JPH0540109A - Ultrasonic wave transmitter-receiver - Google Patents

Abstract

PURPOSE:To enable formation or a sound field in an arbitrary body to be inspected, which is optimum both for an analysis of the physical properties of the body and for internal flaw detection therefor, by forming a vibrator to be circular and also by changing the frequency of an electric signal to be transmitted from a signal processing means to the vibrator. CONSTITUTION:An ultrasonic pulser 2 transmits a high-frequency pulse signal to a probe 1 and a vibrator 21 of the probe 1 is excited by this signal and transmits an ultrasonic wave to an ultrasonic wave propagation medium 24. A back sound field wherein the first minimal position corresponding to the position of formation of the circular vibrator 21 is located is formed at the back of an acoustic lens 25, and the first minimal position is shifted by changing the frequency of the high-frequency pulse signal by a frequency converter 3. With the back sound field made to be an optimum sound field in accordance with a purpose of use, an ultrasonic wave is applied from the probe 1 to a body 12 to be inspected, a reflected wave thereof is received and converted into an electric signal by the vibrator 21, and a peak value of the wave is detected by a peak detector 5 and inputted to a microcomputer 7 to be processed. Data obtained by the processing are stored, printed by a printer 8 and displayed on CRT.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic transmitting / receiving apparatus, and more particularly to an ultrasonic transmitting / receiving apparatus suitable for ultrasonic flaw detection and physical property analysis.

[0002]

2. Description of the Related Art In a probe used in a conventional ultrasonic transmitter / receiver, a disk-shaped transducer for performing mutual conversion between an electric signal and an acoustic signal has a concave shape formed on an end face of an ultrasonic wave propagation medium. The probe is formed by being sputtered or adhered on a flat surface facing the acoustic lens, and in such a probe, a so-called point-focusing type probe in which the acoustic wave emitted from the transducer is focused at one point by the acoustic lens. Tentacles are widely used.

When a high-frequency pulse signal is intermittently applied to such a point-focusing type probe from a signal processing circuit, a back surface sound field as shown in FIG. 8 is formed on the back surface of the concave surface of the acoustic lens. That is, the amplitude of the ultrasonic wave has the largest amplitude at the central axis position of the disc-shaped oscillator, and the amplitude gradually decreases as it moves away from the central axis in the radial direction of the ultrasonic propagation medium,
At a certain point, the first minimum value is taken, and then the maximum value and the minimum value are taken, and the values converge to a constant value in a damped manner.

In order to analyze the physical properties of the object using such a probe, a V (z) curve representing the magnitude V of the reflected wave as a function of the distance z between the object and the probe is obtained. And Fig. 9
When the lead or platinum is used as the test object as shown in (4), the reference curve does not have a smooth shape, and peaks and valleys of amplitude occur, resulting in a vibration curve shape. Since it is difficult to accurately analyze the physical properties from the vibration curve V (z) curve, the conventional probe has an ultrasonic wave propagation medium at the first minimum position when the probe is distant from the central axis in FIG. 8 in the radial direction. It was designed so that it would be located on the side surface (the sound field as shown in FIG. 7 (2)).

[0005]

However, when the probe designed as described above is used for ultrasonic flaw detection,
According to the distribution of the back surface sound field, ultrasonic waves with a large incident angle to the subject generate unnecessary waves such as surface waves, worsen the S / N ratio of the reflected wave from the subject, and cannot perform good flaw detection. It had drawbacks.

Further, since the axial length of the ultrasonic wave propagation medium of the probe cannot be changed with the same probe, when the subject changes,
The sound field of the ultrasonic waves incident on the subject is not always the optimum sound field, and depending on the subject, the above-mentioned unnecessary wave is generated and the S / N ratio of the reflected wave is deteriorated. There was also.

The present invention has been made in order to eliminate such drawbacks of the conventional ultrasonic transmitting / receiving apparatus, and forms an optimum sound field for physical analysis of any object and internal flaw detection. It is an object of the present invention to provide an ultrasonic transmitting / receiving device that can be used.

