JPH084358B2 - Ultrasonic transducer - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic transducer for measuring distance and detecting the presence or absence of an object using ultrasonic waves.

2. Description of the Related Art In recent years, there is an increasing tendency to use ultrasonic waves to measure distance and detect the presence or absence of an object. Conventionally, in the case of a low-frequency transducer with a long measurement distance but poor accuracy, a net is put on the front surface of the ultrasonic transducer to protect the ultrasonic transducer surface. On the other hand, a high-frequency oscillator with a short measurement distance but high accuracy is used without protection because it has a large amount of energy attenuation with respect to air.

A conventional ultrasonic transducer will be described below with reference to the drawings. FIG. 3a is a sectional view of a conventional low frequency oscillator, and FIG. 3b is a plan view of a conventional low frequency oscillator.
Reference numeral 1 is a shield wire for transmitting and receiving electric signals. Reference numeral 2 denotes an outer case made of aluminum, which covers the ceramic vibrator and maintains the parallelism of the sensor. Reference numeral 3 denotes a concave-circular vibrator made of ceramic, which has a role of converting an electric signal into an ultrasonic wave and converting the ultrasonic wave into an electric signal. Reference numeral 4 is a protective case made of aluminum which protects the ceramic vibrator whose surface is easily damaged and maintains the parallelism of the sensor. 5 is a net stretched on the front surface to protect the ceramic vibrator whose surface is easily damaged.

FIG. 4 is a sectional view of a conventional high frequency oscillator. Reference numeral 1 is a shield wire for transmitting and receiving electric signals. Reference numeral 2 denotes an outer case made of aluminum, which covers the ceramic vibrator and maintains the parallelism of the sensor. 3 is a concave circular ceramic oscillator made of ceramic, which converts electrical signals into ultrasonic waves,
It is a ceramic oscillator that has the role of converting ultrasonic waves into electrical signals. Reference numeral 6 is an ultrasonic wave emitted from the ceramic vibrator 3. 7 is an object to be measured. Reference numeral 8 indicates a portion where the ultrasonic waves are narrowed down by the directivity of the ultrasonic waves emitted from the ceramic vibrator 3.
That is the focus. 9 is a position where the ultrasonic wave hits the DUT 7.

The operation of the ultrasonic transducer configured as described above will be described below.

A voltage is applied to the ceramic oscillator 3 to generate an ultrasonic wave 6 and the ultrasonic wave 6 is emitted to the DUT 7. Then, the ultrasonic wave 6 reflected from the DUT 7 is received by the ceramic vibrator 3, and the ultrasonic wave 6 is converted into a voltage.

Problems to be Solved by the Invention However, in the configuration as described above, in the ultrasonic transducer of FIG. 3, although the ultrasonic transducer surface is protected, the direction of the ultrasonic wave 6, the focal point 8 and the ultrasonic wave 6 has a drawback that the position 9 corresponding to the DUT 7 is difficult to see. Also,
Since the ultrasonic transducer in Fig. 4 is used without protection,
The ultrasonic transducer surface is not protected, and there is a drawback that the direction of the ultrasonic wave 6, the focal point 8 and the position 9 where the ultrasonic wave 6 hits the DUT 7 are difficult to understand. That is, since the diameter of the focal point 8 of the ultrasonic wave 6 is quite small, it was difficult to understand the position 9 where the ultrasonic wave 6 hits the DUT 7.

Therefore, in view of the above drawbacks, the present invention provides an ultrasonic transducer in which the surface of the ultrasonic transducer is protected and the direction of the ultrasonic wave, the focus, and the position where the ultrasonic wave hits the object to be measured can be easily obtained.

Means for Solving the Problems The ultrasonic vibrator of the present invention has an opening in the ultrasonic vibrator,
A cap having a conical shape with a through hole at the tip is provided.

Action With this configuration, the protective portion is a conical shape having a through hole, which indicates the direction of the ultrasonic wave generated from the ultrasonic transducer, the focal point, and the position where the ultrasonic wave hits the DUT. It serves to understand the positional relationship between the object to be measured and the ultrasonic transducer and protect the ultrasonic transducer surface.

Example Hereinafter, as an example of the present invention, the case of using it in an ultrasonic sensing system will be described with reference to the drawings.

1 and 2 are cross-sectional views of an ultrasonic transducer according to an embodiment of the present invention. Reference numeral 11 is a shield wire for transmitting and receiving electric signals. 12 is an outer case made of aluminum that covers the ceramic vibrator and maintains the parallelism of the sensor. 13
Is a ceramic vibrator having a concave circular shape and made of ceramic, which converts an electric signal into an ultrasonic wave and an ultrasonic wave into an electric signal. Reference numeral 14 is a cap made of resin or the like having a conical shape with a through hole cut out.

The operation of the ultrasonic transducer configured as described above will be described below.

First, a voltage is applied to the ceramic vibrator 13 and ultrasonic waves 15
Is generated and emitted to the DUT 16. At that time, cut off the tip as shown in the figure
Direction, the focal point 17, and the position where the ultrasonic wave 15 hits the DUT 16, and the surface of the ultrasonic transducer is protected. Further, the ultrasonic wave 15 reflected from the object to be measured is received by the ceramic vibrator 13 and converted into a voltage.

As described above, according to the present embodiment, at the time of setting and testing, the direction of the ultrasonic wave, the focus, and the position where the ultrasonic wave hits the object to be measured can be easily known, and the ultrasonic transducer surface can be protected. it can. Further, in the case of low frequency, it is needless to say that the protective part may be removable because the convergent diameter of ultrasonic waves is large.

EFFECTS OF THE INVENTION As described above, the present invention is made of a resin such as a cone-shaped resin with a cut-through tip that indicates the direction of an ultrasonic wave generated from an ultrasonic transducer, the focal point, and the position where the ultrasonic wave hits the DUT. By providing a protective cap, the direction of ultrasonic waves,
The focal point and the position where the ultrasonic wave hits the object to be measured can be easily known, and the surface of the ultrasonic transducer can be protected, and its practical effect is great.

[Brief description of drawings]

1 and 2 are cross-sectional views of an ultrasonic transducer according to an embodiment of the present invention, and FIGS. 3a and 3b are cross-sectional views and plan views of a conventional low-frequency ultrasonic transducer, and FIG. It is sectional drawing of the conventional ultrasonic transducer for high frequencies. 10 …… Cap, 11 …… Shield wire, 12 …… Outer case,
13 ... Ceramic oscillator.

Claims (2)

[Claims] 1. An ultrasonic vibrator comprising a ceramic vibrator, wherein an ultrasonic vibrator is provided with a conical cap having a through hole at a tip thereof at an opening of the ultrasonic vibrator. 2. The ultrasonic transducer according to claim 1, wherein the cap is removable.