Katsutoshi Ohta

Dynamic Characteristics of a Mount Consisting of Support Rubbers and a Leaf Spring with a Rigid Mass at One End

A mount consisting of support rubbers and a leaf spring carrying a rigid mass at one end is discussed to realize a high level of damping over a discrete frequency range which is characteristic of hydraulic mounts. The analysis model of this mount based on Bernoulli-Euler theory of beam vibration is developed to characterize the frequency response of damping and stiffness for the mount. The excitation testing and analysis shows that this mount can provide a damping peak in a low frequency range of 10-15 Hz, which is typically required for hydraulic engine mounts to control automotive engine shake for ride comfort. The effects of the leaf spring length, the dynamic stiffness and loss factor of a support rubber, and the rigid mass on the damping characteristic of the mount are examined by using the analysis model. The effectiveness of this mount on the reduction of engine shake is demonstrated through on-vehicle testing. The extremely narrow frequency band of the damping peak compared with that of hydraulic mounts is a future research issue to be addressed.