| 摘要 |
PROBLEM TO BE SOLVED: To enable the engagement of sound insulation walls forming an air layer therebetween to be hardly disengaged as well as creating an air layer (closed space) by thrusting the sound insulation walls into a large diameter cylindrical part by rather a weak force. SOLUTION: The grommet comprises a large diameter cylindrical part 31 fixed in a panel through hole Pa, a small diameter cylindrical part 33 through which an electric wire W is passed, a conical shielding wall 34 connecting the small diameter cylindrical part with the large diameter cylindrical part, and a conical shielding wall 35 with the inner peripheral end of which being joined with the outer periphery of the small diameter cylindrical part and expanded outward. The shielding wall 35 creates a closed space 37 with shielding wall 34 inbetween in making the wall 35 to be displaced to the front end side of the small diameter cylindrical part 33 and the outer peripheral end of which is to be climed over the engaging protruded part 39 on the inner periphery of the large diameter cylindrical part and when the displacement is relieved from this condition, the outer peripheral end is engaged with the engaging protruded part of the large diameter cylindrical part causing the inversion of the shielding wall 35 so as to make it into a reversed conical walled shape of the intial shape with the inner peripheral side part as a fulcrum, thereby forming a closed space with the shielding wall 34 inbetween. The sound insulation wall is constituted to be flexible and the annular engaging protruded part 39 is provided with several slits 40 in the peripheral direction to make it flexible too. |
