毕业论文落料拉深复合模设计

1、摘 要 在工业生产中冲压成形技术应用是很广泛的，板料冲压技术是金属加工的一种根本方法，它主要用于生产各种板料零件，具有生产效率高、重量轻、尺寸精度好、低本钱并且容易实现机械化和自动化等特点。本文针对筒形零件的落料工艺性和拉深工艺性，将其设计为落料拉深复合模。 其设计说明中包括了冲压件的工艺性分析、工艺方案的拟定、排样设计、拉深次数、模具结构形式的合理性分析、及模具工作尺寸的计算、冲压设备的选择。对于落料拉深复合模来说，成形凸凹模的设计也较重要。为了设计的合理化，尽可能选用了标准件，如模座，模架，导柱导套等。该论文中也对非标准的零件结构设计，并且附有相应的零件图，最后根据零件结构设计和生产零件的

2、要求生成了总装配图。关键词：复合模； 落料； 拉深； 装配图ABSTRACTStamping technology is widely applied in industrial production, sheet metal stamping is a kind of basic method of metal processing,it is used to produce all kinds of sheet metal parts, with high production efficiency, good dimensional accuracy and light weight,

3、low cost and easy to realize mechanization and automation, etc.This article in view of the cylindrical parts blanking technology and deep drawing process, the design of deep drawing compound die for blanking.Its design notes including stamping manufacturability analysis, process scheme of layout des

4、ign, drafting, drawing number, the rationality of the mould structure analysis, and the calculation of the die working size, the choice of stamping equipment.For blanking deep drawing die, the design of forming intensive also are quite important.To the standardization of design, as far as possible c

5、hoose the standard parts, such as mold, mold base, pressing machine, etc. Non-standard parts structure design is given at the same time, with the corresponding part drawing, finally according to the requirement of the parts structure design and production of parts to generate the general assembly dr

6、awing.Key words: Composite molding; Blanking; Drawing; Assembly drawing目 录前 言11. 工件分析21.1 分析工件冲压工艺性21.2 分析计算确定工艺方案31.2.1 确定工艺方案31.2.2 计算毛坯尺寸31.2.3 计算拉深次数31.3 主要工艺参数的计算31.3.1 确定排样、裁板方案452.1 计算工艺力，选设备52.2 模具工作局部尺寸计算53. 模具总体及零件设计73.1 模具总体设计773.2.1凹模厚度的计算：73.2.2拉深凸模长度的计算：773.3 模架及零件的选择83.4 标准零件的选择83.5 冷

7、冲压工艺规程卡片9114.1 落料凹模设计114.2 拉深凸模设计114.3 凸凹模设计124.4 刚性卸料板设计134.5 凸凹模垫板设计144.6 压边圈设计154.7 模柄设计164.8 导柱、导套设计174.9 打料块设计194.10 上模座设计204.11 下模座设计215. 模具装配图232525结 语27致 谢28参考文献29 前 言 冲压技术是通过模具使板材产生塑性变形而获得成品零件的一种成型工艺方法。由于冲压通常在冷态下进行的，因此也称冷冲压。金属加工的一种根本方法就是板料冲压，其用以生产各种板料零件，具有生产效率高、重量轻、尺寸精度好、本钱低并易于实现机械化和自动化等特点。

8、在现代汽车、拖拉机、电器电机、电子仪表、日用生活用品、航空航天以及国防工业等各个工业部门中均占有越来越重要的地位。 冲压加工具有以下特点：1.材料利用率高2.可加工薄壁、形状复杂的零件3冲压件在形状和尺寸精度方面互换性好4.能获得质量轻而强度高、刚性好的零件5。生产效率高，操作简单，容易实现机械自动化。由于冲压加工具有以上那些优点，因此在批量生产中得到了广泛应用，在现代化工业生产中占有特别重要的地位，是国防工业在加工生产中绝不能少的加工方法。但由于冲模制造一般是单件小批量生产，技术要求高，精度高的产品，制造本钱高，因此冲压生产只有在大批量生产的情况下才能获得好的经济效益。 到目前为止，我国冲压

