本科畢業(yè)論文十字軸夾具課程設(shè)計(jì)包含全套圖紙及工序卡

1、 航空制造工程學(xué)院機(jī)械制造工藝課程設(shè)計(jì)設(shè)計(jì)課題：十字軸零件機(jī)械加工工藝規(guī)程設(shè) 專業(yè)： 機(jī)械設(shè)計(jì)制造及其自動(dòng)化 班級(jí)： 姓名： 學(xué)號(hào)： 評(píng)分： 指導(dǎo)老師：（簽字） 2013年11月18日 目 錄1零件的工藝分析12機(jī)械加工工藝設(shè)計(jì)22.1確定生產(chǎn)類型22.2確定毛坯2確定毛坯種類22.2.2確定鍛件加工余量及形狀33工藝規(guī)程設(shè)計(jì)43.1選擇定位基準(zhǔn)43.2制定工藝路線43.3表面加工方法的確定53.4加工階段的劃分53.5工序順序的安排63.6確定工藝路線64機(jī)械加工余量、工序尺寸及公差的確定74、1工序1銑四軸端面74、2工序2粗車四軸外圓84、3工序3半精車四軸外圓94、4工序4鉆孔，攻螺紋

2、，锪錐面94、5工序5鉆四軸向軸中心孔，锪錐面104、6工序6滲碳淬火114、7工序7精磨四軸外圓、端面115夾具設(shè)計(jì)125.1定位基準(zhǔn)的選擇125.2定位加緊方案125.3 夾具元設(shè)計(jì)件的計(jì)算135.3.1夾緊力作用點(diǎn)135.3.2夾緊力的方向135.3.3夾緊方案14 5.4 夾具裝配圖的繪制15 5.4 夾具體主要零件圖的繪制166體會(huì)與展望197參考文獻(xiàn)191零件的工藝分析 零件的材料為20GrMoTi，需要模鍛，模鍛性能優(yōu)良，工藝較復(fù)雜，但尺寸精確，加工余量少，為此以下是十字軸需要加工的表面以及加工表面之間的位置要求：1、四處25外圓及四個(gè)8、6的內(nèi)孔、2、右端面5060內(nèi)孔及M8絲

3、孔。3、25外圓的同軸度為0.007，位置度為0.02，兩端的對(duì)稱度均為0.05.由上面分析可知，可以先上四爪卡盤粗車，然后上彎板采用專用夾具壓緊、找正進(jìn)行加工，并且保證形位公差精度要求。并且此零件沒有復(fù)雜的加工曲面，所以根據(jù)上述技術(shù)要求采用常規(guī)的加工工藝均可保證。 圖1、十字軸零件圖2機(jī)械加工工藝設(shè)計(jì)2.1確定生產(chǎn)類型 已知此十字軸零件的生產(chǎn)綱領(lǐng)為5000件/年，零件的質(zhì)量是0.83Kg/個(gè)，查機(jī)械制造工藝設(shè)計(jì)簡(jiǎn)明手冊(cè)第2頁表1.1-2，可確定該撥叉生產(chǎn)類型為中批生產(chǎn)，所以初步確定工藝安排為：加工過程劃分階段；工序適當(dāng)集中；加工設(shè)備以通用設(shè)備為主，大量采用專用工裝。2.2確定毛坯確定毛坯種類

4、零件結(jié)構(gòu)又比較簡(jiǎn)單，生產(chǎn)類型為中批生產(chǎn)，故選擇鍛模鍛造毛坯。查機(jī)械制造工藝設(shè)計(jì)簡(jiǎn)明手冊(cè)第41頁表2.2-5,選用鑄鍛件尺寸公差等級(jí)為CT-10。毛坯尺寸11411429；毛坯圖如下：2.2.2確定鍛件加工余量及形狀查機(jī)械制造工藝設(shè)計(jì)簡(jiǎn)明手冊(cè)第41頁表2.2-5，選用加工余量為MA-H級(jí)，并查表2.2-4確定各個(gè)加工面的鍛件機(jī)械加工余量， 如下表所示：簡(jiǎn) 圖加工面代號(hào)基本尺寸加工余量等級(jí)加工余量說明a25H2雙 側(cè)加 工b25H雙 側(cè)加 工c25H3雙 側(cè)加 工d25H3雙 側(cè)加 工3工藝規(guī)程設(shè)計(jì)3.1選擇定位基準(zhǔn)（1）粗基準(zhǔn)的選擇：作為粗基準(zhǔn)的表面應(yīng)平整，沒有飛邊、毛刺或其他表面缺欠。該工件選

