毕业论文-塑料底座注射模设计.doc

郑州理工职业学院 塑料底座注射模设计（论文） 系 部： 机械工程系 姓 名： 学 号： 专 业： 模具设计与制造 指导老师： 摘 要 对塑料底座注射模结构采用中心浇口进料，采用一模一腔的模具结构， 材料采用流动性能差的PC塑料，通过对塑件的分析，注射机的选定，浇注系统的设计，成型零件的设计计算，脱模推出机构的设计，以及冷却系统的设计和导向地位机构的设计，给出了生产底座的一个实际参考设计生产流程。通过本设计，可以对注塑模具有一个初步的认识，注意到设计中的某些细节问题，了解模具结构及其工作原理；为以后从事本行业打下了良好的理论基础。此次设计的过程中查阅了大量的模具设计资料，通过模具的设计与应用，同原有的设计方法相比，模具的应用提升了产品的质量，模具整体设计的思路和要求符合现代设计潮流和未来的发展方向。关键词: PC；一模一腔；中心浇口；模具设计 ABSTRACT base injection mould structure adopts center gate; Selected a mould for four cavity die structure, and selected the medium flow not well PC plastic for filling mold, improve the design compact and practical efficiency; PC Based on the analysis of the plastic parts, injection machine selection of the design of the shunt way, Lord, molding parts design calculation of mechanism design, stripping out, and the cooling system design and guide mechanism design, status are given a production of plastics base actual reference design of the production process.The mould designprocess .Through the design and application of the mold ,the processing technology ，compared with previous technology ,which increase the quality of the product. The overall design mentalityand request conform to the modern design tidal and development direction of the future.Keywords: pc; plastics base; center gate; mold design. 目 录一、塑件成型工艺性分析5 1.塑件的分析5 2.注射成型过程6二、拟定模具的结构形式和初选注射机7 1.分型面位置的确定7 2.注射量的计算7 3.选择注射机8三、浇注系统的设计9 1.浇注系统的设计原则9 2.分流道的设计10 3.冷料穴的设计10四、成型零件的结构设计及计算11 1.成型零件的结构设计11 2.成型零件钢材的选用12 3.凹模深度尺寸的计算12五、脱模推出机构的设计13 1.脱模力的计算13 2.推出方式的确定13六、排气槽的设计15七、导向与定位机构的设计16 1.导柱导向机构16八、零件的加工工艺过程17 1.小型芯制造工艺过程：17 2.型腔制造工艺过程17九、设计小结20参考文献21致谢22 一、 塑件成型工艺性分析 1.塑件的分析 （1）外形尺寸 该塑件壁厚较厚，平均壁厚约为30mm，结构较简单，对称度好，只需做几个型芯即可，塑件为热塑性塑料，流动性差，适于螺杆式注射机注射成型。(2) 精度等级 该塑件重要尺寸和次重要尺寸精度等级均为MT4，由以上分析可见该零件的尺寸精度中等，对应的模具相关零件的尺寸加工可以保证。(3) 脱模斜度 pc的成型性能良好，成型收缩率较小，其脱模斜度根据参考文献1中表2-19可知型腔的脱模斜度在，型芯的在，pc的流动性差，为使注射充型流畅，选择塑件上型芯和凹模的统一脱模斜度为。 图1 塑件图 2.注射成型过程 （1）成型前准备。对PC的色泽、粒度和均匀度等进行检验，成型前必须预干燥，水分含量应低于0.02%，微量水份在高温下加工会使制品产生白浊色泽，银丝和气泡。常用方法是循环鼓风干燥，温度控制是120，时间812h以上。 （2）注射过程。塑料在注射机料筒内经过加热、塑化达到流动状态后，由模具的浇注系统进入模具的型腔成型，其过程分为充模、压实、保压、倒流和冷却五个阶段。 （3）塑件的后处理（退火）。退火处理的方法为红外线灯、烘箱，处理温度为100130，处理时间为2h8h。 