| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a grommet which can increase the number of reflection and damping of noise to create an excellent sound absorbing function. SOLUTION: On the outer surface of the enlarged-diameter part 4 of a grommet 1 on the engine room side, multiple layers of sound absorbing pleats 5a, 5b, 5c are provided to be projected in the axial direction with radial spaces. Further, ribs 6 are provided to be radially swelled out on both sides at intervals on the tips and on the intermediate parts of the respective sound absorbing pleats 5a, 5b, 5c. The respective ribs 6 are radially positioned alternately between the adjacent sound absorbing pleats 5a, 5b, 5c. In this manner, the sound absorbing pleats 5a, 5b, 5c, and the ribs 6 are provided on the outer surface of the enlarged-diameter part 4 on the engine room side X, and thus about zigzag cavities are formed on the outer surface of the enlarged-diameter part 4. Thus, since the areas in which noise collides with each other, are increased and the noise strikes the respective sound absorbing pleats 5a, 5b, 5c, and the ribs 6 to be reflected and damped, the noise can be effectively absorbed.</p> |
