The Closing Energy Analysis And Structural Optimization Of The Vehicle Sliding Door

The sliding door system is a relatively independent and complex assembly in the commercial vehicle structure.It is the first vehicle system component to contact with the driver.Its opening and closing performance can reflect the vehicle quality at the first time of the user's contact.As the major automobile manufacturers pay more attention to the improvement of product details,the opening and closing performance of sliding door system has gradually become the focus of engineer.The optimization of its opening and closing performance has become one of the important fields in commercial vehicle research.This article aims at the problems of closing difficulty and vibration abnormality of sliding door system for a domestic brand commercial vehicle.By sliding door closing experiment and multi-body dynamics simulation,the main factors affecting the closing energy of the sliding door system are analyzed,and benchmarked with the closing experiments.The dynamic analysis and closed energy calculation of the sliding door system have been carried out using the CAE(Computer Aided Engineering)technology combined with the Fixed Interface Modal synthesis method(Craig-Bampton).An optimization scheme for the problems involved in the system is put forward,which solves the problem of excessive closing energy and abnormal noise.The main research contents and results of this paper are as follow:1.The multi-body dynamic models of the rigid-flexible coupled sliding door are built on the finite element analysis software HyperWorks and Multi-body dynamics analysis software ADAMS.The minimum closing energy of the sliding door system,the acceleration curve of the sliding door and the load of the main components are obtained by finite element analysis based on single variable principle.Moreover,the minimum closing energy is 5.65J,and the peak value of the sliding door acceleration curve is 0.065m/s2.However,the minimum closing energy is 5.43 J,and the peak value of the sliding door acceleration curve is 0.074m/s2,which are got from the closing performance test based on equivalent test principle.The error between the simulation result and the test result is within 15%,which proves that the multi-body dynamic model of the sliding door system can completely simulate the movement of the sliding door from a fully open position to a fully closed position.2.The effects of sliding door's components on the minimum closing energy of sliding door were analyzed by Virtual Prototype model.The results show that the weather-strip and the torsional spring are the main components that consume the closing energy.Their energy consumption accounts for 34.6%and 16.1%of total energy,respectively.In addition,the vibration and abnormal sound problems happen in the stopper and the door lock assembly,which are in agreement with the result of closing experiments.3.The weather-strip,stoppers,guide system and the door lock assembly are simulated based on the principle of single variable,which find that the problems of excessive compression displacement and unreasonable CLD curve exist in the sealant strip.The large stiffness and the excessive preload of the torsional spring in the guide system lead to excessive consumption of closing energy.The overload and uneven distribution of the stopper cause the sliding door to jitter along the direction of the vehicle length and abnormal sound.Due to the falling off of the door,the abnormal coordination between the lock pin and lock catch of the door lock system happens,which leads to large contact load and abnormal noise.4.The closing energy of the sliding door are optimized by decreasing the compression displacement of weather-strip,changing the section shape of the weather-strip to lower the slope of its CLD between 4 to 6 millimeter displacement range,decreasing the maximal torque and the preload of torsional spring,suitably reducing the fit clearance of stopper,and adjusting the position of lock pin in door lock assembly.The minimum closing energy of the sliding door system is reduced by 25%after optimization,and the effect is remarkable.