5、擇25外圓面和左端面作為粗基準(zhǔn)。采用左端面作粗基準(zhǔn)加工右端面，可以為后續(xù)工序準(zhǔn)備好精基準(zhǔn)（2）精基準(zhǔn)的選擇：考慮要保證零件的加工精度和裝夾準(zhǔn)確方便，依據(jù)“基準(zhǔn)重合”原則和“基準(zhǔn)統(tǒng)一”原則，以粗加工后25的軸線為主要的定位精基準(zhǔn)，采用小彎板為輔助的定位精基準(zhǔn)。3.2制定工藝路線生產(chǎn)過程是指將原材料轉(zhuǎn)變?yōu)槌善返娜^程。它包括原材料的準(zhǔn)備、運(yùn)輸和保存，生產(chǎn)的準(zhǔn)備，毛坯的制造，毛坯經(jīng)過加工、熱處理而成為零件，零件、部件經(jīng)裝配成為產(chǎn)品，機(jī)械的質(zhì)量檢查及其運(yùn)行試驗(yàn)、調(diào)試，機(jī)械的油漆與包裝等。工藝過程是指在生產(chǎn)過程中，通過改變生產(chǎn)對(duì)象的形狀、相互位置和性質(zhì)等，使其成為成品或半成品的過程。機(jī)械產(chǎn)品的工藝過程又

6、可分為鑄造、鍛造、沖壓、焊接、機(jī)械加工、熱處理、裝配、涂裝等工藝過程。其中與原材料變?yōu)槌善分苯佑嘘P(guān)的過程，稱為直接生產(chǎn)過程，是生產(chǎn)過程的主要部分。而與原材料變?yōu)楫a(chǎn)品間接有關(guān)的過程，如生產(chǎn)準(zhǔn)備、運(yùn)輸、保管、機(jī)床與工藝裝備的維修等，稱為輔助生產(chǎn)。由于零件加工表面的多樣性、生產(chǎn)設(shè)備和加工手段的加工范圍的局限性、零件精度要求及產(chǎn)量的不同，通常零件的加工過程是由若干個(gè)順次排列的工序組成的。工序是加工過程的基本組成單元。每一個(gè)工序又可括哪些工序，由被加工零件的復(fù)雜程度、加工精度要求及其產(chǎn)量等因素決定。3.3表面加工方法的確定根據(jù)零件的幾何形狀、尺寸精度及位置精度等技術(shù)要求，以及加工方法所能達(dá)到的經(jīng)濟(jì)精度，

7、在生產(chǎn)綱領(lǐng)已確定的情況下,可以考慮采用萬能性機(jī)床配以專用工卡具,并盡量使工序集中來提高生產(chǎn)率。除此之外，還應(yīng)當(dāng)考慮經(jīng)濟(jì)效果，以便使生產(chǎn)成本盡量下降。查機(jī)械制造課程設(shè)計(jì)指導(dǎo)書10頁表1-6、1-7、1-8， 選擇零件的加工方法及工藝路線方案如下： 十字軸零件加工方案加 工項(xiàng) 目尺寸公差等級(jí)粗糙度加工方案?jìng)渥?25外 圓IT86.3粗車-半精車表1-6左 右端 面IT1012.5粗 車表1-6 25外 圓IT86.3粗車-半精車表1-8上 下端 面IT1012.5粗 車表1-7 23孔IT93.2鉆-鉸表1-7內(nèi)螺紋M8IT63.2攻螺紋表1-10 6孔IT1212.5鉆表1-7 8孔IT1212

8、.5鉆表1-73.4加工階段的劃分在粗加工階段。首先將精基準(zhǔn)準(zhǔn)備好，使后續(xù)工序都可以采用精基準(zhǔn)定位加工，保證其他加工表面的精度要求；首先25圓面作為粗基準(zhǔn)粗車右端面及25，然后以此圓軸線及端面為精基準(zhǔn)加工其他面和孔。在采用小彎板加工 另一部分，以保證其形位公差之要求。選用工序集中原則安排十字軸的加工工序。該零件的生產(chǎn)類型為大批生產(chǎn)，可3.5工序順序的安排機(jī)械加工工序（1）遵循“先基準(zhǔn)后其他”原則，首先加工基準(zhǔn)25外圓軸線及端面 。（2）遵循“先粗后精”原則，先安排粗加工工序，后安排精加工工序。（3）遵循“先主后次”原則，先加工主要表面（4）遵循“先面后孔”原則，先加工外圓面、端面，再加工孔，確

