畢業(yè)設(shè)計（論文）萬向節(jié)滑動叉工藝設(shè)計

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1、南通職業(yè)大學畢業(yè)設(shè)計 萬向滑動叉工藝設(shè)計摘 要萬向節(jié)滑動叉位于傳動軸的端部。它的主要作用：一是傳遞扭矩，使汽車獲得前進的動力；二是當汽車后橋鋼板彈簧處在不同的狀態(tài)時，由本零件可以調(diào)整傳動軸的長短及其位置。零件的兩個叉頭部位上有兩個孔，用以安裝滾針軸承并與十字軸相連，起萬向聯(lián)軸節(jié)的作用。零件上的花鍵孔與傳動軸端部的花鍵軸相配合，用于傳遞動力之用。此次設(shè)計是在學完機械制造工藝學及機床夾具設(shè)計課程，并進行了生產(chǎn)實習的基礎(chǔ)上完成的。本設(shè)計主要編制該零件的機械加工工藝規(guī)程，并設(shè)計其中一道工序的專用夾具，并撰寫設(shè)計說明書。此次設(shè)計培養(yǎng)了我熟悉并運用有關(guān)手冊、規(guī)范、圖表等技術(shù)資料的能力。進一步鍛煉了我識圖、

2、制圖、運算、編寫技術(shù)文件和操作CAD等基本能力。關(guān)鍵字：萬向節(jié)滑動叉、工藝、專用夾具AbstractUniversal joint glide fork is located the drive shaft the nose.Its main function: One, the transmission torque, causes the automobile to obtain the advance the power; Two is when the automobile rear axle of car spring occupies the different condition

3、, may adjust the drive shaft by this components the length and the position. In the components two jaw spot has two holes, with installs the needle bearing and is connected with the cross axle, plays the rotary shaft coupling role. On the components colored key hole and the drive shaft nose spline s

4、haft coordinates, to use in transmitting using of the power.This design is in study the machine manufacture technology and the engine bed jig design curriculum, and carried on in the production practice foundation to complete. This design mainly establishes this components the machine-finishing tech

5、nological process, and designs working procedure the unit clamp, and composes the design instruction booklet.This design trained me to be familiar with and to utilize related technical data and so on the handbook, standard, graph abilities.Further exercised me to know the chart, the charting, the op

6、eration, the compilation technology document and operates CAD and so on the basic capability.Keyword: Universal joint glide fork, craft, unit clamp.31第一章零件的分析1零件的作用放牌汽車底盤傳動軸上的萬向節(jié)滑動叉，它位于傳動軸的端部。主要作用一是傳遞扭 矩，使汽車獲得前進的動力；二是當汽車后橋鋼板彈簧處在不同的狀態(tài)時，由本零件可以調(diào)整傳動軸的長短及其 位置。零件的兩個叉頭部位上有兩個39mm的孔，用以安裝該針軸承并與十字軸相連，起萬向聯(lián)軸節(jié)的作用

7、。零 件65mm外圓內(nèi)為50mm花鍵孔與傳動軸端部的花鍵軸相配合，用于傳遞動力之用。2零件的工藝分析萬向節(jié)滑動叉共有兩組加工表面，它們之間有一定的位置要求?，F(xiàn)分述如下：(1)以39mm孔為中心的加工表面這一組加工表面包括：兩個39mm的孔及其倒角，尺寸為118mm的與兩個孔39mm相垂直的平面，還有在平面上的四個M8螺孔。其中，主要加工表面為39mm的兩個孔。(2)以50mm花鍵孔為中心的加工表面 這一組加工表面包括：50mm十六齒方齒花鍵孔，55mm階梯孔，以及65mm的外圓表面和M60X16mm的外螺紋表面。 這兩組加工表面之間有著一定的位置要求，主要是： 1)50mm花鍵孔與39二孔中心

