| 摘要 |
PURPOSE:To reduce a sneak path due to direct waves and facilitate the mounting of a ultrasonic range finder to an equipment by incorporating a transmitting and receiving ultrasonic transducer into an integrally structured sensor unit and setting a mounting position for reducing the effect of direct waves. CONSTITUTION:Transmitting and receiving horns 18 and 19 are provided on their throats with mounting portions 20 and 21 and a transmitting ultrasonic transducer 17 and a receiving ultrasonic transducer 24 is fixedly mounted to the mounting portions 20 and 21 via buffers 22 and 23, respectively, for increasing vibration absorptivity. Since the level of the direct waves changes in accordance with a directivity determined by the ultrasonic transducers and the horns and the mechanical vibration interference of sensor units, the pitch spacings between the transmitting and receiving ultrasonic transducers 17 and 24 and between the transmitting and receiving horns 18 and 19 are set to 60mm-120mm as the spaces to minimize the effect of the direct waves, considering an optimum pitch for raising the level of received waves reflected from a target object. Thus, the generation of a malfunction due to a direct sneak path possibly generated by the condition of mounting to an equipment is prevented.
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