Patent attributes
In a vibration welding structure for fixing an attachment to an instrument panel (12), a first projection (70) resiliently deformable in a predetermined vibrating direction is provided on the instruction panel (12) so as to project from the instrument panel (12) toward an air conditioner duct (15). A first fitting groove portion (72) is formed in the air conditioner duct (15) for fitting engagement with a distal end portion (70a) of the first projection (70). Further, a first positioning mechanism (74) is provided between the instrument panel (12) and the air conditioner duct (15) for positioning the air conditioner duct 15 in a direction perpendicular to the vibrating direction.