Patent ID: 7545082

Claim:
An ultrasonic sensor device comprising: an ultrasonic transducer that includes: a tubular housing having a bottom; a piezoelectric element that is fixed to an inner surface of the bottom of the tubular housing; and a vibrating surface that is an outer surface of the bottom of the tubular housing; a hollow case that includes an opening surface, through which the hollow case receives the ultrasonic transducer such that the vibrating surface is externally exposed; a limiting means for limiting an impact due to a collision by an object from being transmitted to the vibrating surface, wherein the limiting means is located over the vibrating surface; and a tubular vibration-limiting member that is located at a periphery of the ultrasonic transducer, wherein: the ultrasonic transducer is provided inside the hollow case through the tubular vibration-limiting member; and the tubular vibration-limiting member limits a vibration from traveling between the ultrasonic transducer and the hollow case.