[0008]

SUMMARY OF THE INVENTION An ultrasonic wave transmitting / receiving apparatus of the present invention is a probe provided with a transducer for performing mutual conversion between an electric signal and an acoustic signal facing an acoustic lens, and an electric wave for the probe. In an ultrasonic transmitter / receiver including a signal processing means for transmitting and receiving a signal to perform signal processing, the vibrator is formed in an annular shape, and a frequency of an electric signal transmitted from the signal processing means to the vibrator is changed. It is characterized in that the frequency changing means for controlling is provided in the signal processing means.

A disk-shaped vibrator is provided at the center of the acoustic lens facing surface of the probe, and at least one ring-shaped vibrator is provided outside the disk-shaped vibrator. It is characterized by

Further, a probe in which both sides of a transducer for performing mutual conversion between an electric signal and an acoustic signal are sandwiched by electrodes, and the transducer sandwiched by the electrodes is provided so as to face an acoustic lens, and the probe. In an ultrasonic transmitting and receiving device comprising a signal processing means for transmitting and receiving an electric signal to perform signal processing, at least an electrode provided on the upper surface of the vibrator is formed in an annular shape,
The signal processing means is provided with frequency changing means for changing the frequency of the electric signal transmitted from the signal processing means to the vibrator.

Further, the present invention is characterized in that a disk-shaped electrode is formed in the center of the upper surface of the vibrator, and at least one ring-shaped electrode is formed outside the disk-shaped electrode.

[0012]

In the ultrasonic transmitting / receiving apparatus of the present invention, since the vibrator is formed in an annular shape, the backside sound field of the acoustic lens of the probe is searched for at the first minimum position as shown in FIG. 3 (2). It can be formed so as to be inside the side surface position of the ultrasonic wave propagation medium of the tentacle. Further, since the frequency of the electric signal transmitted to the vibrator can be changed, the minimum position can be freely set according to the subject.

Further, by providing the disk-shaped vibrator and the ring-shaped vibrator, the degree of freedom in forming the back surface sound field according to the subject and the purpose of use is increased.

Further, by forming the electrode provided on the upper surface of the vibrator in a ring shape and changing the frequency of the electric signal applied to the electrode, the above-described operation for forming the backside sound field can be obtained. As a vibrator, a normal disk-shaped vibrator can be used, and it is possible to avoid the point that the strength tends to be weakened with a ring-shaped vibrator, and to replace the conventional ultrasonic transceiver and vibrator. It can be shared and production costs can be kept low.

Further, by forming the disk-shaped electrode and the ring-shaped electrode on the vibrator, not only the strength and production cost of the vibrator but also the flexibility of forming the back sound field can be increased. can get.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the ultrasonic transmitting / receiving apparatus of the present invention.

In FIG. 1, the probe 1 has the structure shown in FIG. That is, as shown in FIG. 2, a vibrator 21 that performs mutual conversion between an electric signal and an acoustic signal is formed in an annular shape, and an upper surface and a lower surface of the vibrator 21 are sandwiched by an electrode 22 and an electrode 23, respectively. .. Electrode 22 is oscillator 21
The electrode 23 has a disk shape and is attached to the upper surface of the ultrasonic propagation medium 24. A concave acoustic lens 25 is formed on the lower end surface of the ultrasonic wave propagation medium 24 facing the transducer 21 side.

The vibrator 21 uses lead zirconate titanate (PZT), which is a kind of piezoelectric ceramic, but zinc oxide (ZnO) or polyvinylidene fluoride (PV) is used.
A material such as DF) may be used. In addition, the electrodes 22 and 23
Uses chromium, but gold may be used.

The electrodes 22 and 23 of the probe 1 are connected to the output terminal of the ultrasonic pulser 2 for generating a high frequency pulse signal, and at the same time, the subject 1 output from the transducer 22.
The input terminal of the ultrasonic receiver 4 that receives and amplifies the electric signal corresponding to the reflected wave from 2 is connected.

The ultrasonic pulser 2 intermittently generates a high frequency pulse signal, and a frequency converter 3 for controlling the frequency of this high frequency pulse signal is connected to the control terminal of the ultrasonic pulser 2.

