クラッチプレートの摩擦振動に着目した湿式クラッチの騒音発生メカニズムに関する研究

Abstract

Gears of automatic transmissions are shifted with friction force of a multiplate wet clutch. In the wet friction clutch, undesirable vibration and noise can occur when gears are shifted. In this study, we conducted experiments on vibration and noise to understand the generation mechanism in a wet clutch system. An experimental setup was designed to realize a system composed of a transmitting shaft and a clutch drum to fix a separator plate (S/P) in a wet friction clutch. A friction plate (F/P) was rotated by a motor and the S/P was pressed down on F/P. The shaft was supported by a leaf spring which gave the torsional stiffness. The vibration of the transmitting shaft and the S/P were measured with a laser displacement sensor and a 3-axis accelerometer, respectively. Another 3-axis accelerometer was attached to the top of the clutch drum to measure the bending vibration of the shaft-clutch drum system. The sound pressure was measured with a microphone. The results to be obtained are as follows: (1) The S/P's out-of-plane and radial acceleration waveform of around 120 Hz and the sudden increase of sound pressure of around 940 Hz were observed just after the contact state between the S/P and the F/P transited from stick to slip. (2) The S/P's circumferential acceleration waveform of around 470 Hz was observed at the same timing. (3) The clutch drum's circumferential and radial acceleration waveform of around 500 Hz and its out-of-plane acceleration waveform of around 260 Hz were observed just after the contact state between the S/P and the F/P transited from stick to slip. (4) The clutch drum's circumferential and radial acceleration waveform of around 1460 Hz was observed just after the relative velocity between the S/P and the F/P marked its local maximum value.