8、聯(lián)線的垂直度公差為100：0.2； 2)39mm二孔外端面對公39孔垂直度公差為0.1mm； 3)50花鍵槽寬中心線與39mm中心線偏轉(zhuǎn)角度公差為2。由以上分析可知，對于這兩組加工表面而言，可以先加工其中一組表面，然后借助于專用夾具加工另一組表面，并且保證它們之間的位置精度要求。第二章確定毛坯，畫毛坯-零件合圖1.確定毛坯的制造形式零件材料為45鋼。考慮到汽車在運行中要經(jīng)常加速及正、反向行駛，零件在工作過程中則經(jīng)常承受交變載荷及沖擊性載荷，因此應(yīng)該選用鍛件，以使金屬纖維盡量不被切斷，保證零件工作可靠。由于零件年產(chǎn)量為4000件，已達大批生產(chǎn)的水平，而且零件的輪廓尺寸不大，故可采用模鍛成型。這從

9、提高生產(chǎn)率、保證加工精度上考慮，也是應(yīng)該的。2.機械加工余量、工序尺寸及毛坯尺寸的確定 根據(jù)零件材料、硬度、毛坯重量及生產(chǎn)類型、鍛造方法等原始資料和加工工藝，分別確定各加工表面的機械加工余量、工序尺寸及毛坯尺寸。(1) 外圓表面(62mm及M60X1mm) 考慮其加工長度為90mm，與其聯(lián)結(jié)的非加工外圓表面直徑為65mm，為簡化模鍛毛坯的外形，現(xiàn)直接取其外圓表面直徑為65mm。62mm表面為自由尺寸公差，表面粗糙度值要求為Rz200m，只要求相加工，此時直徑余量2z3mm已能滿足加工要求。(2)外圓表面沿軸線長度方向的加工余量及公差(M60X1mm端面) 查機械制造工藝設(shè)計簡明手冊(以下簡稱工

10、藝手冊)表2.2l 4，其中鍛件重量為6kg，鍛件復雜形狀系數(shù)為S1，鍛件材質(zhì)系數(shù)取M1，鍛件輪廓尺寸(長度方向)180315mm。長度方向的余量查工藝手冊表2.22.5，其余量值規(guī)定為2.0一2.5mm，現(xiàn)取2.0mm。(3)兩內(nèi)孔毛坯為實心，不沖出孔。兩內(nèi)孔精度要求界于IT7一IT8之間，參照工藝手冊表2.3-9及表2.312確定工序尺寸及余量為： 鉆孔：25mm 鉆孔：37mm 2z12mm 擴鉆：38.7mm 2z1.7mm 精鏜；38.9mm 2Z0.2mm 細鏜：39mm 2z0.1mm(4)花鍵孔 要求花鍵孔為外徑定心，故采用拉削加工。參照工藝手冊表2.39確定孔的加工余量分配：

11、 鉆孔25mm 鉆孔41mm 擴鉆42mm 拉花鍵孔(1650mm*43mm*5mm) 花鍵孔要求外徑定心，拉削時的加工余量參照工藝手冊表2.319取2z1mm。(5)39mm 二孔外端面的加工余量（加工與量的計算長度為118mm） 1) 按照工藝手冊表2.225，取加工精度F2，鍛件復雜系數(shù)S3，鍛件重6kg，則二孔外端面的單邊加工余量為2.0一3.0mm，取Z2mm。鍛件的公差按工藝手冊表2.214，材質(zhì)系數(shù)取M1，復雜系數(shù)S3， 則鍛件的偏差。 2) 磨削余量：單邊0.2mm，(見二藝手冊表2.321)，磨削公差及零件公差一0.07mm。 3) 銑削余量：銑削的公稱余量(單邊)為：Z2.

12、0一0.21.8(mm) 銑削公差：現(xiàn)規(guī)定本工序(粗銑)的加工精度為ITll級，因此可知本工序的加工公差為-22M(入體方)。 由于毛坯及以后各道二序(或工步)的加工都有加工公差，因此所規(guī)定的加工余量其實只是名義上的加工余量。 實際上，加工余量有最大加工余量及最小加工余量之分。出于本設(shè)計規(guī)定的零件為大批生產(chǎn)，應(yīng)該采用調(diào)整法加工，因此在計算最大、最小加工余量時， 應(yīng)按調(diào)整法加工方式予以確定。 39mm二孔外端面尺寸加工余量和工序間余量及公差分布圖見圖7： 由圖可知：毛坯名義尺寸：118十22122(mm) 毛坯最大尺寸：122十1.32124.6(mm) 毛坯最小尺寸：1220.72120.6(

