JPH0227666Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to the structure of a drain hole in an ultrasonic sensor of an ultrasonic detector.

[Background technology]

As shown in FIG. 1, the conventional ultrasonic sensor includes a case 1, a drip-proof ultrasonic transducer 2 housed in the case 1, and the transducer 2 held in the case 1. In order to prevent water entering through the opening of the horn 4 from staying in the space in front of the vibrator in the case 1, a drain hole formed in the case 1a and the case 1b is provided. was.

In the sensor with the above configuration, the ultrasonic waves 6 emitted from the vibrator 2 and exited from the drain hole 5 are transmitted to the case 1.
There have been problems in that receiving reflected waves 8 reflected by the outer reflective surface 7 may cause malfunctions or aggravate reverberant vibrations that remain after the vibrator 2 is driven.

[Purpose of invention]

The present invention has been made to improve the above points, and its purpose is to provide an ultrasonic sensor with a drain hole that has a structure that reduces the leakage of ultrasonic waves to the outside. be.

[Disclosure of invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below based on drawings showing examples thereof.

FIG. 2 is a sectional view showing essential parts of an embodiment of the present invention. The drain hole 9 of this embodiment has a reflecting plate 1a' that reflects the ultrasonic waves emitted from the vibrator 2 of the sensor into the case 1, as shown in the figure. The above-mentioned reflector 1a' is the case 1 in FIG.
Case 1b is formed by extending in the longitudinal direction, and case 1b is reduced in the longitudinal direction to form 1b'. In this embodiment, most of the ultrasonic wave 10 emitted from the vibrator 2 and entering the drain hole 9 is reflected by the reflection plate 1a' of the case 1, and returns to the vibrator 2 as a reflected wave 11. .
The ultrasonic waves 12 emitted from the outside of the case 1 are minute;
Reflected waves from external reflective surfaces have almost no effect. Water that has entered the inside of the case 1 passes through the drain hole 9 and exits to the outside of the case. If the reflecting plate 1a' is sloped, water can easily escape.

According to experiments, the ultrasonic waves leaking to the outside from the drain hole 9 of this embodiment was reduced by 6 [dB] compared to the case of the drain hole 5 of the conventional example.

The reflecting plate according to the present invention is not limited to the above-mentioned configuration, but may have any configuration as long as the ultrasonic waves are reflected inside the sensor.

[Effect of idea]

As described above, according to the present invention, the ultrasonic waves emitted from the ultrasonic vibrator of the sensor are transmitted to the drain hole provided in the case of the ultrasonic sensor of the ultrasonic detector.
Since a reflecting plate was formed inside the case, it was possible to provide an ultrasonic sensor having a drain hole and structured to prevent ultrasonic waves from leaking to the outside.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an ultrasonic sensor related to a conventional ultrasonic detector, and FIG. 2 is a sectional view showing a main part of an embodiment of the present invention. 1, 1b'...Case, 1a'...Reflector, 9...
Drain hole, 10...Ultrasonic wave, 11...Reflector.

Claims (1)

[Scope of utility model registration request] In the ultrasonic sensor having a water drain hole, a reflecting plate is formed in the water drain hole to reflect the ultrasonic waves emitted from the ultrasonic transducer in the ultrasonic sensor into the ultrasonic sensor. Features of ultrasonic sensor.