【作者】 段军峰；

【导师】 余强；

【作者基本信息】 长安大学 ， 车辆工程， 2011， 硕士

【摘要】 随着我国经济的高速发展,道路运输业呈现高速发展趋势,然而繁荣的背后也隐藏着危机,即日益增长的道路安全事故,尤其是在长大下坡路段行驶的重型商用车,造成了严重的后果。重型车辆造成交通事故的一个重要原因是持续制动状态下行车制动器制动效能失效,因此为长大下坡行驶的重型车辆安装高效的持续制动装置成为解决这一问题的有效方案。本文对目前使用的几种持续制动装置的工作原理及工作过程进行了介绍,经过对各持续制动装置的比较得出,排气门制动装置是一种高效的持续制动装置。目前排气门制动装置在欧美发达国家已经得到了广泛的应用,并且取得了良好的效果。本文对其制动特性进行了细致深入的研究,,对发动机排气门制动装置的工作原理、工作过程以及使用工况进行了探讨。为研究排气门制动的效果,进行了排气门制动平路实验,并对实验结果进行了分析计算,得到了持续制动性能的量化结果,并对发动机的制动工况各参数进行了计算。通过理论计算建立了汽车长大下坡的力学模型,研究了汽车以稳定车速下坡时的受力平衡,并进行了仿真计算。通过对实验数据进行推导计算,求得车辆在空载和满载状况下,车辆在使用不同挡位排气门制动时可以安全行驶的最大坡度与速度。本文对装有排气门制动装置的重型车辆连续长大下坡的安全行驶提供了理论依据,对重型车辆山区长大下坡的安全行驶具有重要的指导意义。更多还原

【Abstract】 As China’s economy develops fast, road transport of china also begins to grow quickly.At the same time there is a serious problem,more and more traffic accidents cause grievous consequence by heavy vehicles driving downhill especially.One main reason of the traffics made by heavy vehicle is that the efficiency of service brake slumps greatly,so it’s a valid proposal to install sustained braking system on heavy vehicle.This article studies the principle and working process of several sustained braking system.Compared with other sustained braking system, Exhaust valve Braking system(EVB) is a better sustained braking system. EVB system has been comprehensively used in developed countries and making good effects。This article researches characters of EVB precisely.This article studies the principle and working process of EVB and studies the usage of EVB.In order to study the results of EVB,we make a experiment of EVB on level road. Then we analyse the results of the experiment and get a statement of sustained braking. At the same time we calculate sevral parameters of engine.This article creats a mechanical model of heavy vehicle basing on theoretical arithmetic, and do a simulation of mechanical model. We study the mechanics equilibrium of heavy vehicle driving downhill at a constant speed and make a derivation of the results gotten before.At last we draw a conclusion,getting the speed of heavy vehicle driving downhill at different ratios of slope when the vehicle is no-live load or fully loadedThis article provides a thereunder for heavy vehicle with EVB system driving downhill.lt provides a guiding suggestion to improve the safety of heavy vehicle driving downhill.更多还原