Parameters Design And Characteristics Analysis Of A Two-stage Pressure Hydro-pneumatic Suspension For Mining Dump Trucks

Mining dump trucks have the characteristics of high load capacity and severe driving conditions.Hydro-pneumatic suspension is widely used in construction vehicle such as mining dump trucks due to its nonlinear characteristics of stiffness and damping,which can adapt well to the change of external load excitation.However,the scalability of the hydro-pneumatic suspension will decrease under full load conditions,resulting in increased stiffness and poor ride comfort of mining dump trucks.In order to solve the stiffness of the hydro-pneumatic suspension is too high when the mining dump trucks is overloaded,this thesis designs a twostage pressure hydro-pneumatic suspension system based on the existing hydro-pneumatic suspension technology and conducts characteristic analysis and experimental research.The main research work includes:(1)The system structure and working principle of the two-stage pressure hydro-pneumatic suspension are analyzed,the internal structure parameters of the hydro-pneumatic suspension are designed based on the actual load requirements of the mining dump trucks.The influence of different parameters on the damping and stiffness characteristics of the two-stage pressure hydro-pneumatic suspension system is analyzed.The stiffness of single-chamber hydropneumatic suspension and two-stage pressure suspension system is compared.It shows that the two-stage pressure hydro-pneumatic suspension can reduce the vehicle stiffness by opening the high-pressure accumulator,can better protect the vehicle.(2)The 1/4 mining dump truck simulation model under random road excitation is built and the ride comfort is analyzed.By studying the three evaluation criteria that affect mining dump trucks ride comfort,the output characteristics of single-chamber hydro-pneumatic suspension and two-stage pressure hydro-pneumatic suspension are compared and analyzed.It shows that the vertical acceleration and tire vibration response of the two-stage pressure hydro-pneumatic suspension are significantly reduced,and the mining dump trucks ride comfort is improved.(3)The two-stage pressure hydro-pneumatic suspension model is built by AMESim It is found that the main factors affecting the output characteristics of the suspension include the structural parameters of the suspension itself and the working parameters of the suspension.The structural parameters of the suspension mainly include the diameter of the damping hole,the diameter of the check valve and the diameter of the piston rod.The working parameters of the suspension mainly include the driving speed,the loading mass and the initial inflation pressure and volume of the accumulator.By changing the working parameters under different working conditions and selecting different suspension structure parameters,the influence on the output characteristics of the suspension is studied.(4)The new two-stage pressure hydro-pneumatic suspension system is installed on the TLD110 mining dump truck,and the field test of suspension performance is carried out.The mining dump trucks performance under different working conditions is tested and analyzed.The correctness of the previous theoretical calculation and simulation analysis is verified by comparison test and simulation results.