内燃机连杆加工工艺及夹具设计论文[带图纸].doc

编号无锡太湖学院毕业设计（论文）题目内燃机连杆加工工艺及夹具设计信机系机械工程及自动化专业学号学生姓名指导教师（职称副教授）（职称）2013年5月25日无锡太湖学院本科毕业设计（论文）诚信承诺书本人郑重声明所呈交的毕业设计（论文）内燃机连杆加工工艺及夹具设计是本人在导师的指导下独立进行研究所取得的成果，其内容除了在毕业设计（论文）中特别加以标注引用，表示致谢的内容外，本毕业设计（论文）不包含任何其他个人、集体已发表或撰写的成果作品。班级机械91学号0923012作者姓名2013年5月25日III摘要连杆是内燃机的主要传动件之一，正文主要论述了连杆的加工工艺及夹具设计。连杆的尺寸精度、形状精度以及位置精度的要求都很高，而连杆的刚性比较差，容易产生变形，因此在安排工艺过程时需要把各主要表面的粗精加工工序分开。逐步减少连杆加工余量、切削力及内应力的作用，以及修正加工后的变形，最后就能达到连杆的技术要求。连杆的主要加工表面为大、小头孔和两端面，较重要的加工表面为连杆体和盖的结合面及连杆螺栓孔定位面，次要加工表面为大头两侧面及螺栓座面等。在连杆加工中有两个主要因素影响加工精度（1）连杆本身的刚度比较低，在外力（夹紧力、切削力）的作用下容易变形。（2）连杆是模锻件，孔的加工余量较大，切削时将产生较大的残余内应力，并引起内应力重新分布。通过对内燃机连杆的机械加工工艺及对粗加工大头孔夹具和铣结合面夹具的设计，主要归纳为以下两个方面第一方面连杆件外形较复杂，而刚性较差。其技术要求很高，所以适当的选择机械加工中的定位基准,是能否保证连杆技术要求的重要问题之一。在连杆的实际加工过程中，选用连杆的大小头端面及小头孔作为主要定位基面，同时选用大头孔两侧面作为一般定位基准。为保证小头孔尺寸精度和形状精度，可采用自为基准的加工原则保证大小头孔的中心距精度要求，可采用互为基准原则加工。第二方面关于夹具的设计方法及其步骤。关键词连杆变形加工工艺夹具设计IVABSTRACTTheconnectingrodisoneofthemaindrivingmediumofdieselengine,thistextexpoundsmainlythemachiningtechnologyandthedesignofclampingdeviceoftheconnectingrod.Theprecisionofsize,theprecisionofprofileandtheprecisionofposition,oftheconnectingrodisdemandedhighly,andtherigidityoftheconnectingrodisnotenough,easytodeform,soarrangingthecraftcourse,needtoseparatetheeachmainandsuperficialthickfinishmachiningprocess.Reducethemarginofprocessing,cuttingforceandinternalstressprogressively,revisethedeformationafterprocessing,canreachthespecificationrequirementforthepartfinally.IntheConnectingrodisoneofthemainprocessingsurfaceislarge,thesmallheadholeandbothendsofthemachinedsurface,isimportantfortheconnectingrodbodyandcoverjointsurfaceandtheconnectingrodboltholelocatingsurface,secondaryprocessingsurfaceforbearinglockinggrooves,oilhole,headandbodyandacoveronthetwosidesoftheboltseatsurface.Machineofconnectingrodaretwomajorfactorsthataffectthemachiningprecision1Connectingroditselfstiffnessisrelativelylow,intheexternalforcescuttingforce,clampingforceundertheactionofeasydeformation.2Connectingrodisdieforgings,holemachiningallowance,cuttingwillproducebiggerresidualstress,andstressredistributioncausedby.Theautomobileconnectingrodmachiningprocessandtheroughmachiningandmillingcombinedwithbigholeclampsurfacefixturedesign,mainlydividedintothefollowingtwoaspectsThefirstaspectconnectingrodpartswithcomplicatedshape,whilethepoorrigidity.Andtheveryhightechnicalrequirements,sotheappropriateselectionofmechanicalprocessinginthelocatingdatum,canensuretheconnectingrodisoneoftheimportantproblemsoftechnicalrequirements.Theconnectingrodinthepracticalproductionprocess,selectionofconnectingrodtothesizeoftheheadendandthesmallheadholeasthemainpositioningdatum,andchoiceofbigholetwosideasagenerallocatingdatum.Inordertoensurethesizeprecisionandshapeprecisionofthesmallheadhole,canbeusedforreferencefromtheprocessingprincipleensurethatthesizeofthefirstholecenterdistanceaccuracyrequirements,canbeusedforreferenceeachothertheprincipleofprocessing.Secondmainlyonthefixturedesignmethodandsteps.KeywordsConnectingrodDeformationProcessFixturedesign目录摘要...........................................................................................................................................IIIABSTRACT..................................................................................................................................IV目录............................................................................................................................................V1绪论.............................................................................................................................................11.1本课题的研究内容和意义...............................................................................................11.2国内外的发展概况...........................................................................................................11.3本课题应达到的要求.......................................................................................................32连杆的分析.................................................................................................................................42.1连杆的作用.......................................................................................................................42.2连杆的机械分析...............................................................................................................42.3连杆的结构特点...............................................................................................................42.4连杆的主要技术要求........................................................................................................52.4.1大、小头孔的尺寸精度、形状精度.....................................................................52.4.2大、小头孔轴心线在两个互相垂直方向的平行度.............................................52.4.3大、小头孔中心距.................................................................................................52.4.4连杆大头孔两端面对大头孔中心线的垂直度.....................................................52.4.5大、小头孔两端面的技术要求.............................................................................52.4.6有关结合面的技术要求.........................................................................................52.5连杆的材料和毛坯分析...................................................................................................53连杆的加工工艺规程的制定.....................................................................................................73.1加工工艺的基本概念.......................................................................................................73.2选择定位基准...................................................................................................................73.3确定加工余量...................................................................................................................83.4拟订机械加工工艺路线...................................................................................................83.5连杆工艺计算.................................................................................................................103.5.1粗铣两平面...........................................................................................................103.5.2粗磨两平面...........................................................................................................113.5.3钻小头小孔...........................................................................................................133.5.4粗镗小头孔...........................................................................................................143.5.5车大头外圆...........................................................................................................153.5.6粗镗大头孔...........................................................................................................173.5.7粗铣螺栓孔端平面...............................................................................................173.5.8精铣螺栓孔端平面...............................................................................................173.5.9铣开连杆大头.......................................................................................................183.5.10精铣体盖分开面.................................................................................................183.5.11钻扩铰螺栓孔.....................................................................................................183.5.12精磨体盖分开面.................................................................................................20