9、技术与工业兴旺的国家相比还相对落后，主要原因是我国在冲压根底理论及成形工艺、模具设计、模具标准化、模具制造工艺和设备等方面与工业兴旺国家尚有相当大的差距，导致我国模具在寿命、加工精度、效率、生产周期等方面与先进工业兴旺国家的模具相比还是存在一定差距的。特别是在计算机辅助应用软件方面，我国用的CAD/CAM大多是进口的绘图软件，没有对其进行二次开发，自己开发的软件又缺乏通用性。 而国外，特别是美国、日本、瑞士和德国等国每年出口模具约占本国模具总生产量的三分之一。在日本，模具被誉为“进入富强社会的原始动力。在德国，模具那么冠名为“金属切削加工中的帝国。由此可见，模具工业将在国民经济开展过程中起到越

10、来越重要的作用。 而在冲模的设计和生产上，目前正朝着两个方向开展：一方面，为了适应高速、自动、高寿命、高精密及多功能、多工位方向开展，与此相对应的新型模具材料及其外表热处理技术，各种高效、数控、精密、自动化的模具加工机床和检测设备以及模具CAD/CAM技术也在迅速开展；与此同时，为了适应产品试制或小批量生产及更新换代的需要，锌基合金冲模、薄板冲模、聚氨醋橡胶冲模、组合冲模、钢带冲模等各种简易冲模及模具快速制造技术也开展迅速。 1. 工件分析 1.1 分析工件冲压工艺性零件图如下： 总体来说:材料为08号钢，料厚为1mm，制件尺寸精度IT14级，形状简单，尺寸较小，能大批量生产，属于普通冲压件。

11、 工艺分析： 该工件为圆筒件拉深，形状简单，工件的厚度也无严格要求，容易成型，可以设计成一副落料拉深复合模。 1.2 分析计算确定工艺方案 1.2.1 确定工艺方案 该工件包括根本工序：落料、拉深 方案一：先落料、再拉深，采用单工序模具。 方案二：落料+拉深复合模具。 方案三：落料+拉深级进冲压模具。 方案比拟： 对于方案一，模具结构简单，但要做两幅模具才能完成，本钱过高且降低工作效率。对于方案二，只需一副模具，模具制造也并不难，可将拉深、落料一次性完成，生产效率高，适合大批量生产。对于方案三，虽然只需一副模具，但模具结构复杂，送料困难，拉深工件质量不好。最终考虑还是方案二比拟好。 1.2.2

12、 计算毛坯尺寸 根据等面积原理，用解析法求该零件的毛坯直径，并且由于h/d=16.5/41=0.402<0.5较小所以不必考虑修边余量，由毛坯的直径公式： D= 板厚为1mm,按板厚中经计算。 d=41mm H=16.5mm r=5mm 1.2.3 计算拉深次数 1.577% 查表可知，可用压边圈也可不用，为了保证质量，还是采用压边圈。 拉深系数计算 查文献【1】P144表4.3：08钢首次拉深系数为0.5mm，> 可知该产品可以一次拉深成形。 拉深件高度计算：h=H+1.3 主要工艺参数的计算1.3.1 确定排样、裁板方案 为了操作方便，采用单排排样。 (1)冲裁件面积计算A=D

13、2 (2)条料宽度 查文献【1】P46表2.9 搭边值：条料两边 a =1 mm，进距方向 a1 = 0.8 mm 进距 h = D + a1 = 63.4 + 1 = 64.4 mm 条料宽度 b = D + 2a = 63.4 + 2× 查【1】P47表2.11，条料的偏差为0.6mm,即 查【2】P208表11-16，拟选用板料规格1×800×1000 假设纵裁： 条数 n1 每条个数n2 =(1000-1)/64.4=15个 余33 mm 每板总个数 12x15=180个 (3)进距s计算 进距 h = D + a1 = 63.4 + 0.8 = 64.2

