意見： 教師簽字： 年 月 日 評(píng)閱人意見： 評(píng)閱人簽字： 年 月 日 答辯委員會(huì)意見： 成 績 評(píng) 定： 答辯組組長簽字： 年 月 Int J Adv Manuf Technol (2002) 19:253259 2002 Springer-Verlag London Limited An Analysis of Draw-Wall Wrinkling in a Stamping Die Design F.-K. Chen and Y.-C. Liao Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan Wrinkling that occurs in the stamping of tapered square cups and stepped rectangular cups is investigated. A common characteristic of these two types of wrinkling is that the wrinkles are found at the draw wall that is relatively unsup- ported. In the stamping of a tapered square cup, the effect of process parameters, such as the die gap and blank-holder force, on the occurrence of wrinkling is examined using finite- element simulations. The simulation results show that the larger the die gap, the more severe is the wrinkling, and such wrinkling cannot be suppressed by increasing the blank-holder force. In the analysis of wrinkling that occurred in the stamping of a stepped rectangular cup, an actual production part that has a similar type of geometry was examined. The wrinkles found at the draw wall are attributed to the unbalanced stretching of the sheet metal between the punch head and the step edge. An optimum die design for the purpose of eliminating the wrinkles is determined using finite-element analysis. The good agreement between the simulation results and those observed in the wrinkle-free production part validates the accuracy of the finite-element analysis, and demonstrates the advantage of using finite-element analysis for stamping die design. Keywords: Draw-wall wrinkle; Stamping die; Stepped rec- tangular cup; Tapered square cups 1. Introduction Wrinkling is one of the major defects that occur in the sheet metal forming process. For both functional and visual reasons, wrinkles are usually not acceptable in a finished part. There are three types of wrinkle which frequently occur in the sheet metal forming process: flange wrinkling, wall wrinkling, and elastic buckling of the undeformed area owing to residual elastic compressive stresses. In the forming operation of stamp- ing a complex shape, draw-wall wrinkling means the occurrence Correspondence and offprint requests to: Professor F.-K. Chen, Depart- ment of Mechanical Engineering, National Taiwan University, No. 1 Roosevelt Road, Sec. 4, Taipei, Taiwan 10617. E-mail: fkchenL50560 w3.me.ntu.edu.tw of wrinkles in the die cavity. Since the sheet metal in the wall area is relatively unsupported by the tool, the elimination of wall wrinkles is more difficult than the suppression of flange wrinkles. It is well known that additional stretching of the material in the unsupported wall area may prevent wrinkling, and this can be achieved in practice by increasing the blank- holder force; but the application of excessive tensile stresses leads to failure by tearing. Hence, the blank-holder force must lie within a narrow range, above that necessary to suppress wrinkles on the one hand, and below that which produces fracture on the other. This narrow range of blank-holder force is difficult to determine. For wrinkles occurring in the central area of a stamped part with a complex shape, a workable range of blank-holder force does not even exist. In order to examine the mechanics of the formation of wrinkles, Yoshida et al. 1 developed a test in which a thin plate was non-uniformly stretched along one of its diagonals. They also proposed an approximate theoretical model in which the onset of wrinkling is due to elastic buckling resulting from the compressive lateral stresses developed in the non-uniform stress field. Yu et al. 2,3 investigated the wrinkling problem both experimentally and analytically. They found that wrinkling could occur having two circumferential waves according to their theoretical analysis, whereas the experimental results indi- cated four to six wrinkles. Narayanasamy and Sowerby 4 examined the wrinkling of sheet metal when drawing it through a conical die using flat-bottomed and hemispherical-ended punches. They also attempted to rank the properties that appeared to suppress wrinkling. These efforts are focused on the wrinkling problems associa- ted with the forming operations of simple shapes only, such as a circular cup. In the early 1990s, the successful application of the 3D dynamic/explicit finite-element method to the sheet- metal forming process made it possible to analyse the wrinkling problem involved in stamping complex shapes. In the present study, the 3D finite-element method was employed to analyse the effects of the process parameters on the metal flow causing wrinkles at the draw wall in the stamping of a tapered square cup, and of a stepped rectangular part. A tapered square cup, as shown in Fig. 1(a), has an inclined draw wall on each side of the cup, similar to that existing in a conical cup. During the stamping process, the sheet metal on the draw wall is relatively unsupported, and is therefore 254 F.-K. Chen and Y.