PAGEII摘要四轮转向是指汽车的后轮也和前轮一样具有一定的转向功能，不仅可以与前轮同方向转向，也可以与前轮反方向转向。四轮转向汽车的环保性和节能性与现代汽车的设计理念相吻合，它适应汽车未来发展的趋势，存在广阔的发展前景。本文对液压式四轮转向系统进行了研究，主要工作如下：对课题进行了文献检索，查看了相关资料；对国内外四轮转向汽车的研究现状进行了详细的介绍，明确了设计的基本内容及需解决的主要问题；对四轮转向系统进行了分析，包括受力分析和运动学分析；设计了三种四轮转向汽车的转向液压系统方案，经过对比分析，选定其中一种作为最终的液压式四轮转向系统方案；确定该方案中液压系统的参数；对该方案中液压系统的液压缸进行设计和计算；对该方案中液压系统的液压元件进行选取。关键词：四轮转向；系统分析；液压系统；液压缸；液压元件ABSTRACTFour-wheelsteeringreferstotherearcarandhassomeofthesamefrontsteeringfunction,cannotonlywithfrontwheelsteering,alsocaninoppositedirectionwithfrontwheelsteering.Four-wheelsteeringtheenvironmentprotectionandenergyconservationcarwithmoderncardesignideacoincide,ittoadapttoautomobilefuturedevelopmenttrends,existingbroaddevelopmentprospects.Basedonthehydraulicfour-wheelsteeringsystemandmainworkisasfollows:Onissuesofliteratureretrieval,examinedtherelatedmaterial;Todomesticandinternationalresearchstatusoffour-wheelsteeringcarswereintroducedindetail,hasbeenclearaboutthedesignofthebasiccontentandthemainproblemsneedtobesolved;Forfour-wheelsteeringsystemisanalyzed,includingstressanalysisandkinematicsanalysis;Designthreefour-wheelsteeringautomobilesteeringhydraulicsystemscheme,throughcomparativeanalysis,selectoneasthefinalthehydraulicfour-wheelsteeringsystemsolution;Todeterminethisschemehydraulicsystemparameters;Forthisschemeofthehydrauliccylinderhydraulicsystemdesignandcalculation;Forthisschemeofthehydraulicsystemforselectinghydraulicelement.Keywords:Four-wheelsteering;Systemanalysis;Hydraulicsystem;Thehydrauliccylinder;Hydrauliccomponents目录TOC\o"1-4"\h\z\uHYPERLINK\l"_Toc264985913"摘要PAGEREF_Toc264985913\hIHYPERLINK\l"_Toc264985914"AbstractPAGEREF_Toc264985914\hIIHYPERLINK\l"_Toc264985915"第1章绪论PAGEREF_Toc264985915\h1HYPERLINK\l"_Toc264985915"1.1选题的背景及目的PAGEREF_Toc264985915\h1HYPERLINK\l"_Toc264985915"1.2国内外研究现状1HYPERLINK\l"_Toc264985915"1.3设计的基本内容5HYPERLINK\l"_Toc264985915"1.4设计解决的主要问题6HYPERLINK\l"_Toc264985915"第2章四轮转向汽车转向系统分析7HYPE