Study On The Exhaust Brake Simulation And Experiment Of Heavy Commercial Vehicle

In recent years, with the development of economy, highway traffic volume increase rapidly, heavy commercial vehicle traffic accident rate has increased significantly. This phenomenon threatens people’s life safety and property safety. Especially on the long downhill, the driver must use foot brake frequently to reduce speed, which leads to brake overheating, and the brake efficiency quickly reduce until failure. In this case, it caused serious traffic accident. Vehicles equipped with auxiliary braking device can effectively prevent these accidents. For making a study of the different engine exhaust braking efficiency, this article carries on the corresponding simulation research.This paper based on the Innovation Fund Team Project of central universities——Heavy Commercial Vehicles Downhill Security Integrated Technical Research(NO.2013G322402), and introduces the engine exhaust brake structure, working principle, working process and the factors affecting the braking efficiency. Based on the analysis of engine exhaust braking process, we established the mathematical model of the engine exhaust brake. In order to analyze the factors influencing exhaust braking efficiency, we establish the simulation model. In addition, through the road test of a six axis cargo vehicle, we record the related data, and using the relations of speed and time finally conclude the relations of exhaust braking torque and engine speed. Doing the comparative study of the results between road test and simulation verified the accuracy and feasibility of the simulation model. Finally, based on force analysis of vehicle on the slopes, we derived related equation of downhill distance, gradient and speed. Research shows that engine exhaust brake used in specific road conditions can ensure the safety of the vehicle.In this paper, the simulation model of engine exhaust brake not only provides strong support for the research of different engine exhaust braking efficiency; as well as provides the technical guidance of heavy commercial vehicles operating mode on the continuous downhill road.