JP2003302388A - Ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an ultrasonic probe which can reduce a surface echo and which can obtain a result of an accurate ultrasonic test. <P>SOLUTION: The ultrasonic probe comprises a transmitting piezoelectric transducer 1 for converting an electric signal into an acoustic signal according to an inverse piezoelectric effect; a transmitting acoustic delay material 2 provided in contact with the transducer 1; a receiving piezoelectric transducer 3 for converting the acoustic signal into the electric signal according to a piezoelectric effect; a receiving acoustic delay material 4 provided in contact with the transducer 3; and an acoustic isolation plate 5 sandwiched between the transducer 1 and the material 2 and between the transducer 3 and the material 4 so as to separate the transducer 1 and the material 2, and the transducer 3 and the material 4. The probe further comprises a sound absorbing material 6 as an end echo absorption means provided at an outside face of the material 2 or the material 4 at an opposite side to the plate 5. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe used as a sensor when performing inspection or measurement using ultrasonic waves. In particular, the present invention relates to a two-transducer probe that has a transmission oscillator and a reception oscillator separately and performs transmission and reception separately.

[0002]

2. Description of the Related Art Conventionally, regarding this type of ultrasonic probe, for example, "Ultrasonic flaw detection test II", edited by Japan Nondestructive Inspection Association, published by Japan Nondestructive Inspection Association, Heisei 6
It is described in detail on April 15th, 1990, Issue 8 edition, page 34 to page 45 (hereinafter referred to as "reference A"). FIG. 9 is a diagram showing a conventional ultrasonic probe described in Document A. In FIG. 9, 1 is a transmitting oscillator, 2 is a transmitting acoustic delay material, 3 is a receiving oscillator, 4
Is an acoustic delay material for reception, and 5 is an acoustic separator. Moreover, 7 is a contact medium layer, and 8 is a test body.

The operation of a conventional ultrasonic probe of this type will be described with reference to FIG. Although not shown in FIG. 9, the transmitting transducer 1 and the receiving transducer 3 are connected to the ultrasonic flaw detector via a probe cable. A pulsed electric signal is transmitted from the ultrasonic flaw detector to the transducer 1 for transmission.
Be transmitted to. The transmitting oscillator 1 expands and contracts due to the inverse piezoelectric effect to generate an acoustic signal. Here, for simplification, this acoustic signal will be described as "ultrasonic wave".

The ultrasonic wave generated by the transmitting vibrator 1 propagates in the transmitting acoustic delay material 2 and then propagates in the contact medium layer 7. Part of the ultrasonic waves in the couplant layer 7 propagates into the test body 8. On the other hand, the acoustic separator 5 is provided in order to eliminate the ultrasonic waves directly propagating from the transmitting acoustic delay material 2 into the receiving acoustic delay material 4, but the acoustic medium 5 is multiplexed in the contact medium layer 7. It is not possible to eliminate all the ultrasonic waves propagating in the form of reflection, and a part of the ultrasonic wave propagates in the form of multiple reflection in the couplant medium layer 7.

The ultrasonic wave propagated in the test body 8 is
When there is a flaw inside, the flaw is reflected by this flaw, and a part of the reflected wave returns to the direction of the contact medium layer 7. In addition, the reflected wave reflected by the bottom surface of the test body 8 is also the contact medium layer 7
Come back in the direction of. A part of the reflected wave reflected by the flaw or the bottom surface of the test body 8 and the wave propagating in the form of multiple reflection in the couplant layer 7 propagates in the receiving acoustic delay member 4 and these The wave is converted into an electric signal by the piezoelectric effect in the receiving vibrator 3. The ultrasonic flaw detection is performed by receiving the electric signal with the ultrasonic flaw detector.

[0006]

The above is the operation and configuration of the conventional ultrasonic probe of this type. In the ultrasonic probe of this configuration, as described above, the contact medium layer 7
There are ultrasonic waves that propagate in the form of multiple reflections, and these are echoes called "surface echoes". Since the surface echo is received even when there is no flaw in the test body 8, there is a problem that it becomes a disturbing echo in the actual ultrasonic flaw detection test and deteriorates the flaw detection test result. As means for reducing this surface echo, Japanese Patent Laid-Open No. 4-12
In Japanese Patent No. 2854, a method is used in which an acoustic separator is sandwiched between metal and nonmetal, and the joint surface is made uneven. However, this method complicates the manufacture of acoustic separators. Further, this method cannot eliminate the ultrasonic waves propagating in the contact medium layer 6 in the form of multiple reflection.

