JPS58201059A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To arrange oscillators at optional intervals and to prevent the unnecessary oscillation which is generated when high-voltage pulses are impressed, by setting the width of oscillators to an about quarter of the ultrasonic wavelength and inserting a flexible acoustical absorbent between oscillators and taking out the electrode of each oscillator from a face crossing the side face of the oscillator array. CONSTITUTION:N pieces of ultrasonic oscillators 2(1)-2(n) having a minute width are arranged continuously in an array ultrasonic probe 1, and a coating material 3 is brought closely into contact with the acoustic wave transmitting/receiving face, and a packing material 4 for suppressing reverberations at an oscillator excitation time and an acoustic wave reception time is brought closely into contact with the rear face, and a flexible acoustical absorbent 5 having a high acoustic wave absorptivity is inserted between oscillators and is brought closely into contact with them. A common electrode 6a is formed on the side of the acoustic wave transmitting/receiving face of oscillators, and respective electrodes 6b(1)-6b(n) of oscillators are formed on the face side opposite to this face, and the common electrode 6a is taken out directly by a signal line 7a, and signal lines 7b(1)-7b(n) are inserted through the packing material 4 to take out electrodes 6b(1)-6b(n) from upper faces of oscillators, namely, the face crossing the side face of the oscillator array.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to improvements in array-type ultrasonic probes used in electronic scanning ultrasonic flaw detection methods.

[Technical background of the invention and its problems]

Conventionally, array-type ultrasonic probes used in electronic scanning ultrasonic flaw detection methods have the width of the transducer divided width tabs arranged in the direction as narrow as possible (hereinafter simply referred to as width), and the width of the transducer By reducing the center-to-center spacing to the ultrasonic wavelength b or similar, grating lobes that occur during ultrasonic transmission and reception can be suppressed, and by increasing the number of tones of the transducer, side lobes can also be suppressed. I have to.

Conventionally, in order to solve the above-mentioned problems, a large number of transducers must be arranged with high precision, with intervals of 1n or less, and in order to ensure an appropriate probe aperture area. There is a need to.

Therefore, the manufacturing technology for the probe is also highly dependent on know-how, and the yield rate for manufacturing the probe is not sufficiently good. Also,
It is necessary to prepare a large number of ultrasonic transmitters according to the number of transducers and as many ultrasonic receivers as necessary, and also to draw out the electrodes from each transducer from the side of the transducer array. Because of this, the structure is complicated.

On the other hand, in the conventional probe configuration as described above, since the transducers are close to each other, high voltage and arm pulse waves may wrap around when transmitting from adjacent transducers, or excitation of the transducers may occur when transmitting waves. Because the waves wrap around, the sound field directivity expected from a single oscillator becomes narrower.

For this reason, when delaying the transmission i4 pulse to each transducer in order to fully deflect the ultrasound beam, there is a problem that the ultrasound beam is not deflected sufficiently and the sound pressure level of the deflected ultrasound beam further decreases. .

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and its objects are (a) the arrangement interval of the transducers can be set to an arbitrary arrangement interval regardless of the ultrasonic wavelength; (b) the high voltage pulse (e) An object of the present invention is to provide an ultrasonic probe that can prevent unnecessary vibrations of a transducer occurring during application. (e) The structure can be simplified.

[Summary of the invention]

In order to achieve the above object, in the present invention, grating lobes and side lobes during ultrasonic transmission and reception mainly occur when the waveform of the transmitted ultrasonic wave is close to a continuous wave, and when the waveform of the transmitted ultrasonic wave is close to a continuous wave. Focusing on the fact that these inconvenient acoustic noises do not occur, (,) the transducer width is set to approximately 14 of the total ultrasonic wavelength (b) flexible sound absorbing material is inserted between each transducer (c) each It is characterized in that the electrodes of the vibrator are taken out from a surface that intersects with the side surface of the entire vibrator array.

[Embodiments of the invention]

An embodiment of the present invention shown in the drawings will be described below.

FIG. 1(,) is a diagram showing an example of the configuration of an array type ultrasonic probe according to the present invention, and FIG. 1(b) is a diagram showing the entire peripheral configuration of one transducer in FIG. 1(a) in detail. It is.

In the figure, a play-type ultrasonic probe 1 has n ultrasonic transducers 2 (1) to 2 with minute widths (approximately -about the ultrasonic wavelength).
(n)' are arranged continuously, and a coating material 3 is applied to the sound wave transmitting/receiving surface, and a backing material 4 is closely adhered to the back surface to suppress reverberation sound when the transducer is excited and when the sound wave is received. and configure. In addition, each of the above-mentioned vibrators 2(1) to
2(n) is a flexible sound absorbing material 5 with good sound wave absorption efficiency.
is inserted and configured in close contact with the vibrators 2(1) to 2(n).