9、定工藝路3.6確定工藝路線工序號(hào)工序名稱機(jī)床裝備 工藝裝備10調(diào)度15熱處理20粗車四端面使長(zhǎng)度為109CA6240三抓卡盤、車刀、游標(biāo)卡尺25粗車四軸到26.5CA6240三抓卡盤、車刀、游標(biāo)卡尺30半精右車四軸到25.3CA6240三抓卡盤、車刀、游標(biāo)卡尺35鉆孔2360孔攻螺紋孔M8Z528專用夾具、鉆頭鉸刀、絲錐40鉆6、8孔Z3040專用夾具、鉆頭錐度鉸刀 45熱處理 50精磨四個(gè)軸到25、軸長(zhǎng)108M120三抓卡盤、砂輪、游標(biāo)卡尺55去毛刺60檢查入庫加工設(shè)備和工藝設(shè)備1 機(jī)床的選擇：采用CA6140普通車床、Z535立式鉆床、磨床2 選擇夾具：該零件的生產(chǎn)綱領(lǐng)為大批生產(chǎn)，所以采用

10、專用夾具。3 選擇量具：采用塞規(guī),雙用游標(biāo)卡尺。4機(jī)械加工余量、工序尺寸及公差的確定4、1工序1銑四軸端面1、工件材料:20CrMnTi，=1018Mpa，模鍛。機(jī)床：臥式車床CA6140刀具：YT15圓柱車刀，齒數(shù)Z=6，依據(jù)手冊(cè)，由切削深度，以及加工類型（不經(jīng)粗銑的半精銑），選用粗齒。2、計(jì)算切削用量根據(jù)刀具材料以及加工類型，依據(jù)機(jī)械工藝簡(jiǎn)明手冊(cè)查表=0.12mm，。采用硬質(zhì)合金圓柱車刀，=50mm，Z=6，則，由機(jī)床說明書取，于是。刀具每分鐘進(jìn)給量為=662.4mm/min.3、計(jì)算基本時(shí)間本工序?yàn)橄嗤乃膫€(gè)工步4、計(jì)算其他時(shí)間 t1=6%t=29.2s5、 單件時(shí)間計(jì)算 td=t+t1

11、=486.4s+29.2s=515.6s4、2工序2粗車四軸外圓1、加工條件機(jī)床：臥式車床C6140刀具：YT5外圓車刀，由于=1018Mpa，加工材料為結(jié)構(gòu)鋼，選用前角25，系統(tǒng)剛性足夠，切削深度不大應(yīng)選用較小主偏角，依據(jù)手冊(cè)主偏角范圍1015，由于取較小主偏角可以提高刀具壽命，因此選擇10，根據(jù)前角大小，以及加工類型（粗車），查的相應(yīng)的=8，刀桿尺寸為。2、計(jì)算切削用量根據(jù)加工尺寸確定背吃刀量為工件直徑靠近20mm，刀具材料為硬質(zhì)合金，背吃刀量0.6mm，有工藝手冊(cè)查表得，通過查表法確定切削速速，根據(jù)縱車外圓的切削速度表，并根據(jù)以上得出的切削標(biāo)準(zhǔn)，選出對(duì)應(yīng)的切削速度為，由機(jī)床說明書取轉(zhuǎn)速為

12、=相應(yīng)的轉(zhuǎn)速為3、計(jì)算基本時(shí)間本工序?yàn)樗膫€(gè)相同工步4、計(jì)算其他時(shí)間 t1=6%t=0.8s5、單件時(shí)間計(jì)算 td=t+t1=13.32s+0.8s=14.12s4、3工序3半精車四軸外圓1、 加工條件2、 機(jī)床：臥式車床CA6140刀具：YT15外圓車刀，由于=1018Mpa，加工材料為結(jié)構(gòu)鋼，查表得前角范圍1215，由于工件硬度低，前角需大一點(diǎn)，因此選用前角=15，刀桿尺寸為，刀尖半徑取。2、計(jì)算切削用量根據(jù)切削尺寸及加工要求。 按表面粗糙度選取切削用量：根據(jù)刀具的相關(guān)參數(shù)，并選擇有利于下步磨削最終達(dá)到最終的加工要求的表面粗糙度，查的進(jìn)給量為。用查表法確定切削速度，依據(jù)表加工工藝手冊(cè)表14-