二、拟定模具的结构形式和初选注射机 1.分型面位置的确定 通过对塑件结构形式的分析，分型面应选在塑件截面积最大，且有利 开 模，其位置如图2所示。图2 分型面的选择 2.注射量的计算通过Pro/E建模分析得塑件质量属性如图3所示。图3 塑件质量属性 塑件体积： 塑件质量：=1.21745.4=2094.4g 式中，可根据参考文献3表9-6取为1.20。 3.选择注射机 根据以上计算得出在一次注射过程中，注入模具型腔的塑料的总体积为=57.6，由参考文献2式4-18，=/0.8=2269/0.8=2836。根据以上的计算，查参考文献3中表13-1，初步选定公称注射量为3000，注射机型号为XZY-3000的螺杆式注射机，其主要技术参数见表2。技术指标参数技术指标参数理论注射量螺杆柱塞直径/mm注射压力注射时间s塑化能力锁模力/KN喷嘴口直径/mm3000g/cm31201153.8806308拉杆内向距/mm 移模行程/mm最大模具厚度/mm最小模具厚度/mm锁模形式模具定位孔直径/mm喷嘴球半径/mm9008001120680400充压式25025表2注射机主要技术参数 模具型腔内的胀型力，则 =268.540=1074.1kN 式中，是型腔的平均计算压力值。是模具型腔内的压力，通常取注射压力的20%50%，大致范围在25MPa40MPa。对于黏度较大的精度较高的塑件制品应取较大值。ABS属于中等黏度塑料切精度要求不高，故将取为40MPa。由表1 可知注射机的公称锁模力是=630kN，锁模力安全系数=1.11.2这里取=1.2，则取=1.2=1.21074.1=1289kN所以注射机锁模力满足要求。对于其它安装尺寸的校核要等到模架选定，结构尺寸确定后方可进行。 三、浇注系统的设计 1.浇注系统的设计原则 所谓注射模的浇注系统，是塑料熔体从注射机喷嘴射出后达到型腔之前在模具内流经的通道。其主要作用是使塑料熔体平稳而有序地充填到型腔中，以获得组织致密、外形轮廓清晰的塑件。它分为普通流道浇注系统和热流道浇注系统。浇注系统设计原则为： （1）重点考虑型腔布局。 （2）热量及压力损失要小，为此浇注系统流程应尽可能短，截面尺寸应尽可能弯折尽量少，表面粗糙度要低。 （3）均衡进料，即分流道尽可能采用平衡式布置。 （4）塑料耗量要少，满足各型腔充满的前提下，浇注系统容积尽量小，以减少塑料耗量。 （5）消除冷料，浇注系统应能收集温度较低的“冷料”。 （6）排气良好。 （7）防止塑件出现缺陷，避免熔体出现充填不足或塑件出现气孔、缩孔、残余应力。 （8）保证塑件外观质量。 （9）较高的生产效率。 该底座的注塑模具采用普通流道浇注系统，它包括：主流道、分流道、冷料井、浇口。为了满足塑件外观质量要求, 进料浇口开设在塑件的中间孔的圆环里。为了降低塑料熔体的压力和减少热量损失,流道应尽量短,同时为方便塑件的脱模, 应使开模时塑件滞留于动模一侧, 然后借助开模力驱动顶出装置将塑件推出。因为塑件的体积较大，对称度高，且中间带有比主流道直径大的孔，故该模具可以采用轮辐式浇口。 2.分流道的设计为尽量减少在流道内的压力损失和尽可能避免熔体温度降低，同时还要考虑减少分流道的容积和压力平衡，因此采用平衡式分流道。 。3.冷料穴的设计 冷料穴位于主流道正对面的大型芯上，其主要作用是收集熔体前锋的冷料，防止冷料进入模具型腔而影响制品的表面质量。本设计主流道冷料穴，冷料穴的直径宜稍大于主流道大端直径，深度约为直径的11.5倍。 四、成型零件的结构设计及计算 1.成型零件的结构设计 (1)凹模的结构设计： 凹模是成型制品的外表面的成型零件。按凹模结构的不同可将其分为整体式、整体嵌入式、组合式、和镶拼式四种。根据塑件的结构，选用的是整体式凹模，它是由一整块金属材料（也称定模板或凹模板）直接加工而成。其特点是为非穿通式模体，强度好，不易变形。但由于加工困难，故只适用于小型且形状简单的塑件成型。此时可省去定模座板根据岁塑件的结构分析，本设计采用整体嵌入式凹模，如图4所示。图4 整体嵌入式凹模 (2)动模凸凹模的结构设计： 凸凹模通常可以分为整体式和组合式两种类型。通过对塑件的结构分析可知，该塑件的型芯有多个：一个是成型塑件的内表面的大型芯，因包紧力大所以设在动模部分，另外四个小型芯设计时也将其放在动模部分，如图5所示；所以总体来说，该动模凸凹模的结构应属于组合式。图5 动模凸凹模 2.成型零件钢材的选用 根据对成型塑件的综合分析，该塑件的成型零件要有足够的刚度、强度、耐磨性及良好的抗疲劳性能，同时考虑它的机械加工性能和抛旋旋旋光性能。又因为该塑件为大批量生产，所以构成型腔的凹模钢材选用45钢。对于成型塑件内表面的大、小型芯来说，由于脱模时与塑件的磨损严重，因此钢材选用40Cr。 3.凹模深度尺寸的计算 塑件高度方向尺寸的转换： 型腔的最大深度mm，相应的制作公差mm，磨损后塑件尺寸变大的尺寸计算 mm 五、脱模推出机构的设计 在注射成型的每一循环中，都必须使塑件从模具型腔中或型芯上脱出，模具中的这种脱出塑件的机构称为脱模机构。