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弯曲 冲压 工艺 模具设计 说明书 CAD

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凹型弯曲件的冲压工艺及模具设计【说明书+CAD】,弯曲,冲压,工艺,模具设计,说明书,CAD

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河南机电高等专科学校学生毕业设计（论文）中期检查表学生姓名王桂周学 号0412226指导教师于智宏选题情况课题名称型弯曲件的冲压工艺及模具设计难易程度偏难适中偏易工作量较大合理较小符合规范化的要求任务书有无开题报告有无外文翻译质量优良中差学习态度、出勤情况好一般差工作进度快按计划进行慢中期工作汇报及解答问题情况优良中差中期成绩评定：所在专业意见： 负责人： 2007 年 04月 20日河南机电高等专科学校毕业设计说明书 河南机电高等专科学校毕业设计（论文）任务书系 部： 材料工程系 专 业： 模具设计与制造 学生姓名: 王桂周 学 号: 0412226 设计(论文)题目： 型弯曲件的冲压工艺及模具设计 起 迄 日 期: 2007 年 3月 22 日 5月 22 日 指 导 教 师: 王强 于智宏 2007 年 3月 20 日 绪 论 目前，我国冲压技术与工业发达国家相比还相当的落后，主要原因是我国在冲压基础理论及成形工艺、模具标准化、模具设计、模具制造工艺及设备等方面与工业发达的国家尚有相当大的差距，导致我国模具在寿命、效率、加工精度、生产周期等方面与工业发达国家的模具相比距离相当大。一、 国内模具的现状和发展趋势(1)国内模具的现状 我国模具近年来发展很快，据不完全统计，2003年我国模具生产厂家约有2万多家，从业人员约50多万人，2004年模具行业的发展保持良好势头，模具企业总体上订单充足，任务饱满，2004年模具产值530亿元。进口模具18.13亿美元，出口模具4.91亿美元，分别比2003年增长18%、32.4%和45.9%。进出口之比2004年为3.69:1，进出口相抵后的进净口达13.2亿美元，为净进口量较大的国家。在2万多家生产厂点中，有一半以上是自产自用的。在模具企业中，产值过亿元的模具企业只有20多家，中型企业几十家，其余都是小型企业。近年来，模具行业结构调整和体制改革步伐加快，主要表现为：大型、精密、复杂、长寿命中高档模具及模具标准件发展速度快于一般模具产品；专业模具厂数量增加，能力提高较快；三资及私营企业发展迅速；国企股份制改造步伐加快等。虽然说我国模具业发展迅速，但远远不能适应国民经济发展的需要。我国尚存在以下几方面的不足: 第一，体制不顺，基础薄弱。 “三资”企业虽然已经对中国模具工业的发展起了积极的推动作用，私营企业近年来发展较快，国企改革也在进行之中，但总体来看，体制和机制尚不适应市场经济，再加上国内模具工业基础薄弱，因此，行业发展还不尽如人意，特别是总体水平和高新技术方面。 第二，开发能力较差，经济效益欠佳.我国模具企业技术人员比例低，水平较低，且不重视产品开发，在市场中经常处于被动地位。我国每个模具职工平均年创造产值约合1万美元，国外模具工业发达国家大多是1520万美元，有的高达2530万美元，与之相对的是我国相当一部分模具企业还沿用过去作坊式管理，真正实现现代化企业管理的企业较少。 第三，工艺装备水平低，且配套性不好，利用率低虽然国内许多企业采用了先进的加工设备，但总的来看装备水平仍比国外企业落后许多，特别是设备数控化率和CAD/CAM应用覆盖率要比国外企业低得多。由于体制和资金等原因，引进设备不配套，设备与附配件不配套现象十分普遍，设备利用率低的问题长期得不到较好解决。装备水平低，带来中国模具企业钳工比例过高等问题。 第四，专业化、标准化、商品化的程度低、协作差 由于长期以来受“大而全”“小而全”影响，许多模具企业观念落后，模具企业专业化生产水平低，专业化分工不细，商品化程度也低。目前国内每年生产的模具，商品模具只占45%左右，其馀为自产自用。模具企业之间协作不好，难以完成较大规模的模具成套任务，与国际水平相比要落后许多。模具标准化水平低，标准件使用覆盖率低也对模具质量、成本有较大影响，对模具制造周期影响尤甚。 第五，模具材料及模具相关技术落后模具材料性能、质量和品种往往会影响模具质量、寿命及成本，国产模具钢与国外进口钢相比，无论是质量还是品种规格，都有较大差距。塑料、板材、设备等性能差，也直接影响模具水平的提高。(2)国内模具的发展趋势 巨大的市场需求将推动中国模具的工业调整发展。虽然我国的模具工业和技术在过去的十多年得到了快速发展，但与国外工业发达国家相比仍存在较大差距，尚不能完全满足国民经济高速发展的需求。未来的十年，中国模具工业和技术的主要发展方向包括以下几方面: 1） 模具日趋大型化； 2）在模具设计制造中广泛应用CAD/CAE/CAM技术； 3）模具扫描及数字化系统； 4）提高模具标准化水平和模具标准件的使用率； 5）发展优质模具材料和先进的表面处理技术； 6）模具的精度将越来越高； 7）模具研磨抛光将自动化、智能化； 8）研究和应用模具的高速测量技术与逆向工程；9）开发新的成形工艺和模具。二、国外模具的现状和发展趋势模具是工业生产关键的工艺装备，在电子、建材、汽车、电机、电器、仪器仪表、家电和通讯器材等产品中，6080的零部件都要依靠模具成型。用模具生产制作表现出的高效率、低成本、高精度、高一致性和清洁环保的特性，是其他加工制造方法所无法替代的。模具生产技术水平的高低，已成为衡量一个国家制造业水平高低的重要标志，并在很大程度上决定着产品的质量、效益和新产品的开发能力。近几年，全球模具市场呈现供不应求的局面，世界模具市场年交易总额为600650亿美元左右。美国、日本、法国、瑞士等国家年出口模具量约占本国模具年总产值的三分之一。国外模具总量中,大型、精密、复杂、长寿命模具的比例占到50%以上；国外模具企业的组织形式是大而专、大而精。2004年中国模协在德国访问时，从德国工、模具行业组织-德国机械制造商联合会（VDMA）工模具协会了解到，德国有模具企业约5000家。2003年德国模具产值达48亿欧元。其中（VDMA）会员模具企业有90家，这90家骨干模具企业的产值就占德国模具产值的90%，可见其规模效益。 随着时代的进步和技术的发展，国外的一些掌握和能运用新技术的人才如模具结构设计、模具工艺设计、高级钳工及企业管理人才，他们的技术水平比较高故人均产值也较高我国每个职工平均每年创造模具产值约合1万美元左右，而国外模具工业发达国家大多1520万美元，有的达到 2530万美元。国外先进国家模具标准件使用覆盖率达70%以上，而我国才达到45第一章 弯曲件工艺分析1.1 弯曲件工艺性分析工件名称：型弯曲件工件简图：如图所示生产批量：大批量材料：08钢材料厚度：2 mm图1制件图由上图可知,此工件为典型型弯曲件。材料为08钢，具有良好的弯曲性能适合弯曲成型加工。工件结构简单，除了装配尺寸，公差等级IT14级有严格要求外其余尺寸均为自由公差，工件整体上看，尺寸精度较高，普通弯曲成型不能完全满足要求,需要复合弯曲。1.2 弯曲件研究思路 本课题研究的思路: 型弯曲件模具的设计. 型弯曲件是最典型的弯曲件，其工作过程很简单就一个弯曲，根据实际确定它不能一次弯曲成功.因此，需要两次弯曲。从制件的成型原理和模具加工成本考虑，确定此次弯曲不采用标准的模架。为了保证制件的顺利加工，模具必须有足够精度。要保证模具的精度，特别要保证导柱和导套的配合精度,保证导柱和导套的配合精度的同时,还要注意保证导柱和导套的刚度. 另外，模具的精度还和弯曲凸模与弯曲凹模工作配合精度有关设计时可能精度出现误差，应当边试冲边修改调整。只有加强弯曲变形基础理论的研究，才能提供更加准确、实用、方便的计算方法，才能正确地确定弯曲工艺参数和模具工作部分的几何形状与尺寸，解决弯曲变形中出现的各种实际问题，从而，进一步提高制件质量。 本课题设计进度的安排如下：1.了解目前国内外冲压模具的发展现状，所用时间15天；2.确定加工方案，所用时间5天；3.模具的设计，所用时间30天； 4.模具的调试所用时间5天。第二章 弯曲工艺方案的确定2.1 方案介绍 该工件弯曲成型，可以一次弯曲成型，也可以二次弯曲成型如今有以下三种方案供选择：方案一：采用一次弯曲成型，单工序生产。如下图所示： 图2方案二：采用两次弯曲成型，先弯U型，再弯型，采用两套单工序模生产具体如下图所示：图a 为首次弯曲模具结构图；图b为第二次弯曲模具结构图。 a)首次弯曲 b)二次弯曲图3方案三：采用在一套模具上成型，复合模生产。 具体如下图所示：图42.2 方案分析：方案一、模具结构简单，生产制造成本低，但工件尺寸精度低，尤其是四个直角的精度难以得到保证。另外，在弯曲过程中，由于凸模肩部妨碍了坯料的转动，加大了坯料通过凹模圆角的摩擦力，使弯曲件侧壁容易擦伤和变薄，成型后弯曲件两肩部与底面不平行。方案二、模具结构相对简单，生产成本较高，由于采用两副模具进行弯曲成形，从而可以避免了方案一中的缺陷，提高了弯曲件的质量，但由于采用两副模具进行生产，生产效率低，另外，凹模的强度不易保证。