13、mm) 粗銑后最大尺寸：118十O.22118.4(mm) 粗銑后最小尺寸：118.40.22ll8.18(mm) 最后，將上述計算的工序間尺寸及公差整理成表3：第三章工藝規(guī)程設(shè)計1.基面的選擇基面選擇是工藝規(guī)程設(shè)計中的重要工作之一?；孢x擇得正確與合理，可以使加工質(zhì)量得到保證，生產(chǎn)率得以提高。否則，加工工藝過程中會問題百出，更有甚者，還會造成零件大批報廢，使生產(chǎn)無法正常進行。(1)粗基準的選擇 對于一般的軸類零件而言，以外圓作為粗基準是完全合理的。但對于本零件來說，如果以65mm外圓(或62mm外圓)表面作基準(四點定位)，則可能造成這一組內(nèi)外圓柱表面與零件的叉部外形不對稱。按照有關(guān)粗基準的

14、選擇原則(即當零件有不加工表面時，應(yīng)以這些不加工表面作粗基準；若零件有若干個不加工表面時，則應(yīng)以與加工表面要求相對位置精度較高的不加工表面作為粗基準)，現(xiàn)選取叉部兩個39mm孔的不加工外輪廓表面作為粗基準，利用一組共兩個短形塊支承這兩個39mm的外輪廓作主要定位面，以消除、四個自由度，再用一對自動定心的窄口卡爪，夾持在65mm外圓柱面上，用以消除、兩個自由度，達到完全定位。 (2)精基準的選擇 主要應(yīng)該考慮基準重合的問題。當設(shè)計基準與工序基準不重合時，應(yīng)該進行尺寸換算，這在以后還要專門計算 ，此處不再重復。2.制定工藝路線制訂工藝路線的出發(fā)點，應(yīng)當是使零件的幾何形狀、尺寸精度及位置精度等技術(shù)要

15、求能得到合理的保證。在生產(chǎn)綱領(lǐng)已確定為大批生產(chǎn)的條件下，可以考慮采用萬能性機床配以專用工夾具，并盡量使工序集中來提高生產(chǎn)率。除此以外，還應(yīng)當考慮經(jīng)濟效果，以便使生產(chǎn)成本盡量下降。(1)工藝路線方案一工序一：車外圓62mm，60mm，車螺紋M60X1mm；工序二：兩次鉆孔并擴鉆花鍵底孔43mm，淴沉頭孔55mm；工序三：倒角5X30；工序四：鉆Rc1/8底孔；工序五：拉花鍵孔；工序六：粗銑39mm二孔端面；工序七：精銑39mm二孔端面；工序八：鉆、擴、粗鉸、精鉸兩個39mm孔至圖樣尺寸并淴倒角2X45；工序九：鉆M8mm底孔6.7mm，倒角120；工序十：攻螺紋M8mm，Rc1/8；工序十一：沖

16、箭頭；工序十二：檢查。(2)工藝路線方案二工序一：粗銑39mm二孔端面；工序二：精銑39mm二孔端面；工序三：鉆39mm二孔；工序四：鏜39mm二孔；工序五：精鏜39mm二孔；工序六：車外圓62mm，60mm，車螺紋M60X1mm；工序七：鉆、鏜孔43mm，并淴沉頭孔55mm；工序八：倒角5X30；工序九：鉆Rc1/8底孔；工序十：拉花鍵孔。工序十一：鉆M8mm螺紋的底孔6.7mm孔，倒角120；工序十二：攻螺紋M8mm，Rc1/8；工序十三：沖箭頭；工序十四：檢查。上述兩個工藝方案的特點在于：方案一是先加工以花鍵孔為中心的一組表面，然后以此為基面加工39mm二孔，而方案二則與此相反，先是加工

17、39mm孔，然后再以此二孔為基準加工花鍵孔及其外表面。兩相比較可以看出，先加工花鍵孔后再以花鍵孔定位加工39二孔，這時的位置精度較易保證，并且定位及裝夾等都比較方便。但方案一中的工序八雖然代替了方案二中的工序三、四、五，減少了裝夾次數(shù)，但在一道工序中要完成這么多工作，除了選用專門設(shè)計的組合機床(但在成批生產(chǎn)時，在能保證加工精度的情況下，應(yīng)盡量不選用專用組合機床)外，只能選用轉(zhuǎn)塔車床，利用轉(zhuǎn)塔頭進行加工。而轉(zhuǎn)塔車床目前大多適用于粗加工，用來在此處加工39mm二孔是不合適的，因此決定將方案二中的工序三、四、五移入方案一，改為兩道工序加工。具體工藝過程如下：工序一：車外圓62mm，60mm，車螺紋M