Further, as a conventional technique for suppressing unnecessary waves,
JP-A-2001-66294, JP-A-59-125
There are techniques proposed in Japanese Laid-Open Patent Publication No. 549, Japanese Patent Laid-Open No. 7-120439 and the like. However, these conventional techniques cannot reduce the surface echo unique to the two-transducer vertical probe.

As described above, in the conventional ultrasonic probe of this type, there is a surface echo which is propagated in the couplant layer 7 in the form of multiple reflections and is received. Then, there is a problem that the result of the ultrasonic flaw detection test is deteriorated. In the present invention, it is possible to reduce surface echoes without complicating the structure of the acoustic separator as in Japanese Patent Laid-Open No. 4-122854, and to obtain accurate ultrasonic flaw test results. The purpose is to obtain a sound wave probe.

[0009]

An ultrasonic probe according to the present invention is provided in contact with a transmitting oscillator for converting an electric signal into an acoustic signal by an inverse piezoelectric effect and a transmitting oscillator. Block-shaped acoustic delay material for transmission, a transducer for converting acoustic signals into electrical signals by the piezoelectric effect, and a block-shaped acoustic delay for reception provided in contact with the transducer for reception. Ultrasonic probe provided with a material, and a transducer for transmission and an acoustic delay material for transmission, and an acoustic separator sandwiched so as to separate the transducer for reception and the acoustic delay material for reception In the child, end echo absorbing means is provided on the outer surface opposite to the acoustic separator of either the transmitting acoustic delay material or the receiving acoustic delay material.

The end echo absorbing means is a sound absorbing material attached to the outer surface of the transmitting acoustic delay material or the receiving acoustic delay material.

Further, the end echo absorbing means is formed on the outer surface of the acoustic delay material for transmission or the acoustic delay material for reception, and has irregularities having an amplitude as large as the wavelength of the propagating ultrasonic wave. It has a concavo-convex shape.

Further, the end echo absorbing means is formed on the outer surface of the acoustic delay material for transmission or the acoustic delay material for reception, and has irregularities having an amplitude of the same magnitude as the wavelength of the propagating ultrasonic wave. And the sound absorbing material provided so as to cover the uneven shape.

The end echo absorbing means is provided on the outer side surfaces of both the transmitting acoustic delay material and the receiving acoustic delay material.

Further, the end echo absorbing means provided on the outer surface of either the acoustic delay material for transmission or the acoustic delay material for reception has the same size as the wavelength of the propagating ultrasonic wave. The end echo absorbing means, which has a concavo-convex shape with irregularities in amplitude and is provided on the other outer surface of the transmitting acoustic delay material or the receiving acoustic delay material, is a sound absorbing material.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a diagram showing a first embodiment of an ultrasonic probe according to the present invention. The ultrasonic probe of the present embodiment will be described with reference to FIG. The ultrasonic probe of the present embodiment includes a transmission oscillator 1 that converts an electrical signal into an acoustic signal by an inverse piezoelectric effect, and a transmission acoustic delay member 2 that contacts the transmission oscillator 1. , A receiving transducer 3 for converting an acoustic signal into an electrical signal by a piezoelectric effect, a receiving acoustic delay member 4 in contact with the receiving transducer 3, a transmitting transducer 1 and a transmitting acoustic The acoustic delay plate 2 and the receiving oscillator 3 and the acoustic delay member 4 for reception are provided so as to be separated from each other. Then, a sound absorbing material 6 as an end echo absorbing means is attached to the outer surface of the receiving acoustic delay material 4.

Next, the operation of the ultrasonic probe of the present invention will be described with reference to FIGS. FIG. 2 is a diagram for explaining the mechanism by which a surface echo is generated in a conventional probe of this type. FIG. 3 is a diagram in which the mechanism of generation of surface echo is confirmed by simulation. FIG. 4 is a diagram showing echoes obtained by the simulation of FIG. FIG. 5 is a diagram for explaining the effect of the sound absorbing material 6 shown in FIG.

