Research Of A Automobile Disc Brake Noise

With the development of society,people's living standards are getting higher and higher,and the material and spiritual civilization is becoming more and more developed.Automobiles have become an indispensable part of most family life,not only as a walking tool.In addition,both foreign brands and independent brands of cars,people in the pursuit of power performance,fuel economy and safety at the same time,the car's comfort has a higher request.The noise generated by braking is also the focus of attention,market complaints and J.D.Power surveys show that the problem of brake noise is one of the most important issues for automobile users and one of the most frequently complained by customers.Therefore,automobile research and development institutions and manufacturers have to study the mechanism of brake noise prevention and simulation,test and design as a key research topic.According to the frequency value when brake noise is generated,brake noise can be low-frequency noise(10Hz~1k Hz)and medium-frequency noise(1k Hz~4k Hz)high-frequency noise(4k Hz~20k Hz).The generation of middle and high frequency brake noise is mainly affected by brake structure characteristics,environmental impact and friction material,of which friction material contributes the most.In the choice of friction material,not only to meet the braking distance(friction coefficient),long wear life,good stiction and other requirements,but also to meet the requirements of brake noise.Therefore,the research and application of friction materials is the foundation of the study of brake noise.Secondly,there is a certain difference between the bench test and the actual vehicle working condition,which is mainly reflected in the fact that the bench test cannot completely simulate the temperature and humidity of the real vehicle environment.Therefore,how to make the bench test as much as possible to simulate the real vehicle noise is also an important work for a long time.Thirdly,the low-frequency braking noise is related to the suspension structure.The equipment tested on the bench cannot detect the low-frequency braking noise due to its own vibration and precision of the sensor,so it is necessary to quickly detect the parts that contribute the most to the noise on the real vehicle,and find out effective solutions through the finite element analysis method.Based on the above consideration,this article,in the process of vehicle development to rear brake as the research object,starting with mature friction material,first by friction material primary test,reduce the risk of braking noise,and then through the bench test and real vehicle test,optimization of the high frequency noise and meanwhile improved braking noise bench test methods are improved.In view of the occurrence of low-frequency moan noise,the frequency characteristic and vibration of moan noise are tested through the data acquisition and analysis system,and the test data are compared and analyzed to find out the maximum vibration parts.Finally,the optimization direction is obtained through the finite element analysis,the model calibration and study of the test results.