Optimization Analysis Of Hydraulic Turnover Mechanism Of Heavy Truck Cab And Development Of Auxiliary Software

In recent years,domestic heavy truck has been developing rapidly,and various manufacturers are competing fiercely from vehicle performance,quality,cost,service,user experience and other aspects.As the launch time of automobile models is gradually shortened,The difficulty of design and development of heavy truck cab reversing system has increased geometrically,and the development cycle is shortened,the model variable is increased,and the program is more difficult,and the technical program has higher quality requirements.How to complete the design and verification of cab lift and turnover system of a new model in a shorter time has become the first challenge in the industry.At present,the cab of the heavy truck produced by most manufacturers is gradually flattened.In order to maintain and repair the engine,the cab needs to flip forward,and the weight of the heavy truck cab is too large,so the hydraulic flipping mechanism is selected for flipping work.Firstly,in view of the problem that the single optimization objective of the current heavy truck cab rollover mechanism cannot accurately measure whether the vehicle performance is improved or not,several evaluation parameters such as top output coefficient,oil pressure fluctuation coefficient and rollover capacity are selected for multi-objective optimization according to the actual working conditions during rollover.As the three parameters are affected by the same independent variables that vary in a certain range,it is taken as a constrained multi-objective problem for optimization analysis.The three evaluation parameters are weighted with different coefficients according to the needs of the enterprise,and the performance of the cab flipping mechanism is taken as the final evaluation index.The weighted coefficients of each parameter are determined by AHP,and the multi-objective optimization problem is solved in MATLAB software.Secondly,the reasons for the vibration and noise caused by the cab in the process of falling are analyzed.According to the oscillation duration and amplitude of the two aspects of optimization analysis,by changing the position of the upper and lower hinge points of the flipping mechanism to optimize the duration of the oscillation,by changing the maximum opening of the characteristic flow or the corresponding pressure drop,to indirectly change the size of the control valve port of the hydraulic control check valve,so as to reduce the amplitude of the oscillation when the cab falls back.The simulation model of heavy truck cab flipping system is built based on AMESim software,and the performance of the heavy truck cab flipping mechanism before and after optimization is analyzed,and the above optimization results are simulated and verified.Finally,in order to improve the efficiency of the design and development cycle of the hydraulic turnover system of the heavy truck cab and simplify its optimization steps,optimization software was developed based on Python language to assist the optimization work.Py Qt,Num Py and Sci Py are used to complete the corresponding function design in the aspects of software interface design,cab flipping process simulation and optimization function solving.Operation demonstration of software based on case analysis,The results show that the optimized performance of the hydraulic rollover system of the heavy truck cab is improved by 11.72% compared with that before optimization,which is similar to the simulation results.After optimization in the cab oscillation,the oscillation generated in the cab fall stage has different degrees of optimization in terms of the generation time and amplitude.The auxiliary software can display and run normally and obtain optimization results through optimization calculation.