方案三、模具结构复杂，生产制造成本与方案二差不多，但是工件尺寸精度，位置精度容易保证，生产效率也高。综上所述，经过对三种方案的比较分析可见，该工件的弯曲成型生产采用方案三比较合理。第三章 设计计算3.1 主要设计计算3.1.1 弯曲件毛坯坯料尺寸的计算 L= 式中: L弯曲件毛坯长度（mm）; 弯曲件各直线段长度之和（mm）; 弯曲件各部分（圆弧部分）应变中性层展开长度之和（mm）;图5 由图可知：L=2+2+4 式中： 第一段圆弧部分应变中性层展开长度（mm）; 其中： =（85-54）/2-t-r =（80-54）/2-2-1 =10 mm =22-2（t+ r） =22-2（2+1） =16 mm =54-2 r =54-2 =52 查模具设计大典3得公式：=1.57式中：应变中性层的曲率半径（mm）；其中：= r+X t式中：X中性层位移系数，查冲压模具设计与制造教程，表3.4.1得X=0.25；所以：=1+0.25 X 2 =1.5 mm所以：=1.57 X 1.5 =2.355 mm 毛坯长度：L=2 X 10+2 X 16+52+4 X 2.36 =113.42 mm3.1.2 弯曲应力的计算该模具工件属于自由弯曲成型，所以U形件弯曲力： = 式中：自由弯曲在冲压行程结束时的弯曲力(N); B弯曲件的宽度,B=70 mm; t 弯曲材料的厚度(mm); r 弯曲件的内弯曲半径(mm); 材料的抗拉强度(MPa); K安全系数,一般取K=1.3。 = 32444.53 N3.1.3 压料力的计算根据公式(3.5.4),如果弯曲模设有顶出装置或压料装置时,其顶出力可以近似取自由弯曲力的30% 80%即: =(0.3 0.8) 在此取: =0.6 =0.6 X32444.53 =1946.72 N3.1.4 压力机公称压力的确定根据公式(3.5.5)即: (1.2 1.3) (+)式中: _弯曲应力 _压料力考虑到弯曲工件板料较厚,而且板宽也较大,压力机公称压力应取值偏大为宜。在此取: 1.3(+) =1.3 X (32444.53+1946.72) =44708.63 N根据计算结果,查表2-3初选压力机为：J23-10。3.2 弯曲模工作部分尺寸的设计 由方案三可知,所设计的复合模整个工作原理可分为两部分: U型弯曲和在U 型弯曲基础上的型弯曲。归根到底,其设计为U 型弯曲种类,所以,其设计可按U 型件设计方法设计因为=0.5, 值较小,所以取=r=1 mm3.2.2 凹模圆角半径根据实际生产经验可知: 当t = 2 4 mm 时, =(2 3) t从保证制件精度要求考虑,特别是所设计的弯曲复合模值不宜取大值。在此取：2 t2 X 24 mm 。3.2.3 凹模深度 图6 凹模深度过小,则坯料两端受压部分太多,工件回弹大,而且不平直,影响工件质量。如果过大,则浪费模具钢材,且需冲床有较大的工作行程。由前面计算可知弯曲件边长L=+ =10+16+2.36 =28.36 mm据边长L=28.36 mm 查表19.3-18得: = 20 mm3.2.4 凹凸模间隙计算查的U 型件弯曲的凸凹模单边间隙可按下式计算: C = + x t = t + + x t 式中: C弯曲凹、凸模单边间隙(mm); t工件材料厚度(基本尺寸) (mm); 工件材料厚度的正偏差(mm); X间隙系数,查表19.3-19得 X = 0.1 ; 所以: C = 2 + 0.006 + 0.1 x 2 =2.206 mm3.3 U 形弯曲凸凹模横向尺寸的设计 图7由工件图上可知:工件是内形标注的弯曲件,设计时应该以凸模为基准先确定凹模尺寸。再利用凸凹间隙求出凹模的尺寸。根据教程公式(3.944)与(3.9.5)得: 凸模尺寸为: = ( + 0.75 式中: 凸模横向尺寸(mm); 弯曲件横向的最小极限尺寸(mm); 弯曲件的尺寸公差(mm); 凸模的制造公差,采用IT7级。 所以: =(54 + 0.75 x 0.74 =54.56查表1-6标准公差数值IT7级得: =54056 mm凹模尺寸为: =( + Z 式中: 凹模横向尺寸(mm); Z凹凸模双面间隙(mm); 凹模的制造公差,取IT8级得: = (54.56 + 4.412 = 58.972查表1-6标准公差值IT 8级得: = 58.9723.4 弹簧的选用 弹簧是模具中广泛应用的弹性元件,主要为弹性卸料用.3.4.1每个弹簧力计算 根据模具安装位置,选定4个弹簧,每个弹簧的弹顶力为: / N 式中: 弹簧复位的弹顶力(N),在此=44708.63 N ; 弹簧的预顶力(N); N弹簧数量。 / N = 44708.63/4 = 11177.19 N) 查 GB/T2089-94表有关弹簧规格,初选规格为35 mm x 10 mm x 300 mm,具体参数是D=35 mm , d = 10 mm , t =21.7 mm = 27806 N , = 125 mm , = 300 mm , n = 12.5。3.4.2弹簧预压缩量 = 式中: 弹簧预压缩量(mm); 弹簧最大允许负荷(N)。 所以: = x 125 =50.23 mm3.4.3 弹簧校核弹簧实际工作总压缩量: = + 式中: 弹簧工作行程 (mm); = + 式中: 凸模进入凹模深度22 mm ; 摆块进行二次弯曲工作时,凸模下滑行程50 mm 。 所以: = 22 + 50 = 72 mm = + = 50.23 + 72 = 122.23 mm 显然, + 由前面弯曲件坯料尺寸计算可知, = 10 mm , = 2.355 mm 。 所以: 10 + 2.355 =12.355 mm综合考虑模具刚度和生产成本,在此取 = 14 mm 。 所以: L = 58.972 + 2 x 14 = 86.976 mm 在此,取L = 87 mm 。 高度方向: = + 式中: 首次弯曲凸模进入凹模的深度 = 22 mm ； 压板高度（mm），= 23 mm 。所以： = 22 + 23 = 45 mm凹模其余尺寸的设计和凹模结构的具体设计可参见后面的凹模结构零件图所示。5.3 摆块的结构的设计5.3.1 摆块的结构草图如下所示：图11摆块草图5.3.2 摆块的主要尺寸的设计圆角半径R：R = / 2 式中： 摆块的厚度（mm），根据摆块的工作受力情况和生产成本考虑在此选 = 16 mm 。 所以：R = 16 / 2 = 8 mm摆块宽度B：B = = 70 mm 式中： 弯曲坯料的板宽70 mm。摆块的工作原理图如下所示：图12摆块工作原理 由上面摆块工作原理得L的计算公式如下： L = + + 式中： 模侧壁的厚度，= 14 mm； 坯料厚度，= 2 mm； 摆块厚度，= 16 mm。 L = 14 + 2 + 16 / 2 =24 mm摆块的其余尺寸设计与及具体结构可参见后面摆块零件图所示。5.4 定位零件的设计坯料的定位采用限位钉前方定位和定位块左右定位，限位钉与凸模顶孔采用H7 / n6配合固定,定位块采用销钉定位,螺杆固定在下模座上。5.4.1 限位钉的设计限位钉的结构草图如下所示:图13限位螺钉结构草图由于限位钉只起限位作用,基本上不受过大的力作用,所以限位钉尺寸设计如下即可满足使用要求: = 5 mm D = 8 mm h = 5 mm其余尺寸设计见后面限位钉零件图所示。5.5 定位块的设计 定位块的结构草图如下所示:图14定位块结构草图定位块主要工作尺寸H可按以下公式计算: H = + t + 式中: H 定位块主要工作尺寸(mm); 凹模高度, = 114 mm ; t 坯料厚度, t = 2 mm ; 为定位可靠,设定的自由高度,在此选定= 5 mm。 所以: H = 114 + 2 + 5 =121 mm定位块的其余尺寸设计及具体结构可参见后面定位块零件图所示。5.6 弹顶部件的设计由于工件弯曲受力较大，在此采用弹簧作弹性元件。弹簧具有弹压力大，弹顶灵活等优点。该模具采用4根弹簧，上下垫板和4螺杆组成弹顶部件。5.6.1 垫板的设计由模具结构所限，上下垫板均是圆形结构，主要设计如下：上垫板： 直径115 mm ,厚度12 mm ；下垫板： 直径115 mm ,厚度12 mm ；上下垫板均采用45钢制造，淬火硬度40 45 HRC 。其具体结构见后面垫板零件图所示。5.6.2 导板的设计导板主要起导向定位作用，选用材料T8A，淬火硬度58 60 HRC。制造尺寸：143 mm x 115 mm x 8 mm 。其具体结构以及尺寸设计见后面垫板零件图所示。第六章 压力机的参数与较核 由前面压力机公称压力计算初选的压力机型号：J23-10，查模具实用技术手册表2-3得压力机主要技术参数如下：公称压力：100 KN ；滑块行程：45 mm ；最大闭合高度：180 mm ；最大装模高度：180 mm ；连杆调节长度：35 mm ；工作台尺寸（前后x左右）：130 mm x 200 mm ；垫板尺寸（厚度）：35 mm ；模柄孔尺寸：30 mm x 60 mm ；最大倾斜角度： 由上述技术参数可知，所选压力机J23-10型号可用。