Optimal Design Of Dimensions And Performances Of Railcar Dumper’s Clamping Linkages

With the improvement of the port handling capacity, people pay more attention to dumping efficiency of bulk materials, the application of railway dumper greatly improves the efficiency. As a part of railcar dumper, clamping linkages play the role of holding railcar and keep it stable in the whole dumping process. Because of clamping linkages need to meet the requirement of movement, load and space at same time, traditional design methods such as the exact-point graphical method, geometric analytical method are difficult to achieve the design requirements. Based on the characteristics of railcar dumper’s work process, the design requirements are converted into constraints, while optimization method is used in this paper to synthesis clamping linkages.Focusing on the design process of clamping linkages, following work is contained in this paper:First of all, gravity load change of railcar and its goods is analysed and calculated. Based on the hypothesis that accumulated material has the distribution form of evenly and unbalanced, geometric method is used to calculated goods’gravity and barycenter location in any angle of the dumping process. Based on the results, the total gravity and barycenter location of railcar and its goods are calculated through method of centroid theorem, and the gravity load basis for the design of clamping linkages is provided.Secondly, The displacement equations are derived for both four-bar linkage and the six-bar linkage, and the displacement relations of linkages is obtained by solving these equations. The static equilibrium equations are also established for the linkages, and force analysis model is obtained. Besides, find out dangerous dumping angle by analysing characteristic of clamping force, and get conditions of safe dumping.Then, the mathematic model of the optimal design for the clamping linkages with counter-weights is set up, in which objective function is designated as minimum weight, and the conditions for safety and the work space are transformed as the constraint while the position coordinates of the fixed joints and the lengths of the linkages are taken as optimization variables. The mathematic model for the optimal design of the linkages is solved by MATLAB, and optimal solution which meets every constraint condition is obtained.Finally, the optimization result of linkage dimensions and counterweight are substituted into total displacement equations and static equilibrium equations, and the result is verified in three areas of motion, force and space. The numeral results are applied in the practice for the users.