The output terminal of the ultrasonic receiver 4 is connected to the input terminal of a peak detector 5 for detecting the peak value of the signal input from the ultrasonic receiver 4, and the peak detector 5 is connected.
It is connected to an input terminal of an A / D converter 6 which converts an analog signal input from the device into a digital signal.

The output terminal of the A / D converter 6 is connected to the input port of the microcomputer 7. The output port of the microcomputer 7 holds the input terminal of the printer 8 that prints the data processed by the microcomputer 7, the input terminal of the CRT 9 that displays the data, and the subject 12 in the X, Y, and Z directions. The input terminal of the controller 10 that controls the scanner 11 to be moved is connected. The output terminal of the controller 10 is connected to the input terminal of the scanner 11.

Of the above-mentioned constituent circuits, the ultrasonic pulser 2,
Frequency converter 3, ultrasonic receiver 4, peak detector 5,
The A / D converter 6 and the microcomputer 7 constitute signal processing means for transmitting / receiving an electric signal to / from the probe 1 to perform signal processing.

Next, the operation of this embodiment will be described.

The ultrasonic pulser 2 transmits a high-frequency pulse signal that is intermittently output to the probe 1, and the transducer 21 of the probe 1 is excited by the high-frequency pulse signal and propagates ultrasonic waves by ultrasonic waves. Send into medium 24. As a result of this ultrasonic wave, the back surface of the acoustic lens 25 of the ultrasonic wave propagating medium 24 appears on the back side of
As shown in (2), the backside sound field having the first minimum position is formed within the backside position of the acoustic lens 25 corresponding to the formation position of the annular transducer 21. The initial minimum position of the back surface sound field can be moved as shown in FIG. 4 by changing the frequency of the high frequency pulse signal by the frequency converter. That is, when the frequency of the high-frequency pulse signal is increased, the first minimum position moves in the central axis direction of the ultrasonic wave propagation medium 24, and when the frequency is decreased, it moves in the lateral position direction.

In this way, the ultrasonic wave from the probe 1 to the object 12 (acoustic lens of the probe 1) is used as the optimum sound field of the back surface sound field according to the purpose of use such as ultrasonic flaw detection and physical property analysis. Two
5, a point-focusing ultrasonic wave that focuses on one point is emitted, and the reflected wave from the subject 12 is received by the probe 1.

The reflected wave received by the probe 1 and converted into an electric signal by the transducer 21 is amplified by the ultrasonic receiver 4,
The peak value is detected by the peak detector 5. This peak value is converted into a digital signal by the A / D converter 6 and input to the microcomputer 7. The microcomputer 7 performs various kinds of data processing such as calculation of a V (z) curve as shown in FIG. 9 from the input reflected wave data, stores the processed data, and prints it by the printer 8. Further, it is displayed on the CRT 9.

The microcomputer 7 also outputs a control signal to the controller 10, and the controller 10 controls the scanner 11 based on the control signal to move the sample 12 to a required position.

FIG. 5 is a top view and a sectional view showing another embodiment of the ultrasonic probe 1 used in the ultrasonic transmitting / receiving apparatus of the present invention. 5, the same components as those in the embodiment of FIG. 2 are designated by the same reference numerals, and the description thereof will be omitted.

In the present embodiment, the ultrasonic wave propagation medium 24
A disk-shaped vibrator 27 and a disk-shaped electrode 26 attached to the upper surface of the vibrator 27 are provided inside the annular vibrator 21 and the electrode 22 on a plane facing the acoustic lens 25 on the central axis of the. It is provided in. The electric signal from the ultrasonic pulser 2 is independently supplied to each of the annular electrode 22 and the disc electrode 26. However, the lower electrode 23 is used as a common electrode.

In this embodiment, when a high-frequency pulse signal is applied from the ultrasonic pulser 2 only to the annular electrode 22, the acoustic lens 25 corresponding to the formation position of the annular transducer 21 as shown in FIG. 6 (2). The backside sound field having the first minimum position is formed within the backside position of, and a sound field suitable for ultrasonic flaw detection can be formed. Of course, it is also possible to change the frequency of the high frequency pulse signal transmitted from the ultrasonic pulser 2 by the frequency converter 3 to change the distribution shape of the back surface sound field.

