Reason Analysis And Simulation Investigation Of Shock Absorber Abnormal Noise

With the increased requirement to automobile's comfort, the research on controlling automobile vibration and noise has gradually attracted people's attention. Since main noise and vibration sources, for example the drive assembly, have been controlled to a great extent in recent years, the noise problems caused by other movement parts, which were ignored before, have gradually arisen. And abnormal noise of hydraulic shock absorber is most prominent among those problems.In this thesis, by means of synthesizing a number of technique materials home and abroad, the generation condition of MR7131A front shock absorber has been studied in detail. First the current research on abnormal noise, the measure methods, and the simulation research on shock absorber had been dissertated. Then based on structure and work theory of MR7131A front shock absorber, the character and reason of abnormal noise have been analyzed, and a result is proposed, that abnormal noise is caused by the clash vibration of shock absorber piston in the circulation process of promotion-condensation, and the abnormal noise can be categorized as four classes: abnormal noise of friction clash, abnormal noise of resonance, abnormal noise of flow cutting and abnormal noise of gas. And last the occurred position of abnormal shock, the relation between abnormal and vibration, and the generation and transfer way of abnormal noise have also been discussed.A three-dimensional finite element simulation model has been established based on the practice process of abnormal noise and finite element theory. And the result of simulation is reached. So found the theory base for abnormal noise research and the finally control for abnormal noise.At last, this thesis studies the abnormal noise experiment for MR7131A front shock absorber, and particularly introduces the experimental technical requirement, test instrument, test object, evaluation method of abnormal noise and the test results of typical products. Throng the comparison tests for strippable experimental products, this thesis separately discusses the correlation between abnormal noise generation and the values of valve rigidity, valve spring rigidity, oil performance and friction, and then, using experimental method, validates the correlation between structure parameter and reason of abnormal noise. Finally draw the research conclusions. So complete the reason analysis and simulation investigation of front shock absorber abnormal noise for...