Impact Analysis and Optimization of Material Parameters of Insulator on Brake Squeal

In this paper, factors that account for the disc brake noise were explored with a bench test to fix the methods of reducing the brake squeal noise. The influence of the stiffness and damping of insulator on the noise of the braking system was analyzed by establishing a mathematical model for the 6-DOF braking system with internal and external insulators. It is proposed that the insulator with a multilayered structure of different materials has a better restraining effect on brake squeal. Four different insulator schemes were designed, the test results of which were compared with those of the original scheme. The comparative analysis shows that the stiffness and damping of insulator have an important influence on the braking system noise, which can be reduced by improving the material parameters of the structure layer of the insulator. The test results show that the insulator with one layer of rubber and one layer of steel has a good effect on restraining the low-frequency noise, while the insulator with two layers of rubber and one layer of steel has a good inhibition on the high-frequency noise around 7~8 kHz. The final conclusion shows that a rubber-steel-rubber structure insulator made of a 0.5-mm-thickness steel sheet can reduce the overall incidence of the brake system noise from 19.27% to 1.27%. An appropriate selection of material structure parameters of the insulator can minimize the occurrence of brake squeal.