车辆长大下坡联合制动特性的研究论文.pdf

分类号:U27;U46 10710—20050129 媛步犬海硕士学位论文车辆长大下坡联合制动特性研究导师姓名职称申请学位级别论文提交日期学位授予单位惠鹏余强教授答辩委员会主席学位论文评阅人型星盘纠碰巧幽. 摘要汽车在山区长大下坡行驶过程中,仅采用主制动器持续制动是难以满足制动要求的。因此发动机制动、排气制动作为持续制动装置,对于在山区公路上使用的汽车是不可缺少的。本文对汽车下坡过程中发动机制动、排气制动与主制动器联合作用的制动特性进行了深入的研究。本文首先通过调研,确定了研究车型,并对研究车型进行了平路试验,得到了该车辆各档位发动机制动和排气制动的制动特性。其次,在发动机制动、排气制动制动特性分析的基础上,确定了它们的下坡能力和在下坡过程吸收能量的特点,得出下坡时仅使用辅助制动器制动也不能很好的满足制动要求。因此,对主制动器在下坡过程中温升与能量之间的关系模型进行了试验研究,分析了联合制动过程中辅助制动系统与主制动系统吸收能量之间的关系;进一步建立了联合制动时汽车下坡坡度、坡长和行驶车速与制动器之间的模型,并利用该关系模型对几种不同行驶工况的车辆在不同装载状态进行了模拟分析对比,得出了使用联合制动对于长大下坡汽车的主制动器制动效能恒定性有所提高。研究结果对于我国山区道路连续下坡行驶车辆安全行驶具有一定的实际指导意义。关键词:汽车长大下坡,主制动,辅助制动,联合作用 Abstract When vehicle travelsinthedownhill path mountain road,only use themain brake isnot meetrequirements inuous as acontinuous brake,it isindispensable for a vehicle travels inmountain area to use engine brake and exhaust thispaper,the authormake allin-depth study 011thebrake characteristics ofengine brake orexhaust brake withmainbrake affecttogetherwhen vehicle travelsinthe downhill road. First,the textidentifiedresearchmodet vehicles afterlotsofsurvey,then testthemodel vehicleson-road,and work outbrake characteristics ofvehicle engine brake and exhaust brake inevery ,based on theanalysis ofcharacteristics ofenginebrake and exhaust brake,the author determine their downhill capacity and theability ofenergy absorption characteristics,indicate mat only use assisted brake ishard tomeet brake requirements in downhill road,,by studying therelationship model between the temperature riseandenergy of themainbrake on thedownhill road,the author analysis the energy absorption relationship between mainbrakeand assistedbrake inthe course ofthe brake ,a relationship model on downhill slope,length andspeed with thebrakes Was setup when brake therelationship model,several different conditions on different loading ofvehiclesaresimulated,analysis pared,the resultisthatmainbrakebrakingperformance constant is