发动机外文翻译汽车专业毕业设计

《发动机外文翻译汽车专业毕业设计》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

1、WuxiProfessionalCollegeofScienceandTechnology专业外文翻译材料系别南京机电学院专业汽车检测与维修技术班级学生姓名学号指导教师2010年4月目录第一部分专业外文翻译材料原文1第二部分专业外文翻译材料译文12参考文献21专业外文翻译材料原文EnginesCylinderBlockThecylinderblockisthelargestpastoftheengine.Itsuppersectioncarriesthecylindersandpistons.Normally,thelowersection

2、formsthecrankcase,andsupportsthecrankshaft.ltcanbecastinonepiecefromgreyiron.Oritcanbealloyedwithothermetalslikenickelorchromium.Theironcastingprocessbeginsbymakinguptheshapesofwhatwillbecomewaterjacketsandcylindersassandcoreswhicharefittedintomoulds.Thestopstherepartsbeco

3、mingsolidironduringcasting.Moltenironispouredintosandmouldsthatareformedbypatternsintheshapeoftheblock.Aftercasting,coresandisremovedthroughholesinthesidesandendsjeavingspacesforthecoolingandlubricantpassages.Thereholesaresealedwithplugs.Thecastingisthenmachined.Cylindersa

4、reboredandfinished,surfacessmoothed,holesdrilledandthreadscut.Allcylinderblocksaremadewithribs,webandfilletstoproviderigiditybutalsokeepweighttoaminimum.CylinderBlockConstructionAsmoremanufacturerstrytomakevehicleslighterandmorefuelefficient,moreandmoreengineblocksarebeing

5、castfromaluminium.Ablockmadeofaluminiumalloyislighterthanifitweremadeofcastiron.Soiftwoenginesaregeneratingthesamepower,thealloyversionwouldhaveabetterweight-to-powerratiothanthecastalloyversion-Aluminiumalloyblocksaremadebyvariouscastingprocessesjncludingpressurecasting.A

6、nothermethodisgravitycasting,wherethemoltenmetalispouredintomolds.Castironlinersareusuallyusedinthecylindersofaluminiumblocks^andsometimesincast-ironblocks.Somesleevesarecastintotheblock.Groovesontheoutsideformakeythatstopsanymovementinthecylinder.Theyalsoincreasesurfacear

7、eatoassistheattransferfromthesleevetotheblock・Someblocksdon'tneedliners.Theycanbemadeofwearresistantmaterialthatmakesahard-wearingsurfaceforthepistonsandpistonrings.Orthecylinderboremayhavesomesortofsurfacetreatmenttomakeithard-wearing・Whenthecylinders,blockandcrankcaseare

8、allcasttogether,itiscalledamonoblockconstruction.Ahorizontally-opposedblockhasasplitcrank