When the high-frequency pulse signal is applied only to the disk-shaped electrode 26, it is placed outside the back surface position of the acoustic lens 25 corresponding to the formation position of the annular vibrator 21, as shown in FIG. 7B. A back sound field with the first minimal position is formed,
A sound field suitable for physical property analysis of the subject 12 can be formed.

In the above embodiment, the transducer 2 of the probe 1 is used.
1, 27 and the upper electrodes 22 and 26 are formed in a circular ring shape and a disk shape, respectively, but the vibrator is formed in a large disk shape, and only the upper electrode is formed in a circular shape and a small disk shape. Can obtain almost the same back sound field. By doing so, it is possible to avoid the mechanical weakness that tends to occur in the ring-shaped vibrator, and the mass-production effect can be obtained by sharing the disk-shaped vibrator with other models. You can also get the advantage.

The electrodes 22, 23, 26 and the vibrator 2
The method of attaching 1 and 17 to each other and to the ultrasonic wave propagation medium 24 is not limited to the sticking method, and may be another method such as a sputtering method.

[0036]

Since the ultrasonic transmitter / receiver of the present invention is configured as described above, a single probe can be used to optimize the sound field for physical analysis and internal flaw detection of an arbitrary object. Can be formed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an exemplary embodiment of the present invention.

2A and 2B are a top view and a cross-sectional view of an embodiment of the probe used in the embodiment of FIG.

3A and 3B are a top view of the probe shown in FIG. 2 and a diagram showing an example of a backside sound field corresponding to a transducer position of the probe.

FIG. 4 is a diagram showing various examples of a back surface sound field of the probe shown in FIG.

5A and 5B are a top view and a cross-sectional view of another embodiment of the probe used in the embodiment of FIG.

6A and 6B are a top view of the probe shown in FIG. 5 and a diagram showing an example of a back surface sound field corresponding to a transducer position of the probe. (When the vibrator 22 vibrates)

7A and 7B are a top view of the probe shown in FIG. 5 and a diagram showing another example of the backside sound field corresponding to the transducer position of the probe. (When the vibrator 26 vibrates)

FIG. 8 is a diagram showing amplitude characteristics as an example of a back surface sound field.

FIG. 9 is a diagram showing an example of a V (z) curve.

[Explanation of symbols]

 1 Probe 2 Ultrasonic Pulser 3 Frequency Converter 4 Ultrasonic Receiver 5 Peak Detector 7 Microcomputer 10 Controller 11 Scanner 12 Subject

Claims (4)

[Claims] 1. A probe provided with a transducer for performing mutual conversion between an electric signal and an acoustic signal facing an acoustic lens, and a signal processing means for transmitting and receiving the electric signal to and from the probe to perform signal processing. In the ultrasonic transmission / reception apparatus having the above-mentioned, the transducer is formed in an annular shape, and the signal processing means is provided with frequency changing means for changing the frequency of an electric signal transmitted from the signal processing means to the transducer. An ultrasonic transmitter / receiver characterized by the following. 2. A disk-shaped vibrator is provided at the center of the acoustic lens facing surface of the probe, and at least one ring-shaped vibrator is provided outside the disk-shaped vibrator. The ultrasonic transmission / reception device according to claim 1. 3. A probe in which both sides of a transducer for performing mutual conversion between an electric signal and an acoustic signal are sandwiched by electrodes, and the transducer sandwiched by the electrodes is provided so as to face an acoustic lens, and the probe. In an ultrasonic transmitter / receiver including a signal processing means for transmitting and receiving an electric signal to perform signal processing, at least an electrode provided on an upper surface of the vibrator is formed in an annular shape, and the vibrator is provided from the signal processing means. An ultrasonic transmitting / receiving apparatus, characterized in that the signal processing means is provided with frequency changing means for changing the frequency of an electric signal transmitted to the user. 4. The super according to claim 3, wherein a disk-shaped electrode is formed in the center of the upper surface of the vibrator, and at least one ring-shaped electrode is formed outside the disk-shaped electrode. Sound wave transmitter and receiver.