Multiphysics Coupling Analysis And Optimization Design Of The Boom Channel In Multi-way Valve For Excavators

Multi-way valve is the core control element of hydraulic system of construction machinery such as excavator.It has complex internal structure and diverse function types.At present,there is still a certain gap between the quality of domestic multi-way valve and foreign products.The disadvantages of domestic multi-way valve mainly lie in the problem of large pressure loss and high failure rate.There are few literatures on the comprehensive analysis of valve body fluid field,thermal field and structure field.Taking the excavator multi-way valve boom channel as the research object,the structure optimization of the excavator multi-way valve boom channel is carried out by using the fluid-thermal-structure multi-physical field coupling simulation analysis,orthogonal test analysis,BP neural network and genetic algorithm.The main research contents are as follows:Multi-physical field coupling simulation model of boom channel.Based on the geometric model of multi-way valve boom channel,a fluid-thermal-structure field coupling simulation system is established,and the boundary conditions of fluid field,thermal field and structure field are set according to the actual working conditions.The correctness of the simulation model is proved by grid independence verification.Simulation analysis of fluid-thermal-structure field coupling of boom channel.The simulation results of fluid field,thermal field and structure field are analyzed,and the structural parameters and target parameters of multi-way valve that need to be optimized are clarified.Orthogonal tests are designed according to the selected structural parameters and target parameters,and the orthogonal test results are intuitively analyzed and the hierarchical analysis is carried out,and then the pairwise combination of structural parameters is used as the influencing factors to analyze the interaction of target parameters.Multi-objective cooperative optimization design of boom channel.Using the orthogonal test table as the database,BP neural network combined with genetic algorithm optimization program is used to optimize the structural parameters of the multi-way valve boom channel through the optimization of the target parameters.The pressure difference between inlet and outlet of oil area was reduced by 8.89%,the pressure difference between inlet and outlet of oil area was reduced by 0.79%,the maximum temperature of valve body was reduced by 7.34%,and the maximum deformation of valve body was reduced by31.60%.The maximum stress of valve body is reduced by 6.81%.Experimental study on boom channel test.The multi-way valve test bench is used to test some target parameters of the multi-way valve boom channel.Through the test,the error of the pressure difference between inlet and outlet of the optimized oil inlet is 6.2%,the error of the pressure difference between inlet and outlet of the oil return area is 7.4%,and the maximum temperature error of the valve body is 5.1%.