Dynamic Analysis Of Wiper System And Noise Prediction Of Blade Reverse

Wiper noise generated in the wiping process is one of the main influence factors affecting the driving comfort. With the improving requirements of automobile comfort, wiper noise produced in the wiping process, especially the reversal process, has attracted widespread attention. Since the dynamic contact pressure of the contact between a blade and a windshield glass is difficult to be measured, it is also difficult to predict the degree of the wiper noise. In this paper, in the view of the reversal noise problem of a passenger-vehicle windscreen wiper system, the system dynamic models of the both wipers on the sides of the driver and copilot and the acoustic model composed of the windscreen glass and the vehicle cavity were built and the dynamic analysis and the Vibro-Acoustic response were computed. Then the factors affecting the reversal noise of the wipers were discussed and the improvements of the wipers were made. The main works are as follows:In order to simulate the bending deformation produced by the pressure between the blade and windshield, the blade was separated into a number of rigid beam sections along the length direction, which were connected by flexible connections. In order to simulate the torsional deformation of the blade, each beam segment is divided into two parts along the height direction, which were connected by the torsion spring and the revolute joint. The contacts were established between the windshield and the beam segments. Meanwhile, the rigid models including the output shaft, four-link mechanism and wiper arms were established. The pressure distributions and the reversal impact forces between the blades and the windscreen glass were analyzed under various working conditions, and the results were compared with the testing date.Applying the reversal impact forces resulted from the system dynamic simulation as the boundary condition, the acoustic model composed of the windscreen glass and the vehicle cavity was built and the Vibro-Acoustic response was computed. Thus, the sound pressure at the driver seat was predicted.On the basis of dynamic analysis and acoustic analysis of the wiper system, the factors affecting the reversal noise were discussed, and the improvement measures such as increasing the torsional stiffness of blades and modifying the location of fulcrums of wiper levers were adopted. The results of the improvements were compared with the original results, and the effects of the improvements were analyzed.