Here, as the sound absorbing material 5, a rubber material with high sound absorbing properties is used. On the other hand, one side of the electrode 6 of each vibrator 2(1) to 2(n) is a common electrode, and the other side is attached to each vibrator, but in this example, the sonic wave transmitting/receiving surface of the vibrator Common electrode 6a on the side
and the electrodes 6b(1) to 6b(
n,), and the common electrode 6a is directly connected to the signal line 7a, p,
Further, each electrode 6b(1) to 6b(n) is connected to the vibrator 2(1) to
2(n), the signal lines 7b(J) to 7b(n) are routed between the backing blades 4 from the upper surface of the transducer and from the surface intersecting with the side surface of the pick-up transducer array. It's being taken out.

Next, each feature of the array type ultrasonic probe 1 configured as described above will be described in detail.

First, the first feature is that, as mentioned above, the transducers are arranged at arbitrary intervals regardless of the total ultrasonic wavelength. According to the conventional continuous wave ultrasonic waveform, the directivity of the sound field E(
It is expressed by the Nokoshita formula.

Here, λ is the ultrasonic wavelength, nilθ0 is the number of transducers, the arrangement interval between the transducer centers, the ultrasonic beam deflection angle, and E is the sound field directivity of the transducers as shown in Fig. 2. It shows.

According to the above formula, when the ultrasonic beam is deflected by 00 degrees, the transducer spacing d is such that grating lobes do not occur.
The condition for is given by the following equation.

λ However, if the ultrasonic waveform is a single pulse wave as shown in FIG. 3(b), which is different from the continuous wave ultrasonic waveform shown in FIG. I won't take it all. This is because in the case of a continuous wave wave, as shown in the same figure (, ), the second and subsequent waves generated from each oscillator interfere with each other, creating a grating lobe, whereas in the case of a single pulse wave wave, This is because the wave height values of the second and subsequent waves are very small and the interference effect is small.

On the other hand, the smaller the width of the transducer, the wider the waves transmitted from the transducer.9 The ultrasonic deflection performance improves, but in order to improve the ultrasonic transmission and reception sensitivity, it is better to have a larger area in front of the transducer. good. For this reason, it is desirable to increase the number of transducers and reduce the transducer width to b', but the method of manufacturing the transducers and the configuration of the ultrasonic transceiver are complicated and difficult. Therefore, in this example, when transmitting waves from one vibrator, waves s (a) and ti (b) from the vicinity of both ends of the vibrator are separated as shown in Fig. 4, depending on the wave transmission direction, and the force is increased. The selection is made using the following formula to prevent noise from interfering with the sound pressure of the transmitted wave and reducing the sound pressure of the transmitted wave.

In other words, if the maximum deflection angle ψ that uses all the transmitted waves from each transducer during ultrasonic beam deflection is given, phase interference will occur at both ends of one transducer with a maximum distance deviation of . The distance deviation in the value is substantially smaller, and practically sufficient characteristics can be obtained. It should be noted that the same effect as the above-mentioned effect during wave transmission can be obtained during wave reception by the - vibrator.

Next, as mentioned above, the second feature is that the flexible sound absorbing material 5 is inserted between each of the vibrators 2(1) to 2(n) and is in close contact with each vibrator. be.

Generally, when a vibrator is excited with a high voltage pulse, various vibration modes are excited in the vibrator. As a result, in addition to the originally desired vibration mode of the transducer, such as thickness vibration, lateral vibration and the like are generated as unnecessary noise during ultrasonic wave transmission. However, in this example, in order to suppress this unnecessary vibration, the vibrator 2 (1
In addition to tightly adhering the upper and lower surfaces of the vibrators 20) to 2(n), that is, the coating material 3 and the backing material 4, a sound absorbing material 5 is inserted between each vibrator 20) to 2(n). Therefore, width vibrations of the vibrators 2(1) to 2(n) and electrical and acoustic influences between adjacent vibrators can be eliminated. Further, since the sound absorbing material 5 is flexible, it is possible to make contact with the curved surface of the probe, which has been considered difficult in the past, and the applicability to flaw detection is greatly improved.

Next, the third feature is the electrode extraction structure. In other words, while conventionally the electrodes of the vibrator were taken out from the side surface of the entire vibrator array as described above, in this example, the backing is taken out from the top surface of the vibrator 2(1) to 2(n) that intersects with the side surface. Electrode signal lines yb(1) to 7b(n) run through the entire material 4.
Since the probe is taken out, the structure of the probe can be simplified.