13、13（硬質(zhì)合金外圓縱車削的切削速度）。，根據(jù)機(jī)床說明書，取，計(jì)算切削速度3、計(jì)算基本時(shí)間本工序?yàn)樗膫€(gè)相同工步基本時(shí)間4、計(jì)算其他時(shí)間 t1=6%t=0.5s 6、單件時(shí)間計(jì)算 td=t+t1=9s+0.5s=9.5s4、4工序4鉆孔，攻螺紋，锪錐面1、加工條件機(jī)床：立式鉆床Z518。刀具：6mm中心鉆；M8絲錐；60锪鉆。確定切削用量鉆孔由材料=1018Mpa0.748Gpa，查表取。依據(jù)鉆直徑以及進(jìn)給量查表確定，計(jì)算轉(zhuǎn)速，車床為無極轉(zhuǎn)速因此轉(zhuǎn)速不需修正。攻螺紋查表取，切削速度計(jì)算公式：查表確定各系數(shù)：，3、計(jì)算基本時(shí)間加工各步的走刀長(zhǎng)度、進(jìn)給量、轉(zhuǎn)速分別為4、計(jì)算其他時(shí)間 t1=6%t=0.

14、43s 5、單件時(shí)間計(jì)算 td=t+t1=7.11s+0.43s=7.54s4、5工序5鉆四軸向軸中心孔，锪錐面為了盡量保證6mm和8mm同軸，采用一次裝卡，連續(xù)加工的方法，這也有利于節(jié)約工時(shí)，提高生產(chǎn)效率，減小工人勞動(dòng)強(qiáng)度。先加工8mm的孔，后加工6mm的孔，這樣可以減小加工6mm孔的走刀距離和加工時(shí)受的阻力，從而減小加工誤差。由于這些孔的加工精度較低，因此只進(jìn)行粗加工就可以滿足要求，以下就對(duì)切削用量作具體的闡述。1、加工條件工件材料:20CrMnTi，=1018Mpa，模鍛。機(jī)床：臥式鉆床刀具：中心鉆8mm, ；20. 6mm，。 2、計(jì)算切削用量根據(jù)刀具材料以及加工類型，依據(jù)=1018M

15、pa0.748Gpa, ，由機(jī)械工藝簡(jiǎn)明手冊(cè)查表得加工8mm孔的進(jìn)給量以及切削速度分別為，計(jì)算得，查表的機(jī)床恰有此轉(zhuǎn)速。加工6mm孔的進(jìn)給量以及切削速度分別為，轉(zhuǎn)速計(jì)算結(jié)果與8mm為了簡(jiǎn)化加工過程采用與加工8mm孔一樣的轉(zhuǎn)速。3、計(jì)算基本時(shí)間加工各軸兩孔的走刀長(zhǎng)度、進(jìn)給量、轉(zhuǎn)速分別為4、計(jì)算其他時(shí)間 t1=6%t=5.8s 5、單件時(shí)間計(jì)算 td=t+t1=97.2s+5.8s=103s4、6工序6滲碳淬火滲碳深度嚴(yán)格控制為1.72.2，淬火硬度為HRC58604、7工序7精磨四軸外圓、端面1、加工條件機(jī)床：外圓磨床。磨輪：由表14-22（磨輪的選擇）確定砂輪材料為白剛玉，粒度為46，粘結(jié)劑為

16、陶瓷的平型砂輪，砂輪直徑d=250mm,厚度h=6mm。2、確定切削用量由加工要求。由于加工類型是直接精磨，且粗糙度為3、計(jì)算基本時(shí)間 t=70s4+62s4=528s 4、計(jì)算其他時(shí)間 t1=6%t=31.6s 5、單件時(shí)間計(jì)算 td=t+t1=528s+31.6s=559.6s5夾具設(shè)計(jì)5.1定位基準(zhǔn)的選擇以紙面為xoz軸，建立左手坐標(biāo)系；分析加工該工件需要的自由度：孔的直徑6：由刀具確定；孔的位置：需要限制沿X軸的平動(dòng)，沿Y軸的平動(dòng)兩個(gè)第一類自由度；孔與端部的垂直度：需要限制繞X的轉(zhuǎn)動(dòng)，繞Y軸的轉(zhuǎn)動(dòng)兩個(gè)第一類自由度；總共要限制：沿X軸的平動(dòng)，沿Y軸的平動(dòng)，繞X的轉(zhuǎn)動(dòng)，繞Y軸的轉(zhuǎn)動(dòng)四個(gè)第一

