JP2006333086A - Ultrasonic sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that since a conventional ultrasonic sensor flatly measures with an ultrasonic wave radiation surface, an air bubble and dirt easily stick on the ultrasonic wave radiation surface and then the ultrasonic sensor decreases in sensitivity and is then disabled to take measurements. <P>SOLUTION: A case 1, piezoelectric ceramics 2, a cable 4, a cord 5 led out of the cable 4, and a connector 6 have the same constitution with a conventional example, so explanations are omitted. In this embodiment, a conic ultrasonic wave radiation surface is formed which has its center 1c projected on an opposite surface of a case 1 where the piezoelectric ceramics 2 are mounted and is provided with a slope 1d around the center 1c. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an ultrasonic sensor in which a central portion protrudes and an inclined surface is provided around the center portion.

Conventionally, in an ultrasonic sensor that continuously measures the interface position in a tank with water level fluctuation,
As shown in FIG. 3, a piezoelectric ceramic 2 is attached to the bottom of the case 1, a resin 3 is filled around the piezoelectric ceramic 2, and a cable 5 for pulling out a cord 4 connected to the piezoelectric ceramic 2 is provided in the case 1. An ultrasonic sensor fixed by a connector 6 attached to the drawer 1a has been proposed.

However, in the conventional ultrasonic sensor configured as described above, since the ultrasonic radiation surface 1b on the outer surface of the case 1 to which the piezoelectric ceramic 2 is attached is formed flat, bubbles and dirt are present on the ultrasonic radiation surface 1b. When it is easy to attach, the sensitivity decreases, and the degree of adhesion of bubbles and dirt increases, there is a problem that measurement is impossible.
JP-A-10-122936

    The problem to be solved is that in the conventional ultrasonic sensor, since the ultrasonic radiation surface is formed flat, bubbles and dirt are easily attached to the ultrasonic radiation surface, the sensitivity is lowered, and measurement becomes impossible. There is a problem.

  In the present invention, the piezoelectric ceramic is attached to the bottom of the case, the cable is connected to the piezoelectric ceramic and the cable is pulled out of the case, and the center protrudes from the outer surface of the case facing the piezoelectric ceramic. A conical ultrasonic radiation surface provided with an inclined surface is formed.

  In the ultrasonic sensor according to the present invention, since the conical ultrasonic radiation surface is formed on the outer surface of the case facing the piezoelectric ceramic, the bubbles and dirt move along the conical inclined surface, and the bubbles are formed on the ultrasonic radiation surface. Since it is difficult to get dirt and dirt, there is an advantage that the sensitivity does not decrease and the directivity does not deteriorate.

  In the present invention, the disadvantages that the directivity characteristics are deteriorated and the sensitivity is deteriorated is eliminated by forming a conical ultrasonic radiation surface having a center protruding from the ultrasonic radiation surface of the case and provided with an inclined surface.

  1 is a side view of an ultrasonic sensor according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the ultrasonic sensor of FIG. 1, 1 is a case, 2 is piezoelectric ceramics, 4 is a cable, 5 is drawn from the cable 4 6 is a connector, and since these structures are the same as those of the above-described conventional example, description thereof is omitted. In this embodiment, a center 1c is formed on the opposing outer surface of the case 1 to which the piezoelectric ceramic 2 is mounted. A conical ultrasonic radiation surface that protrudes and is provided with an inclined surface 1d around the center 1c is formed.

  In the ultrasonic sensor of the present embodiment configured as described above, the center 1c protrudes from the ultrasonic radiation surface of the case 1 and the inclined surface 1d is formed around the center 1c. It floats upward on the inclined surface 1d of the surface, and bubbles and dirt can be prevented from adhering to the ultrasonic radiation surface.

  In the above embodiment, the ultrasonic radiation surface of the case 1 has a conical shape that protrudes from the center and has an inclined surface around it. However, the ultrasonic radiation has a curved surface at the center and an inclined surface around it. The same effect can be obtained also in terms of surface.

It is a side view of the ultrasonic sensor of the Example of this invention. It is sectional drawing of the ultrasonic sensor of the Example of FIG. It is side surface sectional drawing of the conventional ultrasonic sensor.

Explanation of symbols

1 Case 2 Piezoelectric Ceramics 4 Cable 5 Cord 6 Connector

Claims (2)

  A piezoelectric ceramic attached to the bottom of the case and a cable for drawing a cord connected to the piezoelectric ceramic from the drawer of the case, the center of the case protruding from the outer surface facing the piezoelectric ceramic, the center An ultrasonic sensor characterized by forming a conical ultrasonic radiation surface provided with an inclined surface around.   2. The ultrasonic sensor according to claim 1, wherein the ultrasonic radiation surface is provided with a curved surface at a central portion and an inclined surface is formed around the central surface.

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