18、60X1mm；工序二：兩次鉆孔并擴鉆花鍵底孔43mm，淴沉頭孔55mm，以62mm外圓為定位基準；工序三：倒角5X30；工序四：鉆Rc1/8底孔；工序五：拉花鍵孔；工序六：粗銑39mm二孔端面，以花鍵孔及其端面為基準；工序七：精銑39mm二孔端面；工序八：鉆孔兩次并擴孔39mm；工序九：精鏜并細鏜39mm二孔，倒角2X45；工序十：鉆M8mm底孔6.7mm，倒角120；工序十一：攻螺紋M8mm，Rc1/8；工序十二：沖箭頭；工序十三：檢查；以上加工方案大致看來還是合理的.但通過仔細考慮零件的技術(shù)要求以及可能采取的加工手段之后，就會發(fā)現(xiàn)仍有問題，主要表現(xiàn)在39mm兩個孔及其端面加工要求上。圖樣規(guī)

19、定39mm二孔中心線應(yīng)與55mm花鍵孔垂直，垂直度公差為100：0.2;39mm二孔與其外端面應(yīng)垂直，垂直度公差為0.1mm。由此可以看出；因為39mm二孔的中心線要求與花鍵孔中心線相垂直，因此，加工及測量39mm孔時應(yīng)以花鍵孔為基準。這樣做，能保證設(shè)計基準與工藝基 準相重合。在上述工藝路線制訂中也是這樣做了的。同理，39mm二孔與其外端面的垂直度(0.1mm)的技術(shù)要求在加工與測量時也應(yīng)遵循上述原則。但在已制訂的工藝路線中卻沒有這樣做：39mm孔加工時，以55mm花鍵孔定位(這是正確的)；而孔的外端面加工時，也是以55mm花鍵孔定位。這樣做，從裝夾上看似乎比較方便，但卻違反了基準重合的原則，

20、造成了不必要的基準不重合誤差。具體來說，當39mm二孔的外端面以花鍵孔為基準加工時，如果兩個端面與花鍵孔中心線已保證絕對平行的話(這是很難的)，那么由于39mm二孔中心線與花鍵孔仍有100：0.2的垂直度公差，則39mm孔與其外端面的垂直度誤差就會很大，甚至會造成超差而報廢。這就是由于基被不重合而造成的惡果。為了解決這個問題，原有的加工路線可仍大致保持不變，只是在39mm二孔加工完了以后，再增加一道工序以39mm孔為基準，磨39mm二孔外端面。這樣做，可以修正由于基準不重合造成的加工誤差，同時也照顧了原有的加工路線中裝夾較方便的特點。因此，最后的加工路線確定如下：工序一：車端面及外圓62mm，

21、60mm，車螺紋M60X1mm。以兩個叉耳外輪廓及65mm外圓為粗基準，選用C6201臥式車床并加專用夾具；工序二：鉆、擴花鍵底孔43mm，淴沉頭孔55mm，以62mm外圓為定位基準，選用c365L轉(zhuǎn)塔車床；工序三：內(nèi)花鍵孔5X30倒角。選用c620-1車床加專用夾具；工序四：鉆錐螺紋Rc1/8底孔。選用z525立式鉆床及專用鉆模。這里安排鉆Rcl8底孔主要是為了下道工序拉花鍵孔時為消除回轉(zhuǎn)自由度面設(shè)置的一個定位基準。本工序以花鍵內(nèi)底孔定位，并利用叉部外輪廓消除回轉(zhuǎn)自由度；工序五：拉花鍵孔。利用花鍵內(nèi)底孔。55mm端面及Rcl8錐螺紋底孔定位，選用L6120臥式拉床加工；工序六：粗銑39mm二