17、類自由度；因此，可讓工件的下端面為定位基面，8孔為另一定位基準(zhǔn)，對(duì)工件進(jìn)行定位加緊。5.2定位加緊方案1) 定位方案在下端面放置支承平面，可以限制沿Z軸的平動(dòng)，繞X的轉(zhuǎn)動(dòng)，繞Y軸的轉(zhuǎn)動(dòng)三個(gè)自由度；在底部8孔中加一短定位銷，可以限制沿X軸的平動(dòng)，沿Y軸的平動(dòng)；這樣，總共限制了：沿X軸的平動(dòng)，沿Y軸的平動(dòng)，沿Z軸的平動(dòng)，繞X的轉(zhuǎn)動(dòng)，繞Y軸的轉(zhuǎn)動(dòng)五個(gè)自由度；2) 夾緊方案通過兩個(gè)U型叉插在水平的兩個(gè)軸頸上，通過螺栓給工件一個(gè)向下的加緊力。同時(shí)，兩個(gè)U型叉插的連續(xù)使用，也使工件在繞Z軸的轉(zhuǎn)動(dòng)上受到限制。5.3 夾具元件的設(shè)計(jì)計(jì)算5.3.1夾緊力作用點(diǎn)如圖，由于加工的切削力向下，而支承平面會(huì)給工件一個(gè)向

18、上的力，為了使工件受力平衡，在工件的軸頸上，對(duì)稱的加上兩個(gè)作用力。5.3.2夾緊力的方向由于工件與支承平面的接觸僅靠重力維持，將導(dǎo)致工件在放置和加工的時(shí)候受力不穩(wěn)，因此，在工件的軸頸上，對(duì)稱的加上兩個(gè)向下的作用力，可使工件在Z方向上加緊。同時(shí)，兩個(gè)對(duì)稱的U型叉，又使工件在繞Z軸的轉(zhuǎn)動(dòng)上受到了一定的限制。5.3.3夾緊方案如圖，為工件的夾緊方案，兩個(gè)U型叉分別給軸頸兩個(gè)向下的力，與支承平面給工件的向上的力相平衡，起到了夾緊的作用。同時(shí)，如果刀具給工件繞Z軸的轉(zhuǎn)矩時(shí)，U型叉也能限制工件旋轉(zhuǎn)。5.4 夾具裝配圖的繪制這是零件的總裝配圖5.5 夾具體主要零件圖的繪制這是夾具體。這是鉆套支承。這是U型叉

19、。CAD圖紙見附圖十字軸毛坯圖見附圖;十字軸零件圖見附圖；夾具體零件圖見附圖； 鉆6孔夾具裝配圖見附圖。6體會(huì)與展望 在課設(shè)一月的時(shí)間里，既要做科技創(chuàng)新，又要課程設(shè)計(jì)，還得兼顧招聘會(huì)。下發(fā)課題后，花了幾天的時(shí)間找零件、設(shè)計(jì)相應(yīng)夾具，在盡量少犯錯(cuò)誤的情況下，完成課設(shè)。里面不免出錯(cuò)，還請(qǐng)老師糾正。在這次課程設(shè)計(jì)中，我重點(diǎn)看了機(jī)械制造裝備，翻閱了夾具手冊(cè)，在鉆模和銑床夾具中選擇了前者，了解到其主要用于鉆床上鉆、擴(kuò)、鉸或攻螺紋。加工中心易引起振動(dòng)，因此夾具的受力元件要有足夠的強(qiáng)度和剛度，夾緊機(jī)構(gòu)所提供的夾緊力應(yīng)足夠大，并要求有較好的自鎖性能。在符合其設(shè)計(jì)要求的情況下，得到這套組合夾具。設(shè)計(jì)過程中翻閱了