第七章 模具零件的加工工艺 7.1 凸模的加工工艺过程表1凸模加工工艺卡工序号工序名称工序内容1备料锯床下料80 mm x 130 mm 2煅造煅成94 mm x 58 mm x 120 mm3热处理退火，硬度 229 HBS4刨刨六面，互为直角92 mm x 58 mm x 120 mm5平磨磨六方91 mm x 55 mm x 115 mm 6数控铣铣出摆块安装槽7热处理淬火硬度58 60 HRC8磨1、 磨外形至图纸要求尺寸，90 mm x 54 mm x 114 mm 。2、 磨安装槽至图纸要求尺寸，70 mm x 16 mm x 84 mm 。9钳1、 倒角去毛刺。2、 画线、钻孔、攻螺纹、精修等。3、 研磨销孔。4、 精修全部达设计要求。7.2 凹模的加工工艺过程表2凹模加工工艺卡工序号工序名称工序内容1下料锯床下料85 mm x 120 mm 2锻造煅成90 mm x 82 mm x 92 mm 3热处理退火,硬度退火，硬度229 HBS4刨刨外形与凹模腔，留2 mm 余量。5磨磨外形与凹模腔，留0.5 mm 余量。6铣树控铣，铣20孔与16孔，留0.5余量。7热处理淬火硬度58 60 HRC8磨磨至图纸要求9钳倒角、去毛刺、精修、研磨凹模腔，16孔。第八章 模具的装配模具的装配全过程如下表格所示：表3装配工序卡序号工序工艺说明1凸凹模预配1、 装配前仔细检查凸模形状、尺寸以及凹模的形状与尺寸，是否符合图纸要求尺寸精度，形状精度。2、 将凸模与凹模相配，检查加工是否均匀。不适合者，应重新修磨或者更换。2凸模装配以凸模为基准，安装好限位钉，摆块。3装配下模1、 把导板与下模座安装好。2、 把弹顶部件安装到下模座上。3、 安装凸模，由上端把已经安装好的凸模部件压入导板孔至上垫板接触，用螺钉把凸模与上垫板连接拧紧。4、 安装定位块，把定位块安装到下模座上。4上模安装把压杆插入凹模后与压板连接好，拧紧。5安装模具分别把上模部分，下模部分安装到压力机工作台上，并调出合理的间隙。6试冲与调整开机试冲并根据试冲的结果作出相应的调整。第九章 模具试冲下表分别列出了模具在试冲时常见的故障，原因和调整方法：表4模具在试冲时常见的故障，原因和调整方法常见故障产生原因调整方法弯曲角度不够1、 凸凹模的回弹角制造过小2、 凸模进入凹模的深度太浅3、 凸、凹模间隙过大4、 试模材料不对5、 弹顶器的弹力太小1、 加大回弹角2、 调整冲模闭合高度3、 调整间隙值4、 更换试冲材料5、 加大弹顶器的弹顶力弯曲位置偏移1、 定位块的位置不对2、 凹模两侧进口圆角大小不等，材料滑动不一致3、 没有压料装置或者压料装置的压力不足和压板位置过低4、 凸模没有对正凹模1、 调整定位板位移2、 修磨凹模圆角3、 加大压料力4、 调整凸凹模位置冲件的尺寸过长或者不足1、 凸凹模之间的间隙过小，材料被拉长2、 压料装置压力过大，将材料拉长3、 设计时计算错误或不正确1、 调整凸凹模间隙2、 减小压料力3、 改变坯料尺寸冲件外部有光亮的凹陷1、 凹模的圆角半径过小，冲件表面被划痕2、 凸、凹模之间的间隙不均匀3、 凸、凹模表面粗糙度太大1、 加大圆角半径2、 调整凸、凹模间隙3、 抛光凸、凹模表面设计总结通过冲压课程设计，我进一步巩固了冲裁理论知识。并且也加深了相关理论知识的认识。同时熟练掌握了专业工具书的使用方法。在整个过程中，增强了自己的动手能力及独立思考解决问题的能力。当然，由于本人水平有限及缺乏生产实际经验，该设计难免存在不足之处。希望老师对此提出批评意见，在此表示万分的感谢。致谢毕业设计是我们进行完了三年的模具设计与制造专业课程后进行的，它是对我们三年来所学课程的又一次深入、系统的综合性的复习，也是一次理论联系实践的训练。它在我们的学习中占有重要的地位。通过这次毕业设计使我在温习学过的知识的同时又学习了许多新知识，对一些原来一知半解的理论也有了进一步的的认识。特别是原来所学的一些专业基础课：如机械制图、模具材料、公差配合与技术测量、冷冲模具设计与制造等有了更深刻的理解，使我进一步的了解了怎样将这些知识运用到实际的设计中。同时还使我更清楚了模具设计过程中要考虑的问题，如怎样使制造的模具既能满足使用要求又不浪费材料，保证工件的经济性，加工工艺的合理性。在学校中，我们主要学的是理论性的知识，而实践性很欠缺，而毕业设计就相当于实战前的一次演练。通过毕业设计可是把我们以前学的专业知识系统的连贯起来，使我们在温习旧知识的同时也可以学习到很多新的知识；这不但提高了我们解决问题的能力，开阔了我们的视野，在一定程度上弥补我们实践经验的不足，为以后的工作打下坚实的基础。通过对弯曲冷冲模的设计，我对冲裁模、弯曲模有了更为深刻的认识，特别是这种弯曲模具的设计。弯曲模的主要零件的加工一般比较复杂，多采用线切割进行加工，弯曲回弹的影响因素多，不容易从纯理论的角度精确的计算出来，多需要在试模后再进行调整。在模具的设计过程中也遇到了一些难以处理的问题，虽然设计中对它们做出了解决 ，但还是感觉这些方案中还是不能尽如人意，如压力计算时的公式的选用、凸凹模间隙的计算、卸件机构选用、工作零件距离的调整，都可以进行进一步的完善，使生产效率提高。参考文献1 刘建超，张宝忠主编.冲压模具设计与制造.北京：高等出版社，2004.62 中国模具设计大典编委员会.中国模具设计大典3.南昌：江西科学出版社，2003.13 任嘉卉主编.公差与配合手册. 北京：机械出版社，2000.44 冯炳光主编.模具设计与制造简明手册.上海：上海科学技术出版社，1998.55 中国标准出版社，全国弹簧标准化技术委员会编.中国机械工业标准汇编弹簧卷.北京：中国标准出版社，1999.66 中国轻工模具网模具新闻 中国模具工业特点基本状况及情况 分析2006.4.117 太空模具网. 未来10年的模具发展趋势. 2005.11.248 中国金属加工网.冲压模具行业发展现状及技术趋势.2005.69 彭建声、秦晓刚编著.模具技术问答. 北京：机械工业出版社，199610 Kondo K.Parametric and Interactive Geometric Modeler Formechanical.Computer-Aeded Design.1990(10)34 河南机电高等专科学校毕业设计说明书毕业设计题目：型弯曲件的冲压工艺及模具设计系 部 材料工程系专 业 模具设计与制造 班 级 模具042 学生姓名 王桂周 学 号 0412226 指导教师 王强 于智宏 2007年 5月 23 日 毕 业 设 计（论 文）任 务 书1本毕业设计（论文）课题来源及应达到的目的：在完成该课题之后，应对冷冲压工艺生产较为熟悉，能熟练掌握相关设计手册的使用，能独立完成一套模具的设计及模具工作零件加工工艺的编制，能够运用模具设计软件完成模具装配图及零件图的绘制。2本毕业设计（论文）课题任务的内容和要求（包括原始数据、技术要求、工作要求等）：（1）了解目前国内外塑料模具的发展现状；（2）制件的结构工艺分析； （3）支架拐件冷冲模设计，并编写设计说明书一份；（3）绘制模具总装图一张，并画出非标准零件的零件图； （5）编制主要零件加工工艺过程卡。 原始资料：制件图及其尺寸见说明书：材料：A5 所在专业审查意见：负责人： 年 月 日系部意见：系领导： 年 月 日机械加工工艺过程卡（模具专业冲压模具课题适用）机械加工工艺过程卡片产品型号零（部）件图号产品名称零（部）件名称共（ ）页第（ ）页材料牌号 毛坯种类毛坯外型尺寸每个毛坯可制件数每台件数备注工序号工序名称工 序 内 容车间工段设备工 艺 装 备工时准终单件设计日期审核日期标准化日期会签日期标记记数更改文件号签字日期标记处数更该文件号毕业设计（论文）成绩毕业设计成绩指导老师认定成绩小组答辩成绩答辩成绩指导老师签字答辩委员会签字答辩委员会主任签字 毕业设计/论文任务书 题目： 内容：（1）（2）（3）（4）（5）（6） 原始资料:河南机电高等专科学校毕业设计说明书 摘 要本设计题目为型弯曲模设计，体现了典型型弯曲模的设计要求、内容及方向，有一定的设计意义。通过对该零件模具的设计，进一步加强了设计者弯曲模设计的基础知识，为设计更复杂的弯曲模具做好了铺垫和吸取了更深刻的经验。本设计运用弯曲成型工艺及模具设计的基础知识，首先分析了板材的性能要求，为选取模具的类型做好了准备；然后计算了弯曲件的弯曲力，便于选取压力机吨位及确定压力机型号；最后分析了弯曲件的特征，确定模具的设计参数、设计要点及顶出装置的选取。本设计采用了八字摆块复合模成型型件。复合模具有生产效率高，制件精度高等特点，特别适合大批量高精度生产。成型原理可划分为两个阶段：首先，凸模与凹模共同作用成型U形件；凹模继续下行，迫使摆块左右摆动动作，U型件被再次弯曲成型，最后成型型件，这种机构动作灵活可靠，设计方便，非常适合在本副模具中使用。