Ball joints, one type of joint applied as an automobile exhaust system joint, will often generate an abnormal noise upon oscillation. The noise generating mechanism of this phenomenon is explained using element analysis and friction characteristic analysis of the materials making up the surfaces of the joints. It was found that the roundness of the flare flange of ball joints which generate noise is imprecise. This causes the flange to come in partial contact with the spherical gasket eventually resulting in abnormal wear of the guard net in the gasket. The particles resulting from this wear accumulate on the gasket surface, where the stick-slip phenomenon then causes the noise. A study was also conducted to determine input frequency for oscillation angle and temperature of the ball joint during the use of an actual vehicle. The fabrication of a simple excitation device that could apply those input conditions made it possible to conduct a bench evaluation of the noise. This bench test method was used to conduct parameter studies of design variables that significantly affect the generation of the noise. The bench test was also used to determine the range of settings for set spring load and the flare roundness wherein the noise will not be generated.
Article of Honda R&D Technical Review Vol.13 No.2 (149 - 158)