货车制动系液压系统设计毕业论文.doc

目录前言···················································································································11制动系要求······························································································································62制动系的选择·························································································································92.1汽车总质量··································································································92.2轴荷分配和质心位置的计算·······································································92.3同步附着系数·····························································································122.4制动强度和附着系数利用率······································································152.4.1制动器最大制动力矩·································································································182.4.2制动器因数····················································································································182.4.4制动器主要零件的结构设计···················································································213制动器驱动机构的结构型式选择及设计计算····························································233.1制动驱动机构的结构型式选择···································································243.1.1液压制动驱动机构的设计计算··············································································253.2制动力分配的调节装置··············································································274液压系统计算及工作原理·············································································284.1汽车制动装置的工作原理··········································································284.2制动缸液压传动装置的工作原理·······························································284.3液压优点与缺点·························································································294.3.1液压优点························································································································29孙瑜：货车制动系液压系统设计24.3.2液压的缺点····················································································································294.4轮缸的计算································································································294.4.1前轮轮缸的活塞作用面积························································································294.4.2方向控制换向阀·····················································································314.4.3对换向阀的性能要求·································································································314.4.4换向阀用于以下目的·································································································314.4.5手动换向滑阀的结构和工作原理··········································································314.5压力控制阀································································································324.3.1对安全阀的性能要求·································································································324.3.2对稳压阀的性能要求·································································································325结论···········································································································································33致谢···············································································································································34参考文献·····································································································································35附录A···········································································································································36附录B···········································································································································42摘要汽车制动系是用以强制行驶中的汽车减速或停车、使下坡行驶的汽车保持稳定以及使已停车的在原地（包括在斜坡上）驻流不动的机构对制动器的效能、制动效能的恒定性。使驾驶员敢于发挥出汽车的高速行驶能力，从而提高汽车运输的生产率。制动时的方向稳定性有着具体的要求。随着高速公路的迅速发展和车速的提高以及车流密度的日益增大，为了保证行车的安全性，汽车制动系的工作可靠性显得日益重要，也只有制动性能良好、制动系工作可靠的汽车，才能充分发挥其动力性能。液压制动系统提高了汽车制动的安全性，增加了安全行驶性，研究液压制动系统是为了更好的保证汽车的行驶性能的可靠性，研究范围主要包括系统中各个部件的压力，流量，和功率，充分发挥制动性能。提高制动效率。减低流量的损失。关键词：制动效率制动系统流量功率AbstractTheautomobilebrakingsystemwasusestoforceinthetraveltheautomobiletodecelerateortheparking,tomakethedownhilltraveltheautomobiletomaintainstabilizesaswellascausestostopin-situin(includinginpitch)thestandingcurrentmotionlessorganizationtothebrakepotency,thebrakepotencyconstancy.。Causesthepilottodaretodisplaytheautomobilehighspeedtravelability,thusenhancesmotortransporttheproductivity.Timethebrakeyawingstabilityhastheconcreterequest。Increasedaybydayalongwiththehighwayrapiddevelopmentandthevehiclespeedenhancementaswellasthestreamofvehiclesdensity,inordertoguaranteethedrivingthesecurity,theautomobilebrakingsystemoperationalreliabilityappearsdaybydayimportantly,alsoonlythenbrakingqualitygood,brakingsystemworkreliableautomobile,candisplayitspowerperformancefully.。Thehydraulicbrakesystemenhancedthesecuritywhichtheautomobileappliesthebrake,increasedthesecurityofservice,theresearchhydraulicbrakesystemisforthebetterguaranteeautomobiledrivingqualityreliability,theresearchscopemainlyincludesinthesystemeachpartpressure,thecurrentcapacity,withthepower,displaysthebrakingqualityfully.Enhancesthebrakeefficiency.Decreasesthecurrentcapacitytheloss.Keyword:BrakeefficiencyBrakingsystemCurrentcapacityPower孙瑜：货车制动系液压系统设计4前言汽车自上个世纪末诞生以来，已经走过了风风雨雨的一百多年。从卡尔.本茨造出的第一辆三轮汽车以每小时18公里的速度，跑到现在，竟然诞生了从速度为零到加速到100公里/时只需要三秒钟多一点的超级跑车。这一百年，汽车发展的速度是如此惊人！同时，汽车工业也造就了多位巨人，他们一手创建了通用、福特、丰田、本田这样一些在各国经济中举足轻重的著名公司。让我们一起来回望这段历史，品味其中的辛酸与喜悦，体会汽车给我们带来的种种欢乐与梦想汽车同其它现代高级复杂工具如电子计算机等一样，并非是哪一个人坐在那里发明了的。发明之初的汽车也不是现在之个式样，如果你能见到当时的汽车，你也可能认为这不是汽车呢。汽车的发展也有一个漫长的历程，总的说来，汽车发展史可能分为蒸汽机发明前、蒸汽汽车的问世、大量流水生产汽车开始等三个阶段。1879年德国工程师卡尔.苯茨(KartBenz)，首次试验成功一台二冲程试验性发动机。1883年10月，他创立了“苯茨公司和莱茵煤气发动机厂”，1885年他在曼海姆制成了第一辆苯茨专利机动车，该车为三轮汽车，采用一台两冲程单缸0.9马力的汽油机，此车具备了现代汽车的一些基本特点，如火花点火、水冷循环、钢管车架、钢板弹簧悬架、后轮驱动前轮转向和制动手把等。与此同时在1893年就与威廉.迈巴特合作制成了第一台高速汽油试验性发动机的德国人戴姆勒(Daimler)又在迈巴特的协助下，又于1886年在巴特坎施塔特制成了世界上第一辆“无马之车”。该车是在买来的一辆四轮“美国马车”上装用他们制造的功率为1.1马力，转速为每分钟650转的发动机后，该车以每小时18公里的当时所谓“令人窒息”的速度从斯图加特驶向康斯塔特，世界上第一辆汽油发动机驱动的