模具脱模方式按推出零件分：推杆脱模、推管脱模、推件板脱模、推块脱模、成型零件脱模和多元联合式脱模六种。本塑件结构简单，根据塑件的结构工艺性可采用推件板推出、推杆推出、或推件板加推杆推出的综合推出方式，根据脱模力计算来确定。1. 脱模力的计算 （1）32小型芯脱模力因为=r/t=16/16=110，所以此处视为厚壁圆筒塑件， =1877.1N 式中=0.667 因为有四个小型芯，所以脱模力为1877.14=7508.4 N (2) 总脱模力的大小 F=12834.4+7508.4+4458.3=24801N. 另外考虑肋板收缩等因数的影响，可以按计算脱模力乘以一个不太大的系数，此处考虑为1.2 ， 所以推出应力：=1.2F=29761N 2.推出方式的确定 5.1 推杆材料 推杆的常用材料有钢、或碳素工具钢，推杆头部需淬火处理，硬度在50HRC以上，表面粗糙度在Ra1.6m。 5.2 校核推出应力1）推出面积 设14mm的圆推杆设置8根，那么推出面积为 =1230.9mm2 ； 2） 推出应力 MPa 所以推杆能够安全推出，不会出现顶白顶破的可能。上式查文献3表2-12得=26MPa 为推杆作用在塑件表面上的接触许用应力，大致是该种塑料常温下拉伸屈服应力的1/2。 图6 推杆六、排气槽的设计在注射成型过程中，模具内除了型腔和浇注系统中原有的空气外，还有塑料受热或凝固产生的低分子挥发气体，这些气体若不能顺利排出，则可能因充填时气体被压缩而产生高温，引起塑件局部炭化烧焦，或使塑料熔接不良而引起缺陷。注射的排气方式，大多数情况下是利用模具分型面或配合间隙自然排气，只在特殊情况下采用开设排气槽的方式。该塑件由于采用中心浇口进料熔体经塑件由上往下充满型腔，动模凸凹模上有八根推杆，其配合间隙可作为气体排出方式，不会在底部产生憋气现象。同时，气体会沿这分型、型芯和推件板之间的间隙向外排出。 七、导向与定位机构的设计注射模的导向机构用于动模、定模之间的开合模导向和脱模机构的运动导向。按作用分为模外定位和模内定位。模外定位是通过定位圈与注射机相配合，是模具的浇口套能与注射机喷嘴精确定位；而模内定位机构则通过导柱导套进行合模定位。锥面定位则用于动、定模之间的精密定位。本模具所成型的塑件比较简单，模具定位精度要求不是很高，因此可采用木架本身所自带的定位机构。 1. 导柱导向机构 模具导柱导向的导柱、导套结构，适用于精度要求高、生产批量大的模具。同时在设计导柱和导套时还应注意以下几点： (1) 导柱应合理的均布在模具分型面的四周，导柱中心至模具外缘应有足够的距离，以保证模具的强度。 (2) 导柱的长度应比型芯端面高出68mm，以免型芯进入凹模时与凹模相碰而损坏。 (3) 导柱和导套应有足够的耐磨度和强度，导柱常采用20#低碳钢经渗碳0.50.8 mm,淬火4855HRC,也可用T8A、T10A碳素工具钢,经淬火处理，硬度达到5055HRC。导套一般采用T10A或者经过渗碳处理20钢，热处理5055HRC，公差采用6级。 (4) 除了动模、定模之间设导柱、导套外，一般还在动模座板与推反之间设置导柱和导套，以保证推出机构的下常运动。 (5) 导柱的直径应根据模具大小而决定，可参考标准模架数据选取。 八、零件的加工工艺过程1.小型芯制造工艺过程：小型芯如下图所示： 图7小型芯工艺过程如下：1、备料：40Cr dL 45200mm圆钢2、粗车：以左端面为基准面，用夹心轴和尾针固定圆钢，先车至dL 42200mm,留余量1至2mm，于离基准面20毫米处，向右车至dL32.4180mm，留加工余量12毫米，于左端面167.31毫米处， 向右车至dL为1628.38MM，车断。3、热处理：退火处理，消除应力。4、半精车：车削外圆直径至实际尺寸。5、磨削：用心轴装夹，粗、精磨各外圆至图纸要求。6、热处理：进行渗碳处理，淬火后硬度为54-58HRC7、抛光。2.型腔制造工艺过程型腔如下图所示： 图8凹模工艺过程如下：1.备料： LBh 275275120mm 45号钢。2.粗磨：磨外平面至LBh 273273118mm，留余量，保证上下端面不超过0.05。3.划线:确定下平面距边缘长和宽为35.9mm四个交汇点，并连接相邻的两点，在直角处划出半径为31mm的圆角。划出各处投影在平面圆的圆心所在的直线，交点即为圆心。划出上平面的中心线。4.粗铣：在其中一个交汇点沿着划线铣出深度为80mm的型腔，留余量。5.钻孔：除左端面外在各个端面圆心先铣出直径为12mm、深度为13mm的大孔，在距离A平面为90mm和180mm的圆心处钻直径为10mm，深度为28mm的盲孔，在上平面中心线的交汇处钻直径为30mm的通孔。6.热处理：淬火，硬度为43-48 HRC7.磨：磨外平面至图纸实际要求，并保证A平面与B平面的垂直度。8.精铣：铣内型腔，使其粗糙度达到0.8。9.精铰：使直径为30mm的内型腔达到所需精度要求。10、抛光。11.设计小结 通过这次系统的注射模的设计，使我对模具设计工作有了更深层次的认识，即：模具不是只为设计而设计，要统筹规划，全盘考虑。这次设计使我能够理论联系实际，多方面、多角度地去感知、体会书本上比较抽象的理论知识。