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高等教育自学考试本科毕业论文变速箱体加工工艺及夹具设计考生姓名：准考证号：5专业层次：本科院（系）机械与动力工程指导教师：职称：讲师重庆科技学院二O一二年一月十五日高等教育自学考试本科毕业论文变速箱体加工工艺及夹具设计考生姓名：准考证号：专业层次：指导教师：院（系）：机械与动力工程重庆科技学院二O一二年一月十五日重庆科技学院高等教育自学考试本科毕业论文中文摘要I摘要在生产过程中，使生产对象（原材料，毛坯，零件或总成等）的质和量的状态发生直接变化的过程叫工艺过程，如毛坯制造，机械加工，热处理，装配等都称之为工艺过程。在制定工艺过程中，要确定各工序的安装工位和该工序需要的工步，加工该工序的机车及机床的进给量，切削深度，主轴转速和切削速度，该工序的夹具，刀具及量具，还有走刀次数和走刀长度，最后计算该工序的基本时间，辅助时间和工作地服务时间。变速箱主要是加工表面和轴孔，此外轴孔加工不但要达到孔本身的尺寸精度要求，还要保证与其他轴孔的相互位置精度。另外变速箱体里还装有轴承、齿轮、差速器等组件，这些零件盒组件的装配精度在很大程度上取决于箱体本身的精度。箱体的加工质量还会影响到传动性。夹具是机床的重要组成部件是根据机床的工艺和结构方案的具体要求而设计的。它是用于实现被加工零件的准确定位，夹压，刀具的导向，以及装卸工件时限位等等作用的。车床夹具一般都是在悬臂状态下工作的，为保证加工过程的稳定性；夹具结构应力求简单紧凑，轻便且安全，悬伸长度尽量小，使重心靠近主轴前支承。为保证安全，夹具体应制成圆形，加具体上的各元件不允许伸出夹具体直径之外。此外，夹具的结构还应便于工件的安装、测量和切屑的顺利排出或清理。关键词：工序，工位，工步，加工余量，定位方案，夹紧力，稳定性，安装，排出，清理，轴孔，精度重庆科技学院等高教育自学考试本科毕业论文英文摘要IIABSTRACTEnableproducingthetargetinprocessofproduction(rawmaterials,theblank,stateofqualityandquantityonpartbecomealways)takeplacedirectcourseofchangeaskcraftcourse,iftheblankismade,machining,heattreatment,assembleetc.andcallitthecraftcourse.Inthecourseofmakingthecraft,isitconfirmeveryerectorlocationandworkerstepthatprocessneedthisofprocesstowant,thelocomotiveofprocessing,thisprocess,andtheenteringthegivingamountofthelathe,cutdepth,therotationalspeedofthemainshaftandspeedofcutting,thejigofthisprocess,thecutterandmeasuringtool,aonehundredsheetsofnumberoftimesstillleavesandaonehundredsheetsoflengthleaves,calculatebasictimeofthisprocess,auxiliarytimeandservicetimeofplaceofworkingfinally.Thegearboxisthemainprocessingsurfaceandtheshafthole,inadditiontheshaftholeprocessingmustnotonlyreachtheholeitselfdimensionprecisionrequirement,guaranteeandothershaftholepositionaccuracy.Inadditionthegearboxalsoprovidedwithbearings,gear,gearandothercomponents,thesecomponentsboxcomponentassemblyprecisiondependstoagreatextentontheaccuracyofthehousingitself.Theprocessingqualityofthetankwillaffectthetransmissionof.Thefixtureisanimportantpartofthemachineisbasedonthemachinetooltechnologyandstructureoftheprogramme'sspecificrequirementsanddesign.Itisusedfortheprocessingofpartsoftheaccuratepositioning,clamping,cuttingguide,aswellastheworkpiecehandlinglimitandsoonthefunctionof.Lathefixtureisgenerallyincantileverstatework,inordertoensurethestabilityofmachiningprocess;fixturestructureshouldbesimpleandcompactstructure,portability,safety,extendedlengthassmallaspossible,sothatthecenterofgravityisclosetothespindlefrontbearing.Toensuresafety,thejigbodyshouldbemadeintoacircular,withspecificoneachelementisnotallowedtoextendbeyondtheclampdiameter.Inaddition,thefixturestructureshouldalsofacilitateworkpieceinstallation,measurementandthechipissmoothlydrainedorcleaning.重庆科技学院等高教育自学考试本科毕业论文英文摘要IIIKeyword:Process,position,thestep,thesurplusofprocessing,positioning,clampingforce,stability,installation,removal,cleaning，theshafthole,precision重庆科技学院等高教育自学考试本科毕业论文目录IV目录中文摘要.................................................................I英文摘要.................................................................II1绪论...................................................................12零件工艺的分析.........................................................32.1零件的工艺分析.................................................................32.2确定毛坯的制造形式.............................................................32.3箱体零件的结构工艺性...........................................................33拟定箱体加工的工艺路线.................................................53.1定位基准的选择.................................................................53.1.1精基准的选择................................................................53.1.2基准的选择..................................................................53.2加工路线的拟定.................................................................54加工余量、工序尺寸及毛坯尺寸的确定.....................................94.1箱盖、箱体....................................................................94.1.1毛坯的外廓尺寸............................................................94.1.2主要平面加工的工序尺寸及加工余量...........................................94.1.3主要平面加工的工序尺寸及加工余量...........................................95确定切削用量及基本工时................................................105.1箱盖.........................................................................105.1.1粗铣顶面...................................................................105.1.2粗粗铣结合面...............................................................105.1.3磨分割面...................................................................115.1.4钻孔.......................................................................125.2机座.........................................................................155.2.1粗铣箱体下平面.............................................................155.2.2粗铣箱体分割面.............................................................165.2.3磨箱体分割面...............................................................165.2.4钻孔.......................................................................175.2.5钻孔.....................................................................205.2.6钻孔............................................