曲軸工藝及夾具設(shè)計

1、I摘要曲軸是發(fā)動機中承受沖擊載荷、傳遞動力的重要零件，在發(fā)動機五大件中最難以保證加工質(zhì)量。其材料是由碳素結(jié)構(gòu)鋼或球墨鑄鐵制成的，由于曲軸工作條件惡劣，因此對曲軸材質(zhì)以及毛坯加工技術(shù)、精度、表面粗糙度、熱處理和表面強化、動平衡等要求都十分嚴格。如果其中任何一個環(huán)節(jié)質(zhì)量沒有得到保證，則可嚴重影響曲軸的使用壽命和整機的可靠性。曲軸有兩個重要部位：軸徑，拐徑，（還有其他）。軸徑被安裝在缸體上，拐徑與連桿大頭孔連接，連桿小頭孔與汽缸活塞連接，是一

2、個典型的曲柄滑塊機構(gòu)。發(fā)動機工作過程就是，活塞經(jīng)過混合壓縮氣的燃爆，推動活塞做直線運動，并通過連桿將力傳給曲軸，由曲軸將直線運動轉(zhuǎn)變?yōu)樾D(zhuǎn)運動。曲軸的旋轉(zhuǎn)是發(fā)動機的動力源。世界汽車工業(yè)發(fā)達國家對曲軸的加工十分重視，并不斷改進曲軸加工工藝。在曲軸零件的加工工藝過程中軸與軸中心線之間要有位置要求以毛坯軸兩端定位先加工兩中心孔以兩端中心孔定位再粗、精加工各軸的表面，然后以粗、精后的兩軸徑定位，采用專用夾具加工直油孔和銑鍵槽最后粗、精磨各軸。在

3、夾具的設(shè)計過程中，主要以V形塊和支承板來定位，靠直壓板和螺母來夾緊，鉆直油孔時應采用長型快換鉆套，銑鍵槽時采用立式銑床，曲軸小頭處應安裝一個對刀塊，夾具設(shè)計要方便、簡單。關(guān)鍵詞：關(guān)鍵詞：曲軸；加工工藝；專用夾具；中心孔；對刀塊IIIAbstractEnginecrankshaftissubjecttoimpactloadtransmissionpoweroftheimptantpartsthefivepiecesintheenginea

4、rethemostdifficulttoensurequalityprocessing.Itsmaterialisfromthecarbonstructurewhichmadeofsteelductileironasaresultofthepowkingconditionsthecrankshafttheroughmaterialprocessingtechnologyprecisionsurfaceroughnessheattreat

5、mentsurfacehardeningdynamicbalancingrequirementsareverystringent.Ifanyofthesearenotapartofqualityassurancethatcanbeseriouslyaffectedthelifeofthecrankshaftmachinereliability.Therearetwoimptantpartsofthecrankshaft:shaftdia

6、meterPoDrive(others).ShafthasbeeninstalledinthecylinderblockthePoDriveconnectingrodbigholeconnectingrodcylinderheadpistonconnectingholeisatypicalslidercrankmechanism.EnginewkingprocessisthatthePistonsaftertheblastingcomp

7、ressedgasmixturetopromotethepistontodolinearmotionfcethroughtheconnectingrodtothecrankshaftwillbefromthecrankshafttolinearmotionintorotarymovement.Therotationofthecrankshaftistheenginepowersource.Thewldautomobileindustry

8、indevelopedcountriesareattachgreatimptancetoimprovetheprocessingcrankshaftcrankshaftprocessingtechnology.Incrankshaftmachiningprocessbetweenthecentralaxiswiththeaxiscenterlineofthelocationoftherequirementshavetoberoughax

9、ispositioningprocessingatbothendsofthetwocentralholetocenterholelocationonbothendsthenroughfinishingthesurfaceoftheshaftthentocruderefinedofthetwoshaftafterpositioningtheuseofdedicatedprocessingfixturestraightholethefina

10、lroughkeywaymillinggrindingoftheshaft.InthefixturedesignprocessmainlyVshapedblockbearingplatestolocatebydirectplatenuttoclampdrillholeshouldbedirectlyusedfdrillinglongsetoffastusedverticalmillingkeywaymillingcrankshafthe