14、 mm (4)材料利用率 =A/Bs*100=31.55/65.4*64.2=75% 2.1 计算工艺力，选设备 落料力计算：=1.3*199.1*300=77649NL 工件外轮廓周长 L=D=3.14*63.4=199mmT=1mm 卸料力的计算：=0.04*77649=3106N -卸料力系数查【1】P51表2.15取0.04拉深力计算： =3.14*40*1*350*1=43960N d-工件直径 -材料抗拉强度查【1】P19表1.6取350 K为修正系数取1推件力的计算：=0.55*43960=24178N 为推件力系数查【1】P51表2.15取0.55)=0.25*43960=10

15、990N 冲压工艺总力：=77649+43960+10990=132599N顶件力计算：=0.06*132599=7956N 为顶力系数查【1】P51表2.15取0.06公称压力计算： =24178+7956+3106+132599=167839N2.2 模具工作局部尺寸计算(1)落料相关计算 落料即为拉深件坯料按IT14级精度取极限偏差，尺寸取凸凹模直径尺寸为： ， 式中x按工件精度为IT14级而选定 x = 0.5；d 、p按制造精度IT6 IT7选定，取d = 0.02 mm ，p = 0.03 mm按【1】P35表2.5查得：Zmin=0.1, Zmax再按 没法满足间隙公差条件。重选

16、 那么 经检验上述设计合理。 (2)拉深相关计算 工件按未注公差的极限偏差考虑，且零件是标准内形尺寸，按IT14级公差处理，工件的内径尺寸取。 拉深凹模圆角半径计算： -凹模圆角半径 D-毛坯直径 t-料厚 d-凹模内径 拉深凸模圆角半径计算： 3. 模具总体及零件设计 3.1 模具总体设计 1模具类型选择： 分析工艺性，采用落料-拉深复合模生产效率较高。 2定位方式选择： 该模具采用条料进给，用刚性卸料板导料，送进步距采用挡料销。 3卸料、出件方式： 模具采用刚性卸料装置，正装复合模，在拉深完成后，用推件板将工件从拉深凸模推出。 4进料方式：采用前后进料方式。 5 压力中心确定：因为该零件落

17、料、拉深均为中心对称形状，压力中心都是在圆心位置，所以不用进行压力中心的计算。 3.2.1凹模厚度的计算：H=0.4*63.4=25.36 ,选标准厚度为28mm落料凹模的外形直径计算： 取标准为：125mm 3.2.2拉深凸模长度的计算：为了实现先落料后拉深，必须让拉深凸模端面的高度比落料凹模端面低，拉深凸模的长度L为：H=28+16-3=41mm 凸凹模的长度包括凸模的修模量及固定板与卸料板之间的平安距离，L=h1+h2+h=20+12+17+15=64mm L-凸凹模的长度 h1-凸凹模固定板的厚度 h2-卸料板厚度 -拉深高度 h-附加长度，平安距离取15 3.3 模架及零件的选择选择

18、滑动导向中间导柱圆形模架，再按其标准选择具体结构尺寸，查【2】P253表12-12，选取上模座 160×45 HT200下模座 160×50 HT200导柱 32×160 20钢导套 32×105×45 20钢凸凹模垫板厚度取6mm拉深凸模垫板模垫板厚度取6mm凸凹模固定板厚度取20mm拉深凸模固定板厚度取16mm刚性卸料板厚度取15mm凸缘式模柄 40×60 Q235模具闭合高度 =45+6+52+28+16+6+50+6=209mm选取开式双柱可倾压力机J23-25，压力机的最大装模为220mm，大于模具的闭合高度，满足要求。压力