Furthermore, since the method for attaching the electrodes 6a, 6b to the vibrators 2(1) to 2(n) is easy, the yield in manufacturing the probes can be greatly improved.

Note that the present invention is not limited to the above embodiments.

(1) In the above, the coating material 3 is a single plate common to each vibrator, but the mechanical strength in the arrangement direction between each vibrator is greatly improved by inserting the sound absorbing material 5. It is also possible to attach the coating layer 3 or the backing material 4 to each vibrator as shown in FIG. in this case,
The common electrode 6a uses a flexible electrical conductor;
Alternatively, it can be satisfied by connecting with a crossover line. According to this example, the curved surface following deformation of the probe is even better, and flaw detection of curved surface shapes is also facilitated.

(2) In the above, the electrode signal line is taken out from the top surface of the vibrator, but it is also possible to take it out from the side surface of the vibrator array if necessary.

(3) In the above, the sound absorbing material 5 is inserted between all of the vibrators, but the same effect can be obtained by inserting the sound absorbing material 5 between some of the vibrators or between some of the vibrators. Further, unnecessary vibrations can be suppressed even if the material inserted between the vibrators does not have sound absorbing properties or flexibility.

(4) In the above, the transducer arrangement intervals are uniform, but the present invention can also be applied to transducer arrangement relationships that are uneven.

(5) In the above, a rubber material is used as the sound absorbing material, but a member made of a material such as a soft resin can also be used as long as it has high sound absorbing properties. Furthermore, by surface-treating the side surfaces of the vibrators in advance, the rubber-like sound absorbing material can be poured between the vibrators in a viscous state and brought into sufficient contact with the vibrators. This makes it possible to improve the mechanical strength of each vibrator, resulting in extremely high practicality. Note that the backing material can also be formed integrally when inserting the sound absorbing material, and the manufacturing process can also be shortened.

In addition, the present invention can be implemented with various modifications without changing the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, the arrangement interval of the transducers can be set to an arbitrary arrangement interval regardless of the total ultrasonic wavelength, and unnecessary vibrations of the transducer that occur when high voltage pulses are applied can be reduced. It is possible to provide an ultrasonic probe with a simple configuration that can suppress

[Brief explanation of the drawing]

Fig. 1 (,) (b) is a block diagram showing one embodiment of the present invention, Fig. 2 is a diagram for explaining the present invention in detail, and Fig. 3 (
, ) (b) is a diagram showing the shape of an ultrasonic wave, FIG. 4 is a schematic diagram of an ultrasonic generation situation generated from one transducer, and FIG. 5 is a configuration diagram showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Array type ultrasonic probe, 2... Ultrasonic transducer, 3... Coating material, 4... Backing layer, 5
...Sound absorbing material, 6...Electrode, 7...Signal line, 8...
・Ultrasound. Applicant's agent Patent attorney Suzue Takehikokan 1N Building 211

Claims (3)

[Claims] (1) A plurality of ultrasonic transducers are arranged continuously, a coating material is applied to the acoustic wave transmitting/receiving surface of the transducer, and a backing material is closely adhered to the surface opposite to the acoustic wave transmitting/receiving surface of the transducer, thereby enabling electronic scanning. 1. An array-type ultrasonic probe for use in ultrasonic flaw detection, characterized in that the width of each of the ultrasonic transducers in the array direction is approximately -wavelength of the ultrasonic wavelength. (2) A plurality of ultrasonic transducers are arranged continuously, a coating material is applied to the acoustic wave transmitting/receiving surface of the ultrasonic transducer, and a backing material is closely adhered to the surface opposite to the acoustic wave transmitting/receiving surface of the transducer. In an array type ultrasonic probe used for type ultrasonic flaw detection, the width in the arrangement direction of each of the ultrasonic transducers is approximately 14 wavelengths of ultrasonic wavelengths, and there is a flexible structure between each of the ultrasonic transducers. An ultrasonic probe characterized by completely inserting sound absorbing material. (3) A plurality of ultrasonic transducers are arranged continuously, a coating material is applied to the acoustic wave transmitting/receiving surface of the transducer, and a backing material is closely adhered to the surface opposite to the acoustic wave transmitting/receiving surface of the vibrator. In an array type ultrasonic probe used for type ultrasonic flaw detection, the width of each ultrasonic transducer in the array direction is approximately 17.5 mm of the total ultrasonic wavelength. A flexible sound absorbing material is inserted between each of the ultrasonic transducers, and the electrodes of each transducer are taken out from a surface that intersects with a side surface of the transducer array. probe.