Patent attributes
An ultrasonic sensor includes an ultrasonic microphone having a circular vibration surface, a substantially cylindrical cushion unit where the ultrasonic microphone is inserted, and a case unit which has a fitting portion provided with a cylindrical engagement hole therein. The cushion unit and the fitting portion are respectively provided with cushion-side guide portions and fitting-side guide portions which are to be engaged with each other, so that the cushion unit is axially guided to be inserted into the fitting portion and restricted from circumferentially rotating. The cushion unit has cushion-side engagement portions, which are engaged with case-side engagement portions of the fitting portion and capable of bending toward a diametrically inner side of the cushion unit in the insertion of the cushion unit into the fitting portion.