19、机参数：公称压力：250KN滑块行程：65mm最大闭合高度：270mm连杆调节长度：55mm最大装模高度：220mm工作台尺寸：370X560mm垫板尺寸：50X200mm模柄孔尺寸：40X60 3.4 标准零件的选择 模柄的规格为：A40X80GB2862.1-81 材料：Q2352. 螺钉：选M10，长度根据模具结构定。3. 圆柱销：选10，长度由结构定。4.推杆的尺寸： 选取直径为10的推杆， 推杆的长度=模柄总长+凸凹模垫板厚度+凸凹模高-推件块厚 =70+6+64-9=131mm 取L=130mm 那么推件杆的尺寸为：10X130，材料为S45C, 热处理硬度：4348HRC 选择圆

20、柱头固定挡料销，其结构简单，制造方便 型号为A 6 (GB2866,11-81?冷冲模设计指导? 材料：S45C 热处理：4246HRC3.5 冷冲压工艺规程卡片冲压工艺规程卡片东华理工大学长江学院产品名称 工件名称 圆筒产量第1页产品图号 工件图号大批量共 1页材料牌号及技术规格08F毛料形状及尺寸选用板料 1×800×1000 工序号工序名称工 序 草 图工装名称设备检验要求工种备注1下料1×800×1000落料拉深复合模JB23-63 按草图检验2落料拉深落料拉深复合模250KN压力机按草图检验3检验按冲压件图检验原底图总号日期 更改标记编制校对核

21、对文件号签名 底图 总号签字签名日期日期 4.1 落料凹模设计材料选择为T10A，热处理硬度为 58-62HRC该零件有三个M10螺纹孔，以便与下模板固定；四个M6螺纹孔，用于与卸料板连接;有两个与下模板同时加工的销钉孔，用于定位；和一个挡料销;具体尺寸要求及零件材料等相关信息见零件图。 4.2 拉深凸模设计材料选择为T10A，热处理硬度为 58-62HRC配有有出气孔；具体尺寸要求及零件材料等相关信息见零件图。 4.3 凸凹模设计材料选择为Cr12MoV，热处理硬度为 58-62HRC；有两个模座及垫板同时配做的销孔；具体尺寸要求及零件材料等相关信息见零件图。 4.4 刚性卸料板设计设计要点

22、：内形与凸凹模间隙配合，与凸凹模单边间隙为0.5mm； 有四个螺纹孔与落料凹模连接； 厚度一般取12mm； 具体尺寸要求及零件材料等相关信息见零件图。 4.5 凸凹模垫板设计设计要点：设计内、外形尺寸； 有两个模座和凸凹模同时配做的销孔； 具体尺寸要求及零件材料等相关信息见零件图。 4.6 压边圈设计压边圈在该模具兼作顶料板。设计要点：内形须要与拉深凸模间隙配合，外形受落料凹模内孔限制； 与顶料杆相配合时可用作顶料板；具体尺寸要求及零件材料等相关信息见零件图。 4.7 模柄设计设计要点：根据冷冲模GB2862.3-81进行设计，具体尺寸及零件材料等相关信息见零件图。 4.8 导柱、导套设计设计

23、要点：根据GB-T2862.6-90进行设计，导柱、导套均选择为A型； 导柱型号为 32×160； 导套型号为32×105×45； 具体尺寸公差等参数见GB-T2862.6-90。导 柱导 套 4.9 打料块设计设计要点：前部外形与拉深凹模间隙配合而后部必须比前端外径大； 打料块和打料杆联合使用，靠两者的自重把工件打出来； 打料杆的长度=模柄总高+运动高度+上模板厚度+垫板厚度=70+35+40+6=151mm 4.10 上模座设计设计要点：根据冲模滑动导向中间导柱下模座GB-T2851.6-90进行设计； 具体尺寸要求及零件材料等相关信息见零件图。 4.11 下