-C. Liao Fig. 1. Sketches of (a) a tapered square cup and (b) a stepped rectangular cup. prone to wrinkling. In the present study, the effect of various process parameters on the wrinkling was investigated. In the case of a stepped rectangular part, as shown in Fig. 1(b), another type of wrinkling is observed. In order to estimate the effectiveness of the analysis, an actual production part with stepped geometry was examined in the present study. The cause of the wrinkling was determined using finite-element analysis, and an optimum die design was proposed to eliminate the wrinkles. The die design obtained from finite-element analy- sis was validated by observations on an actual production part. 2. Finite-Element Model The tooling geometry, including the punch, die and blank- holder, were designed using the CAD program PRO/ ENGINEER. Both the 3-node and 4-node shell elements were adopted to generate the mesh systems for the above tooling using the same CAD program. For the finite-element simul- ation, the tooling is considered to be rigid, and the correspond- ing meshes are used only to define the tooling geometry and Fig. 2. Finite-element mesh. are not for stress analysis. The same CAD program using 4- node shell elements was employed to construct the mesh system for the sheet blank. Figure 2 shows the mesh system for the complete set of tooling and the sheet-blank used in the stamping of a tapered square cup. Owing to the symmetric conditions, only a quarter of the square cup is analysed. In the simulation, the sheet blank is put on the blank-holder and the die is moved down to clamp the sheet blank against the blank-holder. The punch is then moved up to draw the sheet metal into the die cavity. In order to perform an accurate finite-element analysis, the actual stressstrain relationship of the sheet metal is required as part of the input data. In the present study, sheet metal with deep-drawing quality is used in the simulations. A tensile test has been conducted for the specimens cut along planes coinciding with the rolling direction (0) and at angles of 45 and 90 to the rolling direction. The average flow stress H9268, calculated from the equation H9268H11005(H9268 0 H11001 2H9268 45 H11001H9268 90 )/4, for each measured true strain, as shown in Fig. 3, is used for the simulations for the stampings of the tapered square cup and also for the stepped rectangular cup. All the simulations performed in the present study were run on an SGI Indigo 2 workstation using the finite-element pro- gram PAMFSTAMP. To complete the set of input data required Fig. 3. The stressstrain relationship for the sheet metal. Draw-Wall Wrinkling in a Stamping Die Design 255 for the simulations, the punch speed is set to 10 m s H110021 and a coefficient of Coulomb friction equal to 0.1 is assumed. 3. Wrinkling in a Tapered Square Cup A sketch indicating some relevant dimensions of the tapered square cup is shown in Fig. 1(a). As seen in Fig. 1(a), the length of each side of the square punch head (2W p ), the die cavity opening (2W d ), and the drawing height (H) are con- sidered as the crucial dimensions that affect the wrinkling. Half of the difference between the dimensions of the die cavity opening and the punch head is termed the die gap (G) in the present study, i.e. G H11005 W d H11002 W p . The extent of the relatively unsupported sheet metal at the draw wall is presumably due to the die gap, and the wrinkles are supposed to be suppressed by increasing the blank-holder force. The effects of both the die gap and the blank-holder force in relation to the occurrence of wrinkling in the stamping of a tapered square cup are investigated in the following sections. 3.1 Effect of Die Gap In order to examine the effect of die gap on the wrinkling, the stamping of a tapered square cup with three different die gaps of 20 mm, 30 mm, and 50 mm was simulated. In each simulation, the die cavity opening is fixed at 200 mm, and the cup is drawn to the same height of 100 mm. The sheet metal used in all three simulations is a 380 mm H11003 380 mm square sheet with thickness of 0.7 mm, the stressstrain curve for the material is shown in Fig. 3. The simulation results show that wrinkling occurred in all three tapered square cups, and the simulated shape of the drawn cup for a die gap of 50 mm is shown in Fig. 4. It is seen in Fig. 4 that the wrinkling is distributed on the draw wall and is particularly obvious at the corner between adjacent walls. It is suggested that the wrinkling is due to the large unsupported area at the draw wall during the stamping process, also, the side length of the punch head and the die cavity Fig. 4. Wrinkling in a tapered square cup (G H11005 50 mm). opening are different owing to the die gap. The sheet metal stretched between the punch head and the die cavity shoulder becomes unstable owing to the presence of compressive trans- verse stresses. The unconstrained stretching of the sheet metal under compression seems to be the main cause