Sound Analysis And Development Of Test Equipment For Vehicle Hydraulic Shock Absorber

With the continuous development of our automobile industry, the requirement to automobile's comfort and security has more increased. Shock absorber, as the main parts of suspension fork systems, whose quality directly affects the ride comfort and operating stability of a vehicle. Vibration and sound will be generated when shock absorber works to and fro because of its hydraulic tube structure that used in most modern vehicles. The performance of vehicle shock absorber is impaired by worse vibration and sound, sometimes the sound can be heard clearly by ears, which is called shock absorber abnormal sound. So the automobile quality and ride comfort is impaired heavy. Recently, the important significance of shock absorber sound is generally recognized At present, the shock absorber sound's mechanism is not very clear because of its complexity. Even to the same shock absorber whether it is normal or abnormal depend on different man. An impersonal method is cried for to test the vibration and sound of a shock absorber when the shock absorber sound is studied. But now there is no such a special test equipment at home, so this paper describes a set of test equipment that adapt to the practical need. In this thesis, by means of synthesizing a great number of materials and borrowing ideas from the advanced technique and experience home and abroad, the test equipment for vehicle hydraulic shock absorber sound is designed. First the feathers of vehicle hydraulic shock absorber vibration and sound is synthesized detailedly, and then based on road test and rig test, the data and its results are classified and analyzed. Shock absorber vibration shows various gaussianity under normal or abnormal sound. A new method of fault feature extracting for shock absorber vibration based on the selected bispectra . Based on these researches, a new test equipment for shock absorber sound is developed to meet the practical requirement which consists of shock absorber test stand, sensors and amplifier, LCD, embedded microcomputer and so on. At the same time, This paper discusses how to make the instrument small and light that adapt to road test. The test equipment for shock absorber sound has been used recently in the factory which can be applied in road test and in rig test. The results show that the test equipment is easy to use and can meet the practical requirement of testing vibration and sound for shock absorber. It is very useful for more understanding the mechanism of shock absorber abnormal sound and for its control.