As shown in FIG. 2, the ultrasonic wave propagating through the contact medium layer 7 in the form of multiple reflection is received by the acoustic delay member 4 for reception.
It is considered that a surface echo is received because an end echo starting from the tip of the surface where the sound isolator 5 and the acoustic isolator 5 contact each other is generated, and the receiving echo 3 receives this end echo. To be

In FIG. 3, in order to confirm that the end echo is the cause of the surface echo, the transmitting acoustic delay member 2,
Receiving acoustic delay material 4, couplant layer 7, and test body 8
The result of simulating the sound field inside is shown. In FIG. 3, 4.3 μsec (a) and 5.3 μse after the ultrasonic wave is generated by electrically exciting the transmitting oscillator 1
The sound fields after c (b) and after 6.3 μsec (c) are shown. As can be seen from the sound field simulation result after 6.3 μsec (c), an end echo originating from the tip of the surface where the receiving acoustic delay member 4 and the acoustic separator 5 contact each other is generated. You can see how it looks.

FIG. 4 is an echo obtained by the sound field simulation of FIG. From FIG. 4, the surface echo is received earlier than the bottom echo. In comparison with the sound field simulation result of FIG. 3, it can be seen that the surface echo shown in FIG. 4 is caused by the end echo shown in FIG.

FIG. 5 is a diagram for schematically explaining the effect of the sound absorbing material 6 shown in FIG. As shown in FIG. 5, the end echo propagates through the receiving acoustic delay material 4 and is directly received by the receiving transducer 3. However, the wall surface of the receiving acoustic delay material 4 is also present. Some components are reflected and received by. If the sound absorbing member 6 is provided outside the receiving acoustic delay member 4 in the ultrasonic wave propagation direction (on the side opposite to the acoustic separating plate 5 of the receiving acoustic delay member 4), this reflected wave is absorbed. As a result, the end echo can be suppressed. Therefore, by providing the sound absorbing material 6 outside the receiving acoustic delay material 4, there is an effect that the height of the surface echo can be reduced.

The material of the sound absorbing material 6 is an elastic body having a predetermined softness, and as a material which can be easily obtained, for example, rubber or the like is used, but the material is not limited to rubber.

Although the case where the sound absorbing material 6 is provided outside the receiving acoustic delay material 4 has been described here, the sound absorbing material 6 may be provided outside the transmitting acoustic delay material 2. Also in this case, the same effect is obtained. Further, the sound absorbing material 6 may be provided both outside the receiving acoustic delay material 4 and outside the transmitting acoustic delay material 2. In this case, the same effect is obtained.

Embodiment 2. Next, the configuration of the ultrasonic probe according to the second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing the configuration of the probe as in FIG. Unlike the first embodiment, the sound absorbing material 6 is not provided. Instead, the acoustic delay material for reception 4
The outer surface of the is made uneven 4a. The size of the irregularities should be about the same as the wavelength of the propagating ultrasonic wave. The uneven shape 4a constitutes end echo absorbing means for absorbing end echo.

Next, the operation of the ultrasonic probe of this embodiment will be described. As in the case of the first embodiment, the ultrasonic waves propagated in the couplant layer 7 in the form of multiple reflection are
When reaching the tip of the surface where the receiving acoustic delay member 4 and the acoustic separator 5 contact, an end echo is generated. The end echo propagates through the receiving acoustic delay material 4 and is directly received by the receiving transducer 3, but is reflected by the wall surface of the receiving acoustic delay material 4 and received. There are also ingredients. Therefore, the outer surface of the receiving acoustic delay member 4 has an uneven shape 4 formed by unevenness having an amplitude of the same magnitude as the wavelength of the ultrasonic wave.
If it is a, this reflected wave is attenuated and reduced in the uneven shape 4a. As a result, the end echo can be suppressed. Therefore, the height of the surface echo can be reduced by forming the outer surface of the receiving acoustic delay member 4 into the uneven shape 4a having an amplitude of the same magnitude as the wavelength of the ultrasonic wave.

In the present embodiment, the case where the outer surface of the receiving acoustic delay material 4 has the uneven shape 4a has been described, but the outer surface of the transmitting acoustic delay material 2 may have the uneven shape. . Also in this case, the same effect is obtained. Furthermore, the outer surface of the receiving acoustic delay member 4 and the transmitting acoustic delay member 2
Both of the outer side surfaces may be uneven. Also in this case,
It has the same effect.

Embodiment 3. Next, the configuration of the ultrasonic probe according to the third embodiment of the present invention will be described with reference to FIG. FIG. 7 is a diagram showing the configuration of the probe as in FIGS. 1 and 6. Unlike the first and second embodiments, a concavo-convex shape 4a is formed on the outer surface of the transmitting acoustic delay material 4, and the sound absorbing material 6 is further provided thereon. The size of the unevenness of the uneven shape 4a is about the same as the wavelength of the propagating ultrasonic wave.