关键词：弯曲模 凸模 凹模 摆块 AbstractThe requirement ，content and direction of the design of the bending dies parts are embodied on this bending dies design. The designers foundation knowledge of the bending dies design is reinforced and is able to design more complex injection mould through the design. Through the foundation knowledge, firstly, the composion and the performance of the flat sheet is analyzed to choose the type of the mould. Secondly, the volume of the bend is estimated to choose the press molding machine and to detemine the type press machine and tonnage of press. Lastly the character of the part is analyzed to determine the mould design parameter and design point and choose the ejection assembly. Swing block compound die is used in this design to form thepart.the compound die can produce pierced blanks to close flatness and dimensional tolerances. Compound diesproduce efficiency and part precision is hight. Especially fit for volume produce and hight precision produce.Moulding of the part is like this :Fist,behing punch and dies together operation, the part is form to the fast bending ;die is going down, swing block is flogged to work, and the second bending is begin. At last, the part is form to part. This devices action credibly and design conveniencly. So, it is adapted to be used on this mould extraordinarily.Keywords: bending dies , punch , dieg, swing block 3目 录摘要I绪论1第一章 弯曲件工艺分析4 1.1 弯曲件工艺性分析41.2 弯曲件研究思路 5第二章 弯曲工艺方案的确定 62.1 方案介绍62.2 方案分析8第三章 设计计算93.1 主要设计计算73.1.1弯曲件毛坯坯料尺寸的计算73.1.2弯曲应力计算113.1.3压料力的计算113.1.4压力机公称压力的确定123.2 弯曲模工作部分尺寸的设计123.2.1 凸模圆角半径的设计123.2.2 凹模圆角半径133.2.3 凹模深度 133.2.4 凹凸模间隙计算143.3 U 形弯曲凸凹模横向尺寸的设计143.4弹簧的选用163.4.1 每个弹簧力的计算163.4.2 弹簧预压缩量173.4.3 弹簧校核17第四章 模具类型的选择184.1模具结构选择184.2 定位方式的选择204.3 出件方式的设计20第五章 主要零件的设计215.1 工作零件的结构设计215.1.1凸模的结构草图215.1.2凸模主要尺寸的计算185.2 凹模的结构设计235.2.1 凹模主要尺寸的设计245.3 摆块的结构的设计255.3.1 摆块的结构草图25 5.3.2摆块的主要尺寸的设计265.4 定位零件的设计275.4.1 限位钉的设计285.5 定位块的设计29 5.6弹顶部件的设计305.6.1垫板的设计305.6.2 导板的设计30第六章 压力机的参数与较核31第七章 模具零件的加工工艺327.1 凸模的加工工艺过程 32 7.2 凹模的加工工艺过程 32 第八章 模具的装配33第九章 模具试冲34设计总结35致谢 36参考文献 37河南机电高等专科学校毕业设计评语学生姓名： 王桂周 班级: 模具042 学号： 0412226题 目： 型弯曲件的冲压工艺及模具设计 综合成绩： 指导者评语： 指导者(签字)： 年 月 日毕业设计评语评阅者评语： 评阅者(签字)： 年 月 日答辩委员会（小组）评语： 答辩委员会（小组）负责人(签字)： 年 月 日 Annals of the CIRP Vol. 56/1/2007 -269- doi:10.1016/j.cirp.2007.05.062Design of Hot Stamping Tools with Cooling System H. Hoffmann1 (2), H. So1, H. Steinbeiss11Institute of Metal Forming and Casting, Technische Universitt Mnchen, Garching, Germany Abstract Hot stamping with high strength steel is becoming more popular in automotive industry. In hot stamping, blanks are hot formed and press hardened in a water-cooled tool to achieve high strength. Hence, design of the tool with necessary cooling significantly influences the final properties of the blank and the process time. In this paper a new method based on systematic optimization to design cooling ducts in tool is introduced. The optimization procedure was coupled with FE analysis and a specific evolutionary algorithm. Through this procedure each tool component was separately optimized. Subsequently, the hot stamping process was simulated both thermally and thermo-mechanically with the combination of optimized solutions.Keywords:Hot Stamping, Finite element method (FEM), Optimization 1 INTRODUCTION In recent years, weight reduction while maintaining safety standards has been strongly emphasized in the automotive industry for building new models. Hot stamping of high strength steels for automotive inner body panels offers the possibility of fuel saving by weight reduction and enhances passenger safety due to its higher strength. In order to achieve high strength by hot stamping with high strength steels, blanks should be heated above austenitic temperature and then cooled rapidly such that the martensitic transformation will occur. Normally, the tools are heated up to 200C without active cooling systems in serial production 1. However, in hot forming processes, the tool temperature must maintain below 200C to achieve high strength. So far, very few studies have been conducted regarding the design