22、孔端面，以花鍵孔及其端面為基準。選用x63臥式銑床加工；工序七：鉆、擴39mm二孔及倒角。以花鍵孔及端面定位，選用z535立式鉆床加工；工序八：精鏜并細鏜39mm二孔。 選用T740型臥式金剛鏜床及專用夾具加工，以花鍵內(nèi)孔及其端面定位；工序九：磨39mm二孔端面，保證尺寸，以39mm孔及花鍵孔定位，選用M7l30平面磨床及專用夾具加工；工序十：鉆叉部四個M8mm螺紋底孔并倒角。選用z525立式鉆床及專用夾具加工，以花鍵孔及39mm孔定位；工序十一：攻螺紋4-M8mm，Rc1/8；工序十二：沖箭頭；工序十三：檢查。以上工藝過程詳見“機械加工工藝過程綜合卡片”4.確定切削用量及基本工時工序1：車削

23、端面、外圓及螺紋。本工序采用計算法確定切削用量；工序2：鉆、擴花鍵底孔43mm，及淴沉頭孔55mm，選用機床C365L；工序3：43mm內(nèi)孔50*30倒角，選用臥式車床C620-1。由于最后的切削寬度很大，故按成形車削制定進給量；工序4：鉆錐螺紋Rc1/8底孔(8.8mm)；工序5：拉花鍵孔；工序6：粗銑39mm二孔端面，保證尺寸；工序7：鉆、擴39mm二孔及倒角；工序8：精、細鏜38.9mm二孔，選用機床：T740金剛鏜床；工序9：磨39mm二孔端面，保證尺寸；工序10：鉆螺紋底孔4-6.7mm，并倒角120；工序11：攻螺紋4M8mm及Rc1/8。 需用到的典型夾具機構(gòu) 最后，將以上各工序

24、切削用量、工時定額的計算結(jié)果，連同其它加工數(shù)據(jù)，一并填入機械加工工藝過程綜合卡。 6.機械加工工藝過程綜合卡片（見附圖）第四章夾具設(shè)計1.問題的提出 本夾具主要用來粗銑39mm二孔的兩個端面，這兩個端面對39mm孔及花鍵孔都有一定的技術(shù)要求。但加工本道工序時，39mm孔尚未加工，而且這兩個端面在工序還要進行磨加工。因此，在本道工序加工時，主要應(yīng)考慮如何提高勞動生產(chǎn)率，降低勞動強度，面精度則不是主要問題。2.夾具設(shè)計(1)定位基準的選擇 由零件圖可知，39mm二孔端面應(yīng)對花鍵孔中心線有平行度及對稱度要求，其設(shè)計基準為花鍵孔中心線。為了使定位誤差為零，應(yīng)該選擇以花鍵孔定位的自動定心夾具。但這種自動

25、定心夾具在結(jié)構(gòu)上將過于復雜，因此這里只選用以花鍵孔為主要定位基面。 為了提高加工效率，現(xiàn)決定用兩把鑲齒三面刃銑刀對兩個孔端面同時進行加工。同時，為了縮短輔助時間，準備采用氣動夾緊。(2)切削力及夾緊力計算 刀具：高速鋼鑲齒三面刃銑刀， z20 (見切削手冊表3.28) 其中：Cr65050，a=3.1mm，x1.0，f=0.08mm，y0.72，a40mm(在加工面上側(cè)量的近似值)O.86，d=225mm，qO.86，w=0，z20所以 當用兩把刀銑削時，F(xiàn)2F2912(N) 水平分力：Fe1.1 F3203(N) 垂直分力：Fv=0.3F873(N) 在計算切削力時，必須把安全系數(shù)考慮在內(nèi)。

26、安全系數(shù)KK1K2K3K4。 （參見常用設(shè)計資料） 其中：K1為基本安全系數(shù)1.5； K2為加工性質(zhì)系數(shù)1.1； K3為刀具鈍化系數(shù)1.1； K4為斷續(xù)切削系數(shù)1.1。 所以F=KH1.51.11.11.13203=6395(N) 選用氣缸一斜楔夾緊機構(gòu)，楔角=10，其結(jié)構(gòu)形式選用w型，則擴力比i3.42。 為克服水平切削力，實際夾緊力N應(yīng)為： N(f1十f2)KH 所以 其中f1及f2為夾具定位面及夾緊面上的摩擦系數(shù)，f1=f20.25。則 氣缸選用100mm。當壓縮空氣單位壓力p0.5MPa時，氣缸推力為3900N。由于己知新楔機構(gòu)的擴力比i3.42，故由氣缸產(chǎn)生的實際夾緊力為 Nq390