24、模座设计设计要点：根据冲模滑动导向中间导柱下模座GB-T2851.6-90进行设计； 注意与凹模和顶料板的螺纹孔配合， 具体尺寸及零件材料等相关信息见零件图。 5. 模具装配图主 视 图俯 视 图三 维 图 (1)模柄的装配 此模具采用的是C型凸缘模柄，模柄与上模座的配合为H7/js6，将模柄装上模座，用角尺检查上模座上平面与模柄圆柱面的垂直度，误差不能大于0.03mm，然后用螺钉将其固定在上模座上。(2)导柱和导套的装配 导柱导套与上下模座都采用压入式连接，导套和导柱与模座的配合分别为H7/r6和R7/r6，压入时注意校正导柱对模座底面的垂直度，装配后的导柱的固定端面与下模座底面距离要求须大

25、于12mm。 (3)凸模和凹凸模的装配 本模具的凸模与凸模固定板的配合按H7/m6，凸模装入固定板后，其固定端面应和固定板的支承面应处于同一平面内，在压力机上调整好凸模与固定板的垂直度，将凸模压入固定板内，凸模对固定支承面的垂直度经检查合格后将凸模上端铆合，装配前在平面磨床上将凸模的上端面和固定板一起磨平，并以固定板支承面定位将凸模工作端面磨平。凹凸模与固定板的配合按H7/m6，总装前应将凹凸模压入固定板内，压在平面磨床将上下平面磨平。 (1)把组装上了凸模的固定板放在下模座上，按中心线打正固定板的位置，用平行夹头夹紧，通过螺钉孔在下模座上钻出锥窝，拆去凸模固定板，在下模座上按锥窝钻螺纹底孔并

26、攻丝，重新将凸模固定板置于下模座上并找正，用螺钉紧固，钻孔，打入销钉定位。 (2)配钻卸料螺钉孔时，将卸料板套在已装入固定板的凹凸模上，在固定板与卸料板之间垫上适当高度的等高垫铁，并用平行夹头将其夹紧，按卸料板上螺孔位置在模座上钻锥窝，然后拆开，按锥窝钻孔。 (3)用1中同样的方法配钻垫板和上模座上的螺钉孔，推杆孔，然后依次将垫片和卸料板、凹凸模、凹凸模固定板的组合部件装入上模座，用紧固螺钉固定，打入销钉定位。 (4)在落料凹模上装入挡料销，将推件块装入落料凹模，并将推杆装入固定板上的推杆孔，用紧固螺钉将落料凹模与凸模固定板固定，钻孔，打入销钉定位。 结 语本文是在刘洪泉老师的精心指导和大力支

27、持下完成的。老师以其严谨求实的治学态度对我产生重要影响。此次设计的是落料拉深复合模，从最开始的无从下手，经过慢慢地查资料，看参考书，思路渐渐清晰起来。从查阅模具的计算公式到模具工件零件的配合精度，每一步都经过了认真的查阅参考。查阅的过程正是我积累知识的过程，也是查漏补缺的好时机。这次毕业设计综合运用了本专业所学课程的理论知识和结合实际生产知识进行一次冲压模具设计，通过这次设计从而培养及提高了自己的独立设计能力，加强稳固了冲压模具设计有关课程所学的内容，掌握了冲压模具设计的方法及步骤，学会了冷冲压模具设计的根本的模具技能，知道了设计需先从分析零件的工艺性入手，再确定工艺方案，掌握了模具根本的结构

28、，提高了计算能力，绘图能力，并且对模具有关的课程都有全面的复习，独立思考能力也明显提高。但从中我也发现自己平时学习的缺乏和薄弱环节，正努力改正。在今后的学习和工作中，必须认真细心对待每件事，不断吸取经验，向更高的山峰进发。致 谢 本次毕业设计是我大学四年的最后一次大作业，能顺利完成是我学生时代的一次难忘的经历，在经过了查阅专业书籍，独立思考以及在老师的专业指导下，让我知道了设计一套合格的冲压模具是得费多大的心思和汗水。毕业设计的顺利完成，我要衷心感谢刘洪泉老师的帮助，正是在他耐心的指导下，我的毕业设计才能顺利完成，同时也教会了我解决问题的方法，先整体后局部，不断攻克困难，吸收经验。在即将毕业之

