Study On Dynamic Performance Of Hydro-Pneumatic Suspension System For Mining Truck

Ride comfort and comfort of vehicles have relation to the vibration characteristics of vehicles,and the vibration characteristics of vehicles are dependent on the inherent characteristics of suspension. Therefore, the inherent characteristics of suspension determine ride comfort and comfort of vehicles directly.The inherent characteristics of suspension include the stiffness and damping characteristics mainly, which are all fixed in the traditional suspension. The natural frequency of vibration is due to sprung mass, therefore, ride comfort and comfort of vehicles with traditional suspension are poor. As a new type of suspension system,hydro-pneumatic suspension is based on oil as a delivery medium, with inert gas (usually nitrogen) as the elastic medium.With good non-linear stiffness and damping characteristics, it can guarantee the vehicles run smoothly during operation, reduce the incentive from the bumpy road, alleviate fatigue of drivers and also improve vehicle ride comfort and comfort. Therefore, the research of hydro-pneumatic suspension system performance is important for practical use.Comfort of mine truck is poor in actual use of the process, which is due to frequent damage to hydro-pneumatic suspension, which severely affects the efficiency of the workers. Based on the above problem, we take WC5 mine truck (non-rail rubber vehicles) as the research object to analysis dynamics performance of hydro-pneumatic suspension system to find out the root of the problems.Firstly, the corresponding structure is optimized,add check valves and damping hole to act as damping elements to alleviate vibration of mine truck from the uneven road;the mechanical valve is replaced with three-position and three-way reversing valve in order to eliminate mechanical wear and tear;to some extent,it improves the vehicle ride comfort and comfort,and also provides a basis for theoretical technology and references for optimization of structural parameters for hydro-pneumatic suspension,determines their structural parameters.Secondly,based on the theory of fluid dynamics and nonlinear vibration, we establish the non-linear mathematical model of hydro-pneumatic suspension system considering nonlinear stiffness, the dynamic friction between hydraulic piston and cylinder wall and accumulator structure parameters and so on.This research adopts hydraulic simulation software AMESim.We not only obtain structural parameters of hydro-pneumatic suspension which affect stiffness and damping characteristics through DOE simulation analysis, but also verify the correctness of the mathematical model.Different from the present stage of semi-active suspension, this research uses three-position and three-way reversing valve to reduce the vibration from the road through charge-discharge control of oil. Besides that,it improves the structure parameters after parameter optimization design, reduces the body's vertical acceleration and we also get the best stiffness characteristic curve.Swing frame is the main body carrying the weight of whole mine truck, whose structure is directly related to the life of mine truck. However, it's such a swing frame structure with few studies,so it's necessary to have a research for the stress and strain analysis and fatigue life prediction analysis.we establish three-dimensional solid model of swing frame using Pro/E, and make the stress and strain analysis through Patran.Besides,we also make some improvements to corresponding parts with the stress concentration.Fatigue life prediction analysis is carried on the swing frame before and after optimization, through which we achieve the result that the life of swing frame is extended to meet the requirements in actual use after optimization to some extent.Finally, we establish the space motion model of mine truck with the help of Pro/E,including hydro-pneumatic suspension cylinder, oriented institutions, frame,wheels and so on. Besides, some relevant simulation analysis is carried out using the software ADAMS,for exemple dynamics analysis of the mine truck,kinematic analysis, multi-rigid body dynamics simulation, climbing performance and roll performance research and so on. To some extent, it verifies the great improvement for overall performances of mine truck after optimization.