GROMMET

摘要

PROBLEM TO BE SOLVED: To create an air layer (closed space) by preventing engagement of a second insulation wall for forming the air layer from being disengaged easily, and preventing the sound insulation wall from entering a large-diameter cylindrical section with a small force. SOLUTION: The grommet comprises the large-diameter cylindrical section 21, fixed to a panel through hole Pa, a small-diameter cylindrical section 33 where an electric wire W is passed through, an insulation wall 34 in a conical wall shape for connecting the large-and small-diameter cylindrical sections, and the sound insulation wall 35 in a conical wall shape where an inner-periphery end 35b is jointed to the outer periphery of the small-diameter cylindrical section for expanding toward the outside. In the sound insulation wall 35, an outer-periphery end 35a slides along an inner periphery 31a of the large-diameter cylindrical section when the small-diameter cylindrical section 33 is displaced to the side of a tip 33a. When the displacement is cancelled from that state, the outer-periphery end is engaged to a hooking section 39 of the large-diameter cylindrical section for inverting in a conical wall shape in an opposite direction to an initial shape with the inner-periphery end 35b of itself as a support, thus forming the closed space 37 at an area to the sound insulation wall 34. The outer-periphery end of the sound insulation wall has a cylindrical section 45, that is subjected to friction engagement to the inner periphery of the large-diameter cylindrical section, and a thin, cylindrical displacement absorption section 46 is provided at the base section of the cylindrical section.