Study On The Research Of Truck Jacobs Engine Brake

It has some limitations when the truck go downhill and only use one speed brake device.So it shouldcooperate the engine brake device and the hydraulic retarder.The heat generated by hydraulic retarder is almost completely dissipated by the cooling system.Because of the limited cooling capacity of cooling system,the hydraulic retarder would automatically shut down when the cooling power could not meet the cooling requirements of the hydraulic retarder.The ratio of the heat dissipated by the cooling system to the heat generated by the engine brake device has not been known yet.Through the actual road test,this paper obtain the ratio of the cooling system heat dissipation to the braking force of the vehicle when the vehicle only uses the engine brake device.Through the proving ground test,this paper obtains the brake ability of the Jacobs engine brake system and the downhill stable speed in different gear and slope and discusses the proper transmission gear when the truck uses Jacobs engine brake system.Through the road test,this paper obtain the ratio of the heat dissipating capacity to the braking force of the vehicle when Delong F2000 dump truck goes downhill and uses the Jacobs engine braking system.By comparing with the downhill road test when the truck does not use the Jacobs engine braking system,it obtains the differences of the average downhill speed,the use times of brake pedals and the value of temperature change of hub before and after the downhill experiments.This paper gives a detailed description of the vehicle preparations,vehicle proving ground test,vehicle road test,test data processing and analysis,and gives a simple introduction of the problems which should be noticed in the research.This paper has practical reference value for the truck proving ground test and road test.It provides a reference for the heat balance of the cooling system in the long downhill truck experiments.