Next, the operation of the ultrasonic probe according to this embodiment will be described. As in the case of the second embodiment, the ultrasonic waves propagating in the form of multiple reflection in the couplant layer 7 reach the tip of the contact surface between the receiving acoustic delay member 4 and the acoustic separator 5. When reached, an edge echo occurs.
The end echo propagates through the receiving acoustic delay material 4 and has a component directly received by the receiving transducer 3,
There is also a component which is reflected by the wall surface of the receiving acoustic delay member 4 and received. Since the outer surface of the receiving acoustic delay member 4 has the uneven shape 4a having the same size as the wavelength of the ultrasonic wave and the sound absorbing member 6 is provided thereon, the reflected wave can be further reduced. As a result, the end echo can be suppressed. With such a configuration, there is an effect that the height of the surface echo can be further reduced.

In the present embodiment, the case where the outer surface of the receiving acoustic delay member 4 has the uneven shape 4a and the sound absorbing member 6 is further provided thereon is described.
The outer surface of the acoustic delay member 2 for transmission may have an uneven shape 4a, and the sound absorbing member 6 may be further provided thereon. Also in this case, the same effect is obtained. Further, both the outer surface of the reception acoustic delay material 4 and the outer surface of the transmission acoustic delay material 2 may have the uneven shape 4a, and the sound absorbing material 6 may be further provided thereon. Also in this case, the same effect is obtained.

Fourth Embodiment Next, the configuration of the ultrasonic probe according to the fourth embodiment of the present invention will be described with reference to FIG. FIG. 8 is a diagram showing the configuration of the probe as in FIGS. 1, 6 and 7. Unlike the first, second and third embodiments, the sound absorbing material 6 is provided on the outer side of the transmitting acoustic delay material 4, and the outer side of the receiving acoustic delay material has the uneven shape 4a. The size of the unevenness is set to be about the same as the wavelength of the propagating ultrasonic wave.

Next, the operation of the ultrasonic probe according to this embodiment will be described. As in the case of the second embodiment, the ultrasonic waves propagating in the form of multiple reflection in the couplant layer 7 reach the tip of the contact surface between the receiving acoustic delay member 4 and the acoustic separator 5. When reached, an edge echo occurs.
The end echo propagates through the acoustic delay material for reception,
Some components are directly received by the receiving transducer 3, but some components are reflected by the wall surface of the receiving acoustic delay member 4 and received. Since the outer surface of the reception acoustic delay member 4 has the uneven shape 4a having the same size as the wavelength of the ultrasonic wave to reduce the reflected wave, the end echo can be suppressed as a result.

Further, in the present embodiment, since the sound absorbing material 6 is provided outside the transmitting acoustic delay material 2, in the case where the outer surface of the receiving acoustic delay material 4 is simply the uneven shape 4a. Than that, there is an effect that the height of the surface echo can be further reduced.

Here, the case where the sound absorbing material 6 is provided outside the transmitting acoustic delay material 2 and the outer surface of the receiving acoustic delay material 4 has the uneven shape 4a has been described, but the transmitting acoustic delay material 2 is described. The sound absorbing material 6 may be provided on the outer side of the receiving acoustic delay material 4 by making the outer surface of the concave and convex shape 2. Also in this case, the same effect is obtained.

[0033]

The ultrasonic probe according to the present invention has a transmitting oscillator for converting an electrical signal into an acoustic signal by the inverse piezoelectric effect, and a block-like oscillator provided in contact with the transmitting oscillator. An acoustic delay material for transmission, a receiving oscillator that converts an acoustic signal into an electrical signal by a piezoelectric effect, a block-shaped acoustic delay material for receiving provided in contact with the receiving oscillator, In an ultrasonic probe provided with a trust oscillator and an acoustic delay material for transmission, and an acoustic isolator sandwiched so as to separate the transducer for reception and the acoustic delay material for reception, Since the end echo absorbing means is provided on the outer surface on the side opposite to the acoustic separator of either the acoustic delay member for reception or the acoustic delay member for reception, the end echo can be reduced. . Therefore, the surface echo can be reduced without complicating the structure of the acoustic separator, and the ultrasonic probe can obtain an accurate ultrasonic flaw detection test result.

Further, since the end echo absorbing means is a sound absorbing material attached to the outer surface of the transmitting acoustic delay material or the receiving acoustic delay material, the end echo absorbing means has a simple structure. It can be configured, and the end echo can be reduced without increasing the cost.

