Ultrasonic wave sensor and method for attaching ultrasonic wave sensor

摘要

An ultrasonic sensor of the present invention is attached to the back face of a bumper 4, and provided with a matching member 3 that is in intimate contact with the ultrasonic wave transmitting surface of the ultrasonic sensor and the opposing face of the bumper 4 and that has an acoustic impedance smaller than each of the impedances of the sensor and the bumper.

主权项

1. An ultrasonic sensor attached to the back face of a bumper, comprising: a matching member that is in intimate contact with the opposing faces between an ultrasonic wave transmitting surface of the ultrasonic sensor and the bumper, and that has an acoustic impedance smaller than each of the impedances of the sensor and the bumper,
wherein the matching member is composed of a member having a first acoustic impedance and a member having a second acoustic impedance, an aspect ratio is provided in the shape of the contact surface between at least one of the members and the bumper, and the acoustic impedances of the members is given by the following relation:
Z21>>Z22 where Z21 is the acoustic impedance of a first member in the central portion thereof, and Z22 is the acoustic impedance of a second member in the peripheral portion thereof.