27、0i39003.4213338(N) 此時Nq已大于所需的12790N的夾緊力，故本夾具可安全工作。3.定位誤差分析 (1)定位元件尺寸及公差的確定。夾具的主要定位元件為一花鍵軸，該定位花鍵軸的尺寸與公差現(xiàn)規(guī)定為與本零件在工作時與其相配花鍵軸的尺寸與公差相同，即16x43H1150H85H10mm。(2)零件圖樣規(guī)定50mm花鍵孔鍵槽寬中心線與39mm兩孔中心線轉(zhuǎn)角公差為2。由于39mm孔中心線應(yīng)與其外端面垂直，故要求39mm二孔端面之垂線應(yīng)與50mm。花鍵孔鍵槽寬中心線轉(zhuǎn)角公差為2。此項技術(shù)要求主要應(yīng)由花鍵槽寬配合中的側(cè)向間隙保證。 已知花鍵孔鍵槽寬為5mm，夾具中定位花鍵軸鍵寬為5mm，因

28、此當零件安裝在夾具中時，鍵槽處的最大側(cè)向間隙為： 0.048-(-0.065)=0.113(mm) 由此而引起的零件最大轉(zhuǎn)角為： 所以 =0.258 即最大側(cè)隙能滿足零件的精度要求。(3)計算39mm二孔外端面銑加工后與花鍵孔中心線的最大平行度誤差。 零件花鍵孔與定位心軸外徑的最大間隙為： 0.048-(-0.083)=0.131(mm) 當定位花鍵軸的長度取l00mm時，則由上述間隙引起的最大傾角為0.131100。此即為由于定位問題而引起的孔端面對花鍵孔中心線的最大平行度誤差。由于39mm孔外端面以后還要進行磨削加工，故上述平行度誤差值可以允許。4.夾具設(shè)計及操作的簡要說明 如前所述，在設(shè)

29、計夾具時，應(yīng)該注意提高勞動生產(chǎn)率。為此，應(yīng)首先著眼機動夾緊而不采用手動夾緊。因為這是提高勞動生產(chǎn)率的重要途徑。本道工序的銑床夾具就選擇了氣動夾緊方式。本工序由于是粗加工，切削力較大，為了夾緊工件，勢必要增大氣缸直徑，而這樣將使整個夾具過于龐大。因此，應(yīng)首先設(shè)法降低切削力。目前采取的措施有三：一是提高毛坯的制造精度，使最大切削深度降低，以降低切削力；二是選擇一種比較理想的斜楔夾緊機構(gòu)，盡量增加該夾緊機構(gòu)的擴力比，三是在可能的情況下，適當提高壓縮空氣的工作壓力(由0.4MPa增至0.5MPa)，以增加氣缸推力。結(jié)果，本夾具總的感覺還比較緊湊。夾具上裝有對刀塊，可使夾具在一批零件的加工之前很好地對刀

30、(與塞尺配合使用)；同時，夾具體底面上的一對定位鍵可使整個夾具在機床工作臺上有一正確的安裝位置，以利于銑削加工。5.銑床夾具的裝配圖及夾具體零件圖見附錄致 謝這篇畢業(yè)設(shè)計論文是我大學學習生活的小結(jié)，三年的大學生活將隨著論文的完成而告一段落。同時我也將開始新的工作和生活。通過三年的在校的理論學習和近三個月的在崗實習。再加上對畢業(yè)論文的編寫，我不僅對所學的專業(yè)課程有了全面和系統(tǒng)的了解和掌握，也初步懂得了完成一項設(shè)計的步驟、方法，為以后的繼續(xù)學習積累了寶貴的實踐經(jīng)驗。本課題是在指導老師季老師的親切關(guān)懷和悉心指導下完成的，季老師以淵博的學識和嚴謹?shù)闹螌W態(tài)度，為學生開闊了研究視野，豐富了專業(yè)知識。她謙遜