20、設(shè)計(jì)手冊(cè)，在網(wǎng)上查找了十字軸相關(guān)資料，確定可以使用鉆孔專用夾具來加工中心孔。通過分析十字軸圖紙，確定工藝路線，花費(fèi)兩天，繪制了零件、夾具圖紙。 這次課設(shè)不僅復(fù)習(xí)了機(jī)械制圖的知識(shí)點(diǎn)、鞏固所學(xué)，鍛煉了我的手繪能力，還為接下來的畢業(yè)設(shè)計(jì)提供了經(jīng)驗(yàn)。感謝羅老師在百忙之中批閱我們的課程設(shè)計(jì)。7參考文獻(xiàn) 1趙家奇.機(jī)械制造工藝學(xué)課程設(shè)計(jì)指導(dǎo)書M.北京：機(jī)械工業(yè)出版社,2006.2曾志新,呂明.機(jī)械制造技術(shù)基礎(chǔ)M.湖北:武漢理工大學(xué)出版社,2001.3李益明.機(jī)械制造工藝設(shè)計(jì)簡(jiǎn)明手冊(cè)M.北京：機(jī)械工業(yè)出版社,1993.4肖詩綱.切削用量手冊(cè)M.北京：機(jī)械工業(yè)出版社,1993.5上海柴油機(jī)廠工藝設(shè)備研究所.金

21、屬切削機(jī)床夾具設(shè)計(jì)手冊(cè)M.北京：機(jī)械工業(yè)出版社，1987.6鐘日銘.Pro/ENGINEER野火版3.0完全實(shí)例導(dǎo)航M.北京：機(jī)械工業(yè)出版社，2006.7李凱嶺.機(jī)械制造技術(shù)基礎(chǔ)M.北京：科學(xué)出版社，2007.十字軸零件圖十字軸鉆孔專用夾具圖請(qǐng)您刪除一下內(nèi)容，O(_)O謝謝！Many people have the same mixed feelings when planning a trip during Golden Week. With heaps of time, the seven-day Chinese請(qǐng)您刪除一下內(nèi)容，O(_)O謝謝！National Day holiday c

22、ould 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,

23、 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

24、 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

25、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 Arx

26、an 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

27、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 g

28、orgeous 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

29、 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 i

30、s 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

31、 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. Shutterbug

32、s 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 drowne

33、d 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 itra

34、ins 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 Fest

35、ival, 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 t

36、he 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 sk

37、illed 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 f

38、orbidden. 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

39、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 acro

40、ss 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

41、 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

42、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 p

43、ray 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 moder

44、n 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

45、 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

46、 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

47、 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

48、 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, no

49、mads, and urban dwellers from China and India to the Mediterranean Sea during various periods of time. I met my dear hubby in 2009 the second year I was in my school and it was the first year when he came here. We became colleagues. And there was nothing special happening during that year. He was ju

50、st a kind and humble brother graduated from the same college as me. But we did not know each other till he became my colleague and his office desk was just in front of me. There was only a glass between us. So actually we could see each other when we both look up. But it is not the main reason that

51、really draws us close. How we become close to each other was something seems quite natural. We went out to play badminton with other colleagues and we sometimes chatted for a while. He is a man of few words but somehow sometimes will say something really humorous. Then one day, to my great surprise,

52、 I found a pot of beautiful flower on my desk. It was just the flower I had talked about with my colleague the other day, and I thought it was her who put the flower there. But the truth is not. It was the humble guy sitting in front of me. He just simply said ,”well, I caught sight of this flower a

53、nd thought that its beautiful and you may like it”. I wonder why I was moved because of these simple words and present. Maybe it is the sincerity and the true self that impress me. I thanked him and some colleagues walked past my desk would appreciate the beautiful flower and they noticed that somet

54、hing romance happened there. Then later on, there were some little surprises once in a while. Once, there was something wrong with my drawer and I had complained about it unconsciously. And he fixed it for me. Then the other day, he placed several pink diamond roses beside the flower with a piece of

55、 paper saying” I love you more than I can say! Diamond stands for marriage, rose stand for love. I hope you are mine, become my wife. You are the only girl who I really want to spend the rest of my life to stand by.” Although there were some grammar errors but I got what he meant. He meant so clear and so direct. And actually, I accepted him some days earlier. I was just waiting for him to break the ice. So finally, the common interests and the common understanding brought us together. Some people say the relationship an