for the wrink- ling at the draw wall. In order to compare the results for the three different die gaps, the ratio H9252 of the two principal strains is introduced, H9252 being H9280 min /H9280 max , where H9280 max and H9280 min are the major and the minor principal strains, respectively. Hosford and Caddell 5 have shown that if the absolute value of H9252 is greater than a critical value, wrinkling is supposed to occur, and the larger the absolute value of H9252, the greater is the possibility of wrinkling. The H9252 values along the cross-section MN at the same drawing height for the three simulated shapes with different die gaps, as marked in Fig. 4, are plotted in Fig. 5. It is noted from Fig. 5 that severe wrinkles are located close to the corner and fewer wrinkles occur in the middle of the draw wall for all three different die gaps. It is also noted that the bigger the die gap, the larger is the absolute value of H9252. Consequently, increasing the die gap will increase the possibility of wrinkling occurring at the draw wall of the tapered square cup. 3.2 Effect of the Blank-Holder Force It is well known that increasing the blank-holder force can help to eliminate wrinkling in the stamping process. In order to study the effectiveness of increased blank-holder force, the stamping of a tapered square cup with die gap of 50 mm, which is associated with severe wrinkling as stated above, was simulated with different values of blank-holder force. The blank-holder force was increased from 100 kN to 600 kN, which yielded a blank-holder pressure of 0.33 MPa and 1.98 MPa, respectively. The remaining simulation conditions are maintained the same as those specified in the previous section. An intermediate blank-holder force of 300 kN was also used in the simulation. The simulation results show that an increase in the blank- holder force does not help to eliminate the wrinkling that occurs at the draw wall. The H9252 values along the cross-section Fig. 5. H9252-value along the cross-section MN for different die gaps. 256 F.-K. Chen and Y.-C. Liao MN, as marked in Fig. 4, are compared with one another for the stamping processes with blank-holder force of 100 kN and 600 kN. The simulation results indicate that the H9252 values along the cross-section MN are almost identical in both cases. In order to examine the difference of the wrinkle shape for the two different blank-holder forces, five cross-sections of the draw wall at different heights from the bottom to the line M N, as marked in Fig. 4, are plotted in Fig. 6 for both cases. It is noted from Fig. 6 that the waviness of the cross-sections for both cases is similar. This indicates that the blank-holder force does not affect the occurrence of wrinkling in the stamp- ing of a tapered square cup, because the formation of wrinkles is mainly due to the large unsupported area at the draw wall where large compressive transverse stresses exist. The blank- holder force has no influence on the instability mode of the material between the punch head and the die cavity shoulder. 4. Stepped Rectangular Cup In the stamping of a stepped rectangular cup, wrinkling occurs at the draw wall even though the die gaps are not so significant. Figure 1(b) shows a sketch of a punch shape used for stamping a stepped rectangular cup in which the draw wall C is followed by a step DE. An actual production part that has this type of geometry was examined in the present study. The material used for this production part was 0.7 mm thick, and the stress strain relation obtained from tensile tests is shown in Fig. 3. The procedure in the press shop for the production of this stamping part consists of deep drawing followed by trimming. In the deep drawing process, no draw bead is employed on the die surface to facilitate the metal flow. However, owing to the small punch corner radius and complex geometry, a split occurred at the top edge of the punch and wrinkles were found to occur at the draw wall of the actual production part, as shown in Fig. 7. It is seen from Fig. 7 that wrinkles are distributed on the draw wall, but are more severe at the corner edges of the step, as marked by AD and BE in Fig. 1(b). The metal is torn apart along the whole top edge of the punch, as shown in Fig. 7, to form a split. In order to provide a further understanding of the defor- mation of the sheet-blank during the stamping process, a finite- element analysis was conducted. The finite-element simulation was first performed for the original design. The simulated shape of the part is shown from Fig. 8. It is noted from Fig. 8 that the mesh at the top edge of the part is stretched Fig. 6. Cross-section lines at different heights of the draw wall for different blank-holder forces. (a) 100 kN. (b) 600 kN. Fig. 7. Split and wrinkles in the production part. Fig. 8. Simulated shape for the production part with split and wrinkles. significantly, and that wrinkles are distributed at the draw wall, similar to those observed in the actual