of cooling systems in a hot stamping tool.This paper presents a systematic method to design hot stamping tools with cooling systems in optimal and fast manners, in which the cooling system is optimized with the help of FE analysis and a specific evolutionary algorithm. Subsequently, a series of hot forming processes was simulated thermally as well as thermo-mechanically to observe the heat transfer and the cooling rate through the optimized cooling system. In the hot stamping process the tool motion requires relatively short time compared to the whole process time. Therefore, thermal analysis of a series of hot stamping processes without considering the tool motion could be sufficient with reasonable accuracy and shorter computation time for quick design of the hot stamping tools with cooling system. However, thermo-mechanical analyses that include the motion of the punch and the forming process are necessary to enhance the accuracy of the predictions. In this paper, a crash relevant hot stamped component of a vehicle and its corresponding prototype of hot stamping tool are introduced in chapter 2. And the optimization procedure with FE analysis and evolutionary algorithm is introduced in chapter 3. Subsequently, the results of thermal and thermo-mechanical analyses with the optimized hot stamping tool are presented. 2 COOLING OF HOT STAMPING TOOL 2.1 Motivation To enhance the economical production procedure and good characteristics of the formed parts, hot stamping tools need to be designed optimally. Therefore, the main objective of this study is the optimal designing of an economical cooling system in hot stamping tools to obtain efficient cooling rate in the tool. So far, very few researches have been conducted regarding the design of cooling systems in hot stamping tools. Therefore, an advanced design method is required. Also, an adequate simulation model is required to perform the optimization and investigation of tools and products as fast and accurate as possible. 2.2 Characteristics of 22MnB5 In direct hot forming process, the quenchable boron-manganese alloyed steel 22MnB5 is commonly used. Also, 22MnB5 is one of the representative materials of ultra high strength steels. Therefore, in this study, aluminium pre-coated 22MnB5 sheet (Arcelors USIBOR) was considered as the blank material. The material 22MnB5 has a tensile strength of 600MPa approximately at the delivery state, and the tensile strength can be significantly increased by hot stamping process. Higher tensile strength is achieved in the hot stamping process by a rapid cooling at least at the rate of 27C/s 2. The initial sheet of 22MnB5 consisting of ferritic-perlitic microstructure must be austenitized before forming process in order to achieve a ductility of blank sheet. As the austenite cools very fast during quenching process martensite transformation will occur. This microstructure with martensite provides the hardened final product with a high tensile strength up to 1500 MPa. 2.3 Tool component and test part The components of the prototype hot stamping tool and its kinematics are shown in Figure 1 and the initial blank and the proposed test part in Figure 2. The initial blank has the dimension of 170mm x 430mm x 1.75mm and the draw depth of the proposed test part is 30mm. -270- faceplatecounter punchblank holderpunchfaceplate tabletableblankdistance boltsdiebarellsplungerFigure 1: Schematic of a test hot stamping tool. Initial thickness: 1.75mm430mm170mm400mm100mmDraw depth: 30mmFigure 2: Initial blank and drawn part. 2.4 Cooling systems in stamping tools The tool must be designed to cool efficiently in order to achieve maximum cooling rate and homogeneous temperature distribution of the hot stamped part. Hence, a cooling system needs to be integrated into the tools. The cooling system with cooling ducts near to the tool contour is currently well known as an efficient solution. However, the geometry of cooling ducts is restricted due to constraints in drilling and also the ducts should be placed as near as possible for efficient cooling but sufficiently away form the tool contour to avoid any deformation in the tool during the hot forming process. To guarantee good characteristics of the drawn part, the whole active parts of the tool (punch, die, blank holder and counter punch) need to be designed to cool sufficiently. 