| 摘要 |
PROBLEM TO BE SOLVED: To obtain a ultrasonic wave sensor where the directivity, that is, a radiation spread angle can be made narrow in spite of a simple configuration. SOLUTION: The ultrasonic wave sensor is provided with a cylinder section (support cylinder section) 22 of a cylindrical case 2 whose bottom 21 is formed in a diaphragm and on which an ultrasonic wave vibrator 1 is fixed and with an interposition member 4 that is placed between an outer frame 3 and the case 2 to absorb vibration energy. The interposition member 4 has a groove 42 that is close to a circumferential edge of the diaphragm 21 and not closely adhered to the support cylinder 2 of the cylindrical case 2. The groove 42 of this interposition member 4 may be provided over the entire circumference or provided over a prescribed angular range in the circumferential direction. In the case of providing the groove 42 of the interposition member 4 over the entire circumference of the diaphragm 21, the directivity of an ultrasonic wave energy emitted from the sensor, that is, a radiation spread angle can be made narrow, and in the case of providing the groove 42 of the interposition member 4 over a prescribed angular range in the circumferential direction of the diaphragm 21, the directivity of the ultrasonic wave energy emitted from the sensor, that is, the radiation spread angle can be made narrow at a side at which the groove 42 is provided.
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