31、無私的高尚品質(zhì)和樸實真誠的做人準則，一絲不茍的敬業(yè)精神，對學生將是永遠的鞭策。在本課題的設(shè)計過程中，季老師在學習與生活中給予了熱情的幫助，付出了大量的心血，在此表示衷心的感謝。同時，感謝答辯組的評審老師們，感謝你們給我提出的寶貴意見和建議，你們的辛苦了！另外，非常感謝在我論文完成期間關(guān)心和幫助過我的同學、朋友們，是你們讓我的工作更順暢。還有要感謝的是我的父母，雖說平時您沒有說什么，但您的行動讓我知道在外不論是成功還是失敗，我都有一個避風的港灣。最后，我要感謝我的母校南通職業(yè)大學，是你給我了成長的空間，是你給了我夢想的舞臺，是你給了我騰飛的翅膀，在此預(yù)祝母校在今后的越辦越好！Common dif

32、ference and surface roughnessThe modern technology is more and more strict to the components sizeprecision request. Moreover, at present many components have spread ineach place different factory production, therefore must makes thestrict stipulation to these components sizes and the production,guar

33、anteed they have the interchangeability.Causes it for the components sign note size to change in a stipulationsector, guaranteed they have the interchangeable technology to becalled the common difference technology. Allows each size certainly tohave in the stipulation scope changes the momentum, is

34、called thecommon difference. For example, a components size may express for200.5, its common difference (size changes momentum) is 1.00mm.In does not affect the components performance in the situation, mustgive the size as far as possible big common difference, by falls theproduction cost to is lowe

35、st. The production cost reduces along withthe common difference elevates.Some three expressions size common difference way: Unidirectional,bidirectional and limit way. When uses the positive and negativecommon difference, adds to the common difference is been called thebasic size the theory size to

36、come up. When only allows the size tohave (or changes in a big way to the basic size sole direction, orchanges slightly) when change, is the unilateral tolerance. May(change in the size when the basic size two directions big or changesslightly) all may change, the common difference is bidirectional.

37、 Thecommon difference also may use the limit form to produce, theexpression components contour is biggest and most light-sized.Some and common difference related terminology and definition asfollows: Common difference: Upper limit and lower limit bad value stipulatedwhich for some size. Basic size:

38、The theory size, is calculates the extreme dimension andthe deviation outset size. Deviation The hole size or the axis size subtracts the basic sizeobtained bad value.The components biggest extreme dimension subtracts itsbasic size obtained bad value. The components smallest extreme dimension subtra

39、cts itsbasic size obtained bad value. Actual size: After processing components actual size. Coordination: Two assemble in between together components degree. May divide into the coordination three kinds: Gapcoordination, excessively full coordination, transition fit. Gap coordination: Two assemble i

40、n between the together fitting has thegap the coordination.Excessively full coordination: Two assemble in between the togethercomponents has the full coordinate - axis to be bigger than the hole,needs to make an effort the coordination which or the pressure carrieson, has is similar to two component

41、s welds in together effect. Transition fit: In two assembles in between the together components orexists excessively full, or has the gap the coordinate - axis to beallowed to be smaller than or to be bigger than the hole, but still instipulation common difference. Selective assembly: Through manual

42、ly tries to match chooses and theunit method. Through this method, may assemble common differencebigger components which makes under a lower cost. It may take the highmanufacture precision and is easy between the components onecompromise method which assembles. Uses the smallest hole size to take th

43、e computation commondifference and the processing remainder basic size. When uses thestandard the drill bit, the engine bed carries on theprecision processing to the hole,the system is extremelyeffective. Uses the smallest hole the size to take the basic size isbecause the hole size may change in a

44、big way through themachine-finishing, but cannot reduce.May defer to when the unusual high accuracy the standard sizeprovides, uses the basic shaft system is suitable. When computationcommon difference and remainder, uses the axis most large diameter totake the basic size. This is because the axis m

45、ay turn a smaller sizethrough the processing, but the basic size cannot increase. International common difference (IT) rank: A series of along withbasic size change, also provides the even precision in the stipulationrank the common difference. Altogether has 18 IT rank: IT01, IT0,IT1. IT16. Common