3 DESIGNING OF COOLING SYSTEMS 3.1 Optimization with Evolutionary Algorithm xsaboring positionminimum distance between loaded contour and cooling duct (x) between unloaded contour and cooling duct (a) between cooling ducts (s)loaded contourunloaded contourcoolant boreConstraints sealing pluginput parameters of cooling system number of cooling channels and coolant bores diameter of cooling ductevaluation criteria cooling intensity and uniform coolingOptimization (Evolutionary Algorithm)1 solution per given input ? separate optimizationSolutionFigure 3: Optimization procedure for each tool. The optimization procedure for design of a cooling system is presented in Figure 3. In this procedure, cooling channels can be optimized in each tool by a specific Evolutionary Algorithm (EA), which was developed at ISF (Institut fr Spannende Fertigung, Universitt Dortmund, Germany) for the optimization of injection molding tools and adapted for design of cooling systems in hot stamping tools 3,4. As constraints for optimization, the available sizes of connectors and plugs, the minimum wall thicknesses as well as the nonintersection of drill holes were considered. The admissible minimal distance between cooling duct and unloaded/loaded tool contour (a/x) and the minimal distance between cooling ducts (s)were determined through FE analyses. Parameters of the cooling system such as the number of channels (a chain of sequential drill holes), drill holes per channel and the diameter of the holes for each tool component were also provided as input parameters to the optimization. These input parameters can be obtained from existing design guidelines or through FE simulations. Based on the input parameters initial solution is generated randomly by EA or manually by the user. From the initial solution, the EA generates new solutions by recombination of current solutions and modifying them randomly. The defined constraints were subsequently used for the correction of the generated solutions and the elimination of inadmissible solutions. All the generated solutions were evaluated by optimum criteria such as efficient cooling rate and uniform cooling. Finally, the best solution was selected as optimized cooling channels for a selected tool component.3.2 Optimized cooling channels In our research, the selected diameters of ducts were 8mm and 12mm for punch, 8mm, 12mm and 16mm for die, 8mm and 10mm for counter punch and 8mm for blank holder. EA was used to place the cooling channels optimally according to the given input and constraints for each tool component. The optimized profiles of the channels for duct diameter of 8mm are shown in Figure 4. cab400mm100mm145mmpunchcounter punchdieblank holderababcab510mm260mmabc70mm510mmab260mma110mmcooling mediumplug380mma70mm250mmbcbdirection of cut viewFigure 4: Optimized cooling channels with 8mm duct diameter.4 EVALUATION OF THE OPTIMUM COOLING CHANNEL DESIGNS The design of cooling channels was generated by EA for each tool component with different bore diameters and their cooling performances were evaluated by using FE simulations.4.1 Thermal analysis In the design and development phase of hot stamping tools, it is important to estimate the hot stamping process qualitatively and quantitatively within a short time for -271- economic manufacturing of tools. For this purpose, two transient thermal simulations were carried out with ABAQUS/standard, which