汽车前桥设计.doc

摘要
中国改革开放以来，在农村实行家庭联产承包责任制的改革，使农村的经济空前活跃。农村的货运量和人口流动量急剧增加，加快了运输机械化成为农村经济发展的迫切需要，随之小型载货汽车也就应运而生，而前桥作为汽车上一个重要的零部件，也显得尤为重要。前桥一般位于汽车的前部，也称转向桥或驾驶桥。是通过悬架与车架相连，用以承受地面与车架之间的垂直载荷外，还承受制动力和侧向力以及这些力构成的力矩，并保证转向轮作正确的运动。在汽车使用中，转向桥的受力情况比较复杂，因此应具有足够的强度。如何保证转向车轮的正确定位角度，转向桥有足够的刚度，使操纵轻便并减轻轮胎的磨耗、汽车能快速平稳的行驶，就是一个重要问题。于是就有了本课题的研究和设计。本文首先对汽车前桥的发展历史做了相关描述，然后小型载货汽车的特点及国内外的发展现状进行了相关的描述，详细分析了前桥的组成和各部件的作用，之后对转向前桥做了详细的设计计算，主要计算了前梁、转向节等在制动和侧滑两种工况下的工作应力。本次设计的绘图均由CAD绘图完成。
关键字：汽车;前桥;前梁;转向节

Abstract
TheimplementationofthereformofthehouseholdcontractresponsibilitysysteminruralChinasincethereformandopeningup,theruraleconomyismoreactivethanever.Thedramaticincreaseinthevolumeofcargoinruralareasandpopulationflows,speedupthetransportmechanizationbecomeanurgentneedforruraleconomicdevelopment,alsocameintobeingalongwithasmalltruck,thefrontaxleasanimportantvehicleparts,especiallyimportant.
Thefrontaxleisgenerallylocatedinfrontofthecar,alsoknownasthesteeringaxleordrivingbridge.Isconnectedtothesuspensionandtheframetowithstandtheverticalloadsbetweenthegroundandtheframe,butalsotowithstandthebrakingforceandlateralforceandtorqueoftheseforcesconstitutes,andensurethecorrectmovementofsteeringrotation.Theuseofthecar,thesteeringaxlebymorecomplexandthereforeshouldbeofsufficientstrength.Howtoensurethecorrectpositioningoftheangleofthesteeringwheel,steeringaxlehaveenoughstiffnesstomakethemanipulationoflightandreducetirewear,thecarcanbefastandsmoothdrivingisanimportantissue.Sotherewillbethesubjectofresearchanddesign.
Thispaperfirstdescribedthehistoryofthedevelopmentofthecarbeforethebridge,thenthecharacteristicsofthesmalltruckandthecurrentdevelopmentathomeandabroadaredescribedinthedetailedanalysisofthecompositionofthefrontaxleandtheroleofthevariouscomponentsofthesteeringbridgetodothedetaileddesigncalculations,themaincalculationofthefirstbeam,knuckleandotherconditionsofworkinbothbrakingandskiddingstress.ThedesignofthegraphicsarecompletedbytheCADdrawing.
Keywords:car;frontaxle;beamsteering;knuckle