46、difference mark: The mark has produced the commondifference and the coordinate specification, the basic size is anumeral, behind and expresses the IT rank numeral with the expressionbasic deviation letter. They decide the tolerance zone together thesize and the position. The capital letter represent

47、s the hole thebasic deviation, the lowercase letter represents the axis the basicdeviation. Because the superficial appearance (namely fineness) canaffect the components the performance, therefore must preciselyperform to its size to stipulate, the superficial appearance is on thesuperficial differe

48、nce, including roughness, waviness, processingtexture direction and flaw. Roughness: Useful causes slightest which the work piece surface brightand clean processing craft creates surface irregularity. The surfaceroughness highly uses micron and the microinch carries on the survey. Waviness: Is surpa

49、sses roughness width the boundary big gap deviation,uses inch and a millimeter survey. May regard as roughness tosuperimpose on waviness surface surface irregularity. Processing texture direction: The superficial design directionwhich by which uses the processing method produces. Flaw: Not frequentl

50、y appears or the surface defect which can appear inthe very big sector talent, it including the crack, the blowhole, thetiny crack, delimits the mark and so on. The flaw influence usually isneglected in roughness levelling.The project pattern is makes the machine part the basis. Therefore, isengaged

51、 in the manufacturing industry the staff all want the correctunderstanding to apply to the entire production process patternmeaning. Must face this kind of fact in enterprise work engineer, namely anytwo machine part all cannot make the quite same not less than. He knewin the design must consider th

52、e repetition lives the small sizedifference which mid-production produces, in the pattern superscriptnote appropriate common difference, limits the size change in thepermission scope. After the processing components outline must belocated the common difference stipulation in the region. Uses thesuit

53、able common difference to be allowed to guarantee the product thefunction and the service life aspect all can achieve the anticipatedgoal.Each design personnel extremely are all clear, if the components allprocess the manufacture by a smaller common difference, then theproduct cost can rapidly incre

54、ase. Therefore, engineers unceasinglyobtain the advice, must use as far as possible the big commondifference. However, sometimes possibly appears between each kind ofcommon difference reciprocity which needs to the function request notto conduct the full research the situation. In this kind of situa

55、tion,in order to guarantee components when assembly does not give rise to aquestion or problem, not not appropriately designs the personnelusually to stipulate the common difference too strictly. Is oppositeearnestly to, is thorough carries on to the common difference analyzessaid that, this obvious

56、ly is a price expensive substitution way. If the product is produced by a lower price and the satisfiedmurderous intention request, stipulated the suitable processing commondifference is the most important work. The common difference size isby designs, it which the personnel determined is decided by

57、 many withthe design related condition as well as in the past when the designsimilar product obtains experience (if has this aspect experience). Ifstipulated the common difference too is small, when uses present theprocessing equipment processing work piece cannot achieve the designrequest, needs to

58、 design carries on the change. In the project pattern the place can cause many ischaotic and the economic loss. When drafts the common difference,designs the personnel to have fully to realize, must completelyachieve its design goal, in the pattern must contain the informationwhich needs. Thus, in t

59、he pattern must produce the completeinformation, and as far as possible simple was bright. In pattern eachpart all should be able to understand by everybody. In the patternexpressed the meaning regarding all uses it the personnel (design,purchase, cutting tool design, production, examination, assemb

60、ly andservice department) said all should be only. The common difference may select the different sign note method in thepattern. In the unidirectional system, a limit deviation is zero,another limit deviation is the size permission completely changes themomentum. In the bidirectional system in the

61、size sign note, uses theintermediate size and changes the momentum in its positive andnegative two directions to express. When when all sizes all occupy the material which the permissioncomponents includes for most limiting condition, called thiscomponents are at the biggest entity condition (MMC).

62、Regarding anaxis or external dimensions, its basic size for the biggest extremedimension, it changes when the tolerance zone, only can causeminification. Regarding a hole or the internal size, its basic sizefor the smallest extreme dimension, in the tolerance zone change, onlycan cause the size to i

63、ncrease.Each design personnel extremely are all clear, if the components allprocess the manufacture by a smaller common difference, then theproduct cost can rapidly increase. Therefore, engineers unceasinglyobtain the advice, must use as far as possible the big commondifference. However, sometimes possibly appears between e