摘要本设计是汽车变速箱箱体零件的加工工艺规程及一些工序的专用夹具设计。汽车变速箱箱体零件的主要加工表面是平面及孔系。一般来说，保证平面的加工精度要比保证孔系的加工精度容易。因此，本设计遵循先面后孔的原则。并将孔与平面的加工明确划分成粗加工和精加工阶段以保证孔系加工精度。基准选择以变速箱箱体的输入轴和输出轴的支承孔作为粗基准，以顶面与两个工艺孔作为精基准。主要加工工序安排是先以支承孔系定位加工出顶平面，再以顶平面与支承孔系定位加工出工艺孔。在后续工序中除个别工序外均用顶平面和工艺孔定位加工其他孔系与平面。支承孔系的加工采用的是坐标法镗孔。整个加工过程均选用组合机床。夹具选用专用夹具，夹紧方式多选用气动夹紧，夹紧可靠，机构可以不必自锁。因此生产效率较高。适用于大批量、流水线上加工。能够满足设计要求。关键词：变速箱；加工工艺；专用夹具AbstractThedesignisaboutthespecial-purposeclampingapparatusofthemachiningtechnologyprocessandsomeworkingproceduresofthecargearboxparts.Themainmachiningsurfaceofthecargearboxpartsistheplaneandaseriesofhole.Generallyspeaking,toguaranteetheworkingaccuracyoftheplaneiseasierthantoguaranteethehole’s.Sothedesignfollowstheprincipleofplanefirstandholesecond.Andinordertoguaranteetheworkingaccuracyoftheseriesofhole,themachiningoftheholeandtheplaneisclearlydividedintoroughmachiningstageandfinishmachiningstage.Thesupportingholeoftheinputbearingandoutputbearingisastheroughdatum.Andthetopareaandtwotechnologicalholesareasthefinishdatum.Themainprocessofmachiningtechnologyisthatfirst,theseriesofsupportingholefixandmachinethetopplane,andthenthetopplaneandtheseriesofsupportingholefixandmachinetechnologicalhole.Inthefollow-upworkingprocedure,allworkingproceduresexceptseveralspecialonesfixandmachineotherseriesofholeandplanebyusingthetopplaneandtechnologicalhole.Themachiningwayoftheseriesofsupportingholeistoboreholebycoordinate.Thecombinationmachinetoolandspecial-purposeclampingapparatusareusedinthewholemachiningprocess.Theclampingwayistoclampbypneumaticandisveryhelpful.Theinstructiondoesnothavetolockbyitself.Sotheproductefficiencyishigh.Itisapplicableformassworkingandmachininginassemblyline.Itcanmeetthedesignrequirements.Keywords:Gearbox;Machiningtechnology;Special-purposeclampingapparatus目录TOC\o"1-3"\h\z\uHYPERLINK\l"_Toc452544907"第一章绪论PAGEREF_Toc452544907\h1HYPERLINK\l"_Toc452544908"1.1当前发展现状PAGEREF_Toc452544908\h1HYPERLINK\l"_Toc452544909"1.2论文主要研究内容PAGEREF_Toc