Research On The Speed Characteristics Of Long Downhill Heavy Duty Truck

With the continuous development of China’s transportation industry,heavy-duty trucks continue to enter every link of the transportation industry,but the number of heavy-duty trucks has a tendency to increase year by year,especially on long downhill sections,it is very easy Heavy and serious traffic accidents have caused significant losses to people’s lives and property,and seriously affected the safety of highway traffic.For the analysis of the causes of these accidents,in addition to the driver’s own reasons and road factors,when the heavy-duty truck is driving on a long downhill section,the brake failure due to excessive temperature rise of the brake has also become the main factor.Therefore,this paper studies the speed characteristics of heavy trucks driving on long downhill slopes.Based on the vehicle system dynamics theory,the principle of the temperature rise of the service brake system and the joint braking characteristics,a corresponding model is established,and the safety of the vehicle when driving downhill on long roads is analyzed through road experiments.The main research content of this article: introduce the structure and related principles of two engine continuous braking technologies,engine braking and exhaust braking,respectively,and analyze the change of engine exhaust braking torque with speed through the engine exhaust braking characteristic curve characteristic.The effects of vehicle running resistance,brake braking force and continuous braking force on the vehicle dynamics model are analyzed respectively,and the corresponding vehicle continuous braking dynamics model is constructed to obtain the vehicle continuous braking braking deceleration and braking distance and vehicle speed.Relationship.A model for heating and cooling the brake on a flat road is established,and a brake temperature rise model for driving on a slope is constructed based on this.Design the corresponding experiment and combine the long-downhill driving dynamics model and temperature rise model of the heavy-duty truck constructed before to conduct road tests in different gears for the engine brake and exhaust brake respectively.The relationship between torque and vehicle speed.Based on the G65 Baomao Expressway K49-K103 section,the longterm downhill driving characteristics of heavy-duty trucks were studied.The linear characteristics,load capacity,and driving speed were analyzed.Some typical long-downhill sections were selected as experimental sections.The calculation model of stable downhill distance and safe downhill distance,and make rational setting recommendations for the cargo load and driving speed limited by the current road section.This article provides technical guidance for the driving safety of heavy-duty trucks on long downhill driving,and has certain theoretical and practical value.