part. The small punch radius, such as the radius along the edge AB, and the radius of the punch corner A, as marked in Fig. 1(b), are considered to be the major reasons for the wall breakage. However, according to the results of the finite- element analysis, splitting can be avoided by increasing the above-mentioned radii. This concept was validated by the actual production part manufactured with larger corner radii. Several attempts were also made to eliminate the wrinkling. First, the blank-holder force was increased to twice the original value. However, just as for the results obtained in the previous section for the drawing of tapered square cup, the effect of blank-holder force on the elimination of wrinkling was not found to be significant. The same results are also obtained by increasing the friction or increasing the blank size. We conclude that this kind of wrinkling cannot be suppressed by increasing the stretching force. Since wrinkles are formed because of excessive metal flow in certain regions, where the sheet is subjected to large com- pressive stresses, a straightforward method of eliminating the wrinkles is to add drawbars in the wrinkled area to absorb the redundant material. The drawbars should be added parallel to the direction of the wrinkles so that the redundant metal can be absorbed effectively. Based on this concept, two drawbars are added to the adjacent walls, as shown in Fig. 9, to absorb the excessive material. The simulation results show that the Draw-Wall Wrinkling in a Stamping Die Design 257 Fig. 9. Drawbars added to the draw walls. wrinkles at the corner of the step are absorbed by the drawbars as expected, however some wrinkles still appear at the remain- ing wall. This indicates the need to put more drawbars at the draw wall to absorb all the excess material. This is, however, not permissible from considerations of the part design. One of the advantages of using finite-element analysis for the stamping process is that the deformed shape of the sheet blank can be monitored throughout the stamping process, which is not possible in the actual production process. A close look at the metal flow during the stamping process reveals that the sheet blank is first drawn into the die cavity by the punch head and the wrinkles are not formed until the sheet blank touches the step edge DE marked in Fig. 1(b). The wrinkled shape is shown in Fig. 10. This provides valuable information for a possible modification of die design. An initial surmise for the cause of the occurrence of wrink- ling is the uneven stretch of the sheet metal between the punch corner radius A and the step corner radius D, as indicated in Fig. 1(b). Therefore a modification of die design was carried out in which the step corner was cut off, as shown in Fig. 11, so that the stretch condition is changed favourably, which allows more stretch to be applied by increasing the step edges. However, wrinkles were still found at the draw wall of the cup. This result implies that wrinkles are introduced because of the uneven stretch between the whole punch head edge and the whole step edge, not merely between the punch corner and Fig. 10. Wrinkle formed when the sheet blank touches the stepped edge. Fig. 11. Cut-off of the stepped corner. the step corner. In order to verify this idea, two modifications of the die design were suggested: one is to cut the whole step off, and the other is to add one more drawing operation, that is, to draw the desired shape using two drawing operations. The simulated shape for the former method is shown in Fig. 12. Since the lower step is cut off, the drawing process is quite similar to that of a rectangular cup drawing, as shown in Fig. 12. It is seen in Fig. 12 that the wrinkles were eliminated. In the two-operation drawing process, the sheet blank was first drawn to the deeper step, as shown in Fig. 13(a). Sub- sequently, the lower step was formed in the second drawing operation, and the desired shape was then obtained, as shown in Fig. 13(b). It is seen clearly in Fig. 13(b) that the stepped rectangular cup can be manufactured without wrinkling, by a two-operation drawing process. It should also be noted that in the two-operation drawing process, if an opposite sequence is applied, that is, the lower step is formed first and is followed by the drawing of the deeper step, the edge of the deeper step, as shown by AB in Fig. 1(b), is prone to tearing because the metal cannot easily flow over the lower step into the die cavity. The finite-element simulations have indicated that the die design for stamping the desired stepped rectangular cup using one single draw operation is barely achieved. However, the manufacturing cost is expected to be much higher for the two- operation drawing process owing to the additional die cost and operation cost. In order to maintain a lower manufacturing cost, the part design engineer made suitable shape changes, and modified the die design according to the finite-element Fig. 12.