하이드로 부시가 차량 제동성능에 미치는 영향

Anti-vibration rubbers are applied to vehicle suspension systems. Generally, conventional type rubber has good isolation performance at high frequency range due to low dynamic stiffness. But, it isn’t suitable for use at resonance occurrence because of low damping coefficient. Therefore, many hydraulic bushes are used in vehicle to reduce vibration and noise caused by structure resonance. Hydraulic bush consists of main rubber part and fluid part. Main rubber part plays an elastic role (stiffness), and fluid part plays a viscose role (damping).Hydraulic bushes are classified by inertia track type. Kinematic type has inertia track with long length and wide area, and has low volume stiffness. Friction type has inertia track with short length and narrow area, and has high volume stiffness. Hybrid type has middle property between kinematic type and friction type. In this paper, we experiment vehicle brake judder test by using these hydraulic bush types. To make brake judder, we make specially brake disc by machining. We are measured displacements and accelerations at radial and axial directions of hydraulic bushes under braking 0.7G, 0.5G, and 0.2G conditions. Finally, we can find hydraulic parameters with high sensitivity of brake judder performance.