29、际，感谢老师们，感谢大学的每个老师，正是你们的悉心教导，我才能学到如此多知识。同时感谢学校为我们提供的良好学习环境，舒适的生活环境成长环境。衷心感谢你们，谢谢！参考文献1 贾俐俐. ?冲压工艺与模具设计? 北京，人民邮电出版社，20212 卢险峰. 冲压工艺模具学(第二版). 北京，机械工业出版社，20063 冲模设计手册编写组编著冲模设计手册北京：机械工业出版社，20004 涂光祺. ?精冲技术?. 北京：机械工业出版社，20065 徐政坤 ?冲压模具设计与制造? 化学工业出版社，2005，7 6 王秀凤编著.?冷冲压模具设计与制造?.北京：北京航空航天大学出版社，20057 成虹主编.?冲

30、压工艺与模具设计?.北京：高等教育出版社，20028 郑大中主编.?模具结构图册?. 北京：机械工业出版社，19959 李天佑 ?冲模图册? 北京： 机械工业出版社10 张荣清 ?模具设计与制造M? 北京 高等教育出版社，2021为你提供优秀的毕业论文参考资料，请您删除以下内容，O(_)O谢谢！2 Many people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the seven-day Chinese为你提供优秀的毕业论文设计参考资料，请您删除一下内容，

31、O(_)O谢谢！National Day holiday could be the best occasion to enjoy a destination. However, it can also be the easiest way to ruin how you feel about a place and you may become more fatigued after the holiday, due to battling the large crowds. During peak season, a dream about a place can turn to night

32、mare without careful planning, especially if you travel with children and older people. As most Chinese people will take the holiday to visit domestic tourist destinations, crowds and busy traffic are inevitable at most places. Also to be expected are increasing transport and accommodation prices, w

33、ith the possibility that there will be no rooms available. It is also common that you' ll wait in the line for one hour to get a ticket, and another two hours at the site, to only see a tiny bit of the place due to the crowds. Last year, 428 million tourists traveled in China over the

34、week-long holiday in October. Traveling during this period is a matter that needs thorough preparation. If you are short on time to plan the upcoming "Golden Week" it may not be a bad idea to avoid some of the most crowded places for now. There is always a place so fascinating that everyon

35、e yearns for. Arxan is a place like this. The beauty of Arxan is everlasting regardless of the changing of four seasons. Bestowed by nature, its spectacular seasonal landscape and mountains are just beyond word. Arxan is a crucial destination for the recommended travelling route, "China Inner M

36、ongolia Arxan Hailar Manzhouli". It is also the joint of the four prairies across the Sino-Mongolian border, where people gravitate towards the exotic atmosphere mixed with Chinese, Russian, and Mongolia elements. As a historic site for the Yitian Battle, Arxan still embodies the spirit of Geng

37、his Khan. Walking into Arxan, you will be amazed by a kaleidoscope of gorgeous colors all the year round - the Spring azaleas blooming red in the snow, the Summer sea wavering blue in the breeze, the Autumn leaves painted in yellow covering volcanic traces, and the Winter woods shining white on the

38、vast alpine snowscape. Hinggan League Arxan city is situated in the far eastern area of Inner Mongolia Autonomous Region. Its full name "Haren Arxan" means "hot holy water" in the Mongolian language. Arxan is a tourism city in the northern frontier with a blend of large forest, g

39、rand prairies, vast snowfield, heaven lake cluster, thermium, as well as volcanic cluster. It is a rare and unique ecotourism base filled with healthy sunshine, clean air and unspoiled green.  Nestled close to the country's largest virgin forest, and known for its spring and ecological envi

40、ronment, Arxan is marveled at by many tourists as the purest land on earth.  You cannot miss out the Autumn of Arxan. It is definitely the best with brightly-colored scenery full of emotions.  Autumn in the northern part of the country comes earlier than the South. A September rain followe