uses an implicit method. In this analysis steel 1.2379 was selected as a tool material. The simulation model comprises 4 tool components: punch, die, blank holder and counter punch. In Table 1, the selected combinations of tool components with optimized cooling channels are presented. The variant V1 is the combination of optimized tools with small cooling duct diameters, whereas variant V2 with large cooling duct diameters.V1V2punchcounter punchblank holder8mm8mm8mm8mm12mm10mm16mm8mmdiameter of cooling ductdieTable 1: Combinations of designed tools for FE analysis. In order to represent a series of production processes, a number of cycles of the hot stamping processes were simulated as a cycle heat transfer analysis. The Figure 5 shows the FE model including boundary conditions. cooling duct (c)Tc= 20?Chc= 4700W/m2?Ctool (t)Tt,0= 20?Cenvironment (e)Te= 20?Che= 3.6W/m2Ccounter punchblank holderpunchblankdieblank (b)Tb,0= 850?Cblank - tool? ?c= f (d,P)Figure 5: FE model and boundary conditions. This hot forming process for the prototype part was designed such that the cycle time is 30 sec. In a cycle, the punch movement for forming requires 3 sec, the tool is closed for 17 sec for quenching the blank and it takes another 10 sec for opening the tool and locating the next blank on the tool. However, in this thermal analysis, the tool motion and deformation of the blank was not considered to reduce the computation time. Hence, only heat transfer analysis was performed in a closed tool. In thermal analysis, the quenching process takes places 20 sec instead of 17 sec, because the motion of punch was not considered. It was assumed that the blank has an initial homogeneous temperature (Tb,0) of 850C due to free cooling from 950C during the transfer in environment. The initial tool temperature (Tt,0) was assumed as 20C at the first cycle and changes from cycle to cycle. The temperature of the cooling medium (Tc)was assumed as room temperature. Beside the boundary conditions, the required material properties of 22MnB5 were obtained from hot tensile test conducted at LFT (Lehrstuhl fr Fertigungstechnologie, Universitt Erlangen-Nrnberg, Germany), with whom a joint research on hot stamping is being conducted 2. In this analysis, convection from blank and tools to the environment (he), conduction within each tool, convection from tool into cooling channels (hc) and heat transfer from hot blank to tool (? ?c) were considered. Here, ? ?c, is the contact heat transfer coefficient (CHTC) which describes the amount of heat flux from blank into tools. This coefficient usually depends on the gap d between tool and blank and the contact pressure P. It increases usually as the contact pressure increases. However, in thermal analysis the pressure dependent CHTC was not available, but a gap dependent coefficient was used. CHTC was assumed as 5000W/m2C at zero distance between blank and tool (gap) and keeps constant until the gap increases beyond critical value. 4.2 Thermo-mechanical analysis Simulation of hot forming is different from conventional sheet metal forming simulation, in which the distribution of temperatures or stresses in tools is neglected. For fast and easy way to analyze the hot forming process the tool and the blank were modelled with shell elements as in other studies 5,6. In these studies, the temperatures could be distributed along the thickness of the shell element with the user-defined function of temperature, but the temperature within the tool was not considered. Also, in this simulation model the heating of tools in a series of hot stamping processes were not considered. Furthermore, the shell model for thermal contact problems is just adequate for relatively short contact time 6. Therefore, in our studies the tools and the blank were modelled with volume elements to simulate the sequential heat transfer in a series of