在指导老师及关心与帮助下，我的做事效率得到了一定的提高，独立思考并解决问题的能力得到了加强，培养了实际动手能力。我更进一步的了解了注射模的结构及各工作零部件的设计原则和设计要点，了解了注射模具设计的一般程序。进行塑料产品的模具设计首先要对成型制品进行分析，再考虑浇注系统、型腔的分布、导向推出机构等后续工作。通过制品的零件图就可以了解制品的设计要求。对形态复杂和精度要求较高的制品，有必要了解制品的使用目的、外观及装配要求，以便从塑料品种的流动性、收缩率，透明性和制品的机械强度、尺寸公差、表面粗糙度、嵌件形式等各方面考虑注射成型工艺的可行性和经济性。模具的结构设计要求经济合理，认真掌握各种注射模具的设计的普遍的规律，可以缩短模具设计周期，提高模具设计的水平。收获大概可概括为以下几点：1、 培养了分析问题和解决问题的能力从设计的开始，就有意识地培养自己独立思考问题、发现问题并解决问题的能力。大到模具的整体布局，小到排气槽的设置、冷料穴的长短，都要经过认真思考，才能拿出相对比较成熟的方案。2、 锻炼了实际动手能力在整个的设计过程中，翻阅了大量的文献资料，参考了大量的书籍，除了获得设计所需的数据外，还学到了其它许多的知识。更重要的是锻炼了自己的动手能力和借助工具书解决实际问题的能力。授人以鱼，不如授人以渔，我相信这些能力在我今后的工作和生活能定能让我受益匪浅。3、 绘图水平得到了提高通过做设计这一期间的实际操作及练习，学到了很多具体的绘图细节。譬如：虚线、点画线的画法及线条的粗细；剖线、剖面线的画法及线条粗细；标题栏的画法及明细表的编排、技术要求等。此外，绘图的速度也得到了进一步的提高，各种快捷键的操作也越来越熟练。 参考文献1 高军，李熹平，高玉田，褚兴荣. 注塑成型工艺分析及模具设计M. 北京：化学工业出版社. 2009.2 叶久新，王群. 塑料成型工艺及模具设计M. 北京：机械工业出版社. 2007.3 伍先明，张蓉. 塑料模具设计指导M. 北京：国防工业出版社. 2006.4 冯炳尧，韩泰荣，蒋文森 . 模具设计及制造简明手册M. 第二版.上海：上海科学技术出版社. 2002.5 塑料模具设计手册编写组. 塑料模设计手册M. 第二版. 北京：机械工业出版社. 1999.6 唐志玉，李德群，徐佩弦. 塑料模具设计师指南M. 北京：国防工业出版社.1999.7 陈锡栋，周小玉. 实用模具技术手册M. 北京：机械工业出版社. 2003.8 詹友刚. ProE/ENGINEER 中文野火版5.0模具设计教程M. 第二版. 北京：机械工业出版社. 2010.9 冯炳虎，韩泰荣，殷振海，蒋文森.模具设计与制造简明手册M. 上海：上海科学技术出版社.1991.10 王卫卫. 材料成型设备M. 北京：机械工业出版社. 2010.致 谢首先要感谢母校多年来对我的培养和教育，让我在这几年的大学生活里，不仅学习了科学文化知识，还学会了许多为人处世的道理，提高了自己分析问题和解决问题的能力。其次要感谢老师们多年来的辛勤教诲，正是因为他们的默默付出，才有我们的今天，特别是要感谢我的指导老师唐田秋副教授，在他的悉心指导和帮助下我才能顺利地完成我的毕业设计。同时也要感谢我同窗及好友多年来对我的关心和帮助！由于准备的时间较为仓促，资料查询方面不尽全面，本设计之中存在许多不足之处，还望各位专家、教授不吝指教。再次谢谢你们！ 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，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 nightmare 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, with the possibility that there will be no rooms available. It is also common that youllwait 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 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 everyone 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 Mongolia 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 Genghis 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 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, grand 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 countrys largest virgin forest, and known for its spring and ecological environment, 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 followed 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 moment 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 its time for the wild fruits to ripe. The picturesque Arxan in Autumn is indeed a fairyland only exists in a dream that satisfies all your fantasies. If itrains 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 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 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 bovine 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 hundreds 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 Niulangs 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 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 seventh 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 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 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 transformed 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 Valentines Day on February 14, characterized by bouquets 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 Valentines Day. More and more young Chinese people begin to celebrate this day in a very similar way as that in western countries. 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 Valentines Day! in shops, hotels and restaurants. But few young women will mark the festival with their boyfriends, or take part in traditional activities to pray for cleverness. A large-scale of exhibition on the Silk Road opened to the public in the National Museum on Thursday. The exhibition displays more than 400 treasures from Shaanxi province, Gansu province and 14 other regions. It is largest scale exhibition that shows the history of the Silk Road in recent years. AsAPECis going on in Beijing, the exhibit aims to show the world this brilliant section of history. The Silk Road is a series of trade and cultural transmission routes that were central to cultural interaction through regions of the Asian continent. It connected the West and East by linking traders, merchants, pilgrims, monks, soldiers, nomads, an