41、d by the footprints of Autumn brings more colors to the once emerald green mountain and blooming grassland.  Shutterbugs flock to see for themselves the marvel of splendid colors around the mountains and waters, many of whom have travel a long distance and even camp here only to capture a momen

42、t of the nature wonder.  The silver birch turns golden, while the larch is still proudly green. You will find yourself drowned in the intoxicating red of the wild fruits as well as the glamour of flowers in full blown. And your heart will be lingering on the woods as it's time for the wild

43、fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If it rains heavily on Saturday night, some elderly Chinese will say it is because Zhinu, or the Weaving Maid, is crying on the day she met her husband Niulang, or the

44、 Cowherd, on the Milky Way. Most Chinese remember being told this romantic tragedy when they were children on Qixi, or the Seventh Night Festival, which falls on the seventh day of the seventh lunar month, which is usually in early August. This year it falls on Saturday, August 2. Folklore Story As

45、the story goes, once there was a cowherd, Niulang, who lived with his elder brother and sister-in-law. But she disliked and abused him, and the boy was forced to leave home with only an old cow for company. The cow, however, was a former god who had violated imperial rules and was sent to earth in b

46、ovine form. One day the cow led Niulang to a lake where fairies took a bath on earth. Among them was Zhinu, the most beautiful fairy and a skilled seamstress. The two fell in love at first sight and were soon married. They had a son and daughter and their happy life was held up as an example for hun

47、dreds of years in China. Yet in the eyes of the Jade Emperor, the Supreme Deity in Taoism, marriage between a mortal and fairy was strictly forbidden. He ordered the heaven troop to catch Zhinu back. Niulang grew desperate when he discovered Zhinu had been taken back to heaven. Driven by Niulang'

48、;s misery, the cow told him to turn its hide into a pair of shoes after it died. The magic shoes whisked Niulang, who carried his two children in baskets strung from a shoulder pole, off on a chase after the empress. The pursuit enraged the empress, who took her hairpin and slashed it across the sky

49、 creating the Milky Way which separated husband from wife. But all was not lost as magpies, moved by their love and devotion, formed a bridge across the Milky Way to reunite the family. Even the Jade Emperor was touched, and allowed Niulang and Zhinu to meet once a year on the seventh night of the s

50、eventh month. This is how Qixi came to be. The festival can be traced back to the Han Dynasty (206 BC-AD 220). Traditionally, people would look up at the sky and find a bright star in the constellation Aquila as well as the star Vega, which are identified as Niulang and Zhinu. The two stars shine on

51、 opposite sides of the Milky Way. Customs In bygone days, Qixi was not only a special day for lovers, but also for girls. It is also known as the "Begging for Skills Festival" or "Daughters' Festival." In this day, girls will throw a sewing needle into a bowl full of water on

52、 the night of Qixi as a test of embroidery skills. If the needle floats on top of the water instead of sinking, it proves the girl is a skilled embroiders. Single women also pray for finding a good husband in the future. And the newly married women pray to become pregnant quickly. Tradition transfor

53、med The love story of Niulang and Zhinu, and the Qixi Festival have been handed down for generations. Yet these ancient traditions and customs are slowly dying out. Many modern Chinese, particularly youngsters, seem to know more about St Valentine's Day on February 14, characterized by bouquets

54、of roses, chocolates and romantic candlelight dinners, than they do about their home-grown day for lovers. Even Qixi is nowadays referred to as the "Chinese Valentine's Day." More and more young Chinese people begin to celebrate this day in a very similar way as that in western countri

55、es. Fewer people than ever will gaze at the heavens on Saturday to pick out the two stars shining bright on either side of the Milky Way, that is, if people even know on which day Qixi falls. There are ready reminders dotted about, in the form of big ads saying "Sales on Chinese Valentine's Day!" in s