processes. The thermo-mechanical simulation was conducted with ABAQUS/explicit. In comparison to the thermal analysis, the whole forming and quenching process were modelled and the dynamic temperature and stress responses of tools in contact with hot blank were simulated by using time-temperature dependent flow stress curves. The heat transfer could be more accurately expressed using pressure dependent CHTC at contact places which change during forming process. In addition, temperature dependent thermal conductivity and specific heat were also considered. However, in thermo-mechanical analysis, as the number of elements increases, the complexity of the FE problem significantly increases. In conventional forming simulation an adaptive mesh can be normally used to spare the simulation time and to obtain a more accurate solution in the contact area. However, adaptive mesh refinement causes instability during computation in thermo-mechanical analysis. Therefore, a refined mesh with higher punch velocity was considered to reduce the simulation time. The heat transfer coefficients were scaled accordingly to obtain the same heat flux 7. 5 SIMULATION RESULTS AND DISCUSSION 5.1 Thermal analysis Figure 6 shows the temperature changes in the tool components for 10 cycles at tool combination V1 and V2. T ? ?C400300100003001000300100diepunchtstsV1V2Figure 6: Temperature changes in heat transfer analysis. The results show that the hottest temperatures of the tools at the end of each cycle do not change almost after some cycles. The obtained cooling rates of the blank at the hottest point from 850C to 170C are 40C/s with V1 and 33C/s with V2 at 10th cycle and these are greater than the required minimum cooling rate of 27C/s. Furthermore, V1 leads to a more efficient cooling performance than V2. Better cooling performance for V1 compared to V2 can be explained with the geometric restrictions and the minimal wall thickness. A cooling duct with small diameter can be placed closer to the tool surface in a convex area and the amount of the cooling channels can be increased additionally. Usually, the heat dissipation in the convex area is slower than in concave area 6. The result shows also that the temperature of convex area in the punch -272- cools down slower than the concave areas in the die. Due to this fact, it can be concluded that the efficient cooling is most desired at convex area.5.2 Thermo-mechanical analysis The heat transfer with optimized tool components was simulated thermally at first. However, there was a simplification of a hot stamping process in thermal analysis. Therefore, a thermo-mechanical analysis for V1 was performed to observe the differences and the significance of modelling the punch movement. Temperature change curves at the hottest point from the end of the first cycle in the blank, die and punch are shown in Figure 7. The tool cooled further 10 sec after quenching and the temperature changes in the die and punch were presented for 30 sec. A coupled thermo-mechanical analysis was done using gap-pressure dependent CHTC. The results from thermal analysis shows a cooling rate of 92C/s from 850C to 170C in comparison to 75C/s from thermo-mechanical analysis. 4003001000diepunch05201000800400T ? ?C200Thermal analysisThermo-mechanical analysists15blank00530 0525 30ts1020251020tsT ? ?CFigure 7: Temperature changes in thermal and thermo-mechanical analysis (1th cycle). To verify the accuracy of a thermal analysis or to predict a serial production process more accurately a series of thermo-mechanical analysis was done. For this analysis the punch velocity was increased 10 times and 10 hot stamping processes were simulated. In Figure 8, the temperature change curves at the hottest point of the die and punch from a thermal and thermo-mechanical analysis are compared for 10 cycles. Finally, the temperature distributions in the bla