| 摘要 |
PROBLEM TO BE SOLVED: To obtain high-reliability operation by suppressing an ultrasonic output or input signal change with respect to an environmental temperature change, in simple configuration, in a protection housing for an open type ultrasonic transmitting/receiving unit and an ultrasonic sensor. SOLUTION: An ultrasonic sensor 10 comprises a protection housing 1 and an open type ultrasonic transmitting/receiving unit 2 (ultrasonic unit 2). The protection housing 1 includes a cylindrical body 11 surrounding a case 20 of the ultrasonic unit 2. An open space 3, which is opened forward, is formed from a forwardly extending wall surface 12 of the cylindrical body 11. The protection housing 1 comprises a sound absorbing member 4 in contact with the wall surface 12 and at a node of resonance mode in the open space 3. The sound absorbing member 4 suppresses low sharpness of resonance in the open space 3 of the protection housing 1, thereby suppressing a degree of ultrasonic output change with respect to environmental temperature change and achieving high-reliability operation of the ultrasonic sensor 10. COPYRIGHT: (C)2010,JPO&INPIT
|
