| Because of the loader get the feature that operating speed, easy operation and high security, it has become an indispensable engineering machinery in the process of earthwork construction, the working efficiency of loader is directly related to the construction efficiency and the cost of the whole project. Working device and hydraulic system are important components of loader that the analysis and research of which will be of great significance. In this paper, we take Xu Gong ZL50 G wheeled loader of Chang Lin group as the research object to analyze and optimize its working device and hydraulic system. The main contents of this paper are as follows:Firstly, the related coordinate system was built based on operation characteristics of working device and the mathematical model was gotten according to different working conditions. The numerical simulation was done by MATLAB, the movement curve of working device under different working conditions was drawn by using MATLAB, the displacement of hydraulic cylinders were calculated and the external load of working device was analyzed which can provide support for the further simulation analysis of the working device.Secondly, by using Pro/E software to establish a parametric model, and combining with Workbench ANSYS finite element analysis to explicit the distribution of the maximum stress. With the help of the function of Design Exploration, we analyzed the effects of different size parameters on the maximum stress and mass of the working device, then the structure parameters were optimized to find the best structural design size, achieving the goal of optimal design that reducing the maximum stress without the increasing of the mass, providing theoretical foundation and basis for the improvement of working device's performance and the optimization of structure.Thirdly, defects were found by analyzing the hydraulic system of ZL50 G loader and the hydraulic system was optimized by referring to steering- by- wire system. The related coordinate system was built based on characteristics of steering, the mathematical model about load steering system was founded. MATLAB software was used for data simulation, the steering motion trajectory and displacement of steering hydraulic cylinder were gotten by MATLAB, and the steering resistance in the steeringprocess was analyzed, providing parameter support for further hydraulic system simulation analysis.The last one, Taking advantage of AMEsim to modeling for the optimized hydraulic system, focusing on the modeling of multiple directional control valve,proportional pressure reducing valve and flow amplifying valve. According to the actual working condition, the optimized hydraulic system was simulated and analyzed,and getting the characteristic curve of the optimized hydraulic system, the superiority and feasibility were verified by analyzing the working characteristics of the optimized hydraulic system, and the foundation for the application of steering-by-wire system on the loader was laid. |
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