Further, the end echo absorbing means is formed on the outer surface of the transmitting acoustic delay material or the receiving acoustic delay material and has irregularities having an amplitude of the same magnitude as the wavelength of the propagating ultrasonic wave. Since it has a concavo-convex shape, it is possible to configure the end echo absorbing means without requiring an additional member, and it is possible to reduce the end echo without increasing the cost.

Further, the end echo absorbing means is formed on the outer surface of the acoustic delay material for transmission or the acoustic delay material for reception, and has irregularities with an amplitude of the same magnitude as the wavelength of propagating ultrasonic waves. Since the concave-convex shape and the sound-absorbing material provided so as to cover the concave-convex shape can further reliably reduce the end echo, and further reduce the surface echo.

Further, since the end echo absorbing means is provided on the outer surface of both the transmitting acoustic delay material and the receiving acoustic delay material, the transmitting acoustic delay material and the receiving acoustic delay material. It is possible to reduce the end echo propagating to both of the delay materials. Therefore, it is possible to provide an ultrasonic probe that can obtain a more accurate ultrasonic flaw detection test result.

Furthermore, the end echo absorbing means provided on the outer surface of either the acoustic delay material for transmission or the acoustic delay material for reception has the same size as the wavelength of the propagating ultrasonic wave. Since the end echo absorbing means provided on the other outer surface of the transmitting acoustic delay material or the receiving acoustic delay material is a sound absorbing material, it has a simple structure. The end echo propagating to both the transmitting acoustic delay material and the receiving acoustic delay material can be reduced. Therefore, it is possible to provide an ultrasonic probe that can obtain a more accurate ultrasonic flaw detection test result without increasing the cost.

[Brief description of drawings]

FIG. 1 is a first embodiment of an ultrasonic probe according to the present invention.
FIG.

FIG. 2 is a diagram for explaining a mechanism of generating a surface echo.

FIG. 3 is a diagram in which a mechanism of generating a surface echo is confirmed by simulation.

FIG. 4 is a graph showing echoes obtained by the simulation of FIG.

FIG. 5 is a diagram for explaining the effect of the sound absorbing material shown in FIG.

FIG. 6 is a second embodiment of the ultrasonic probe according to the present invention.
FIG.

FIG. 7 is a third embodiment of the ultrasonic probe according to the present invention.
FIG.

FIG. 8 is a fourth embodiment of the ultrasonic probe according to the present invention.
FIG.

FIG. 9 is a diagram illustrating a conventional ultrasonic probe.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 transmitting oscillator, 2 transmitting acoustic delay material, 3 receiving oscillator, 4 receiving acoustic delay material, 4a uneven shape (end echo absorbing means), 5 acoustic isolation plate, 6 sound absorbing material (end Part echo absorption means).

Continued front page    (72) Inventor Shuzo Waka             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 2G047 BA03 CA01 EA04 GA01 GB03                       GB22                 5D019 AA22 BB21 FF04 GG11

Claims (6)

[Claims] 1. A transmission oscillator for converting an electrical signal into an acoustic signal by an inverse piezoelectric effect, a block-shaped transmission acoustic delay member provided in contact with the transmission oscillator, and a piezoelectric effect. A transducer for converting an acoustic signal into an electrical signal by means of a block, a block-shaped acoustic delay material for reception provided in contact with the transducer for reception, the transducer for transmission and the acoustic for transmission Ultrasonic probe provided with an acoustic delay plate and an acoustic isolating plate sandwiched so as to separate the receiving oscillator and the receiving acoustic delay member, the transmitting acoustic delay An ultrasonic probe characterized in that an end echo absorbing means is provided on an outer surface of the material or the receiving acoustic delay material opposite to the acoustic separator. 2. The end echo absorbing means is a sound absorbing material attached to the outer surface of the transmitting acoustic delay material or the receiving acoustic delay material. The ultrasonic probe described. 3. The end echo absorbing means has the same size as the wavelength of a propagating ultrasonic wave formed on the outer surface of the transmitting acoustic delay material or the receiving acoustic delay material. The ultrasonic probe according to claim 1, wherein the ultrasonic probe has an uneven shape with unevenness in amplitude. 4. The end echo absorbing means has the same size as the wavelength of a propagating ultrasonic wave formed on the outer surface of the transmitting acoustic delay material or the receiving acoustic delay material. The ultrasonic probe according to claim 1, wherein the ultrasonic probe is an uneven shape having unevenness of amplitude and a sound absorbing material provided so as to cover the uneven shape. 5. The end echo absorbing means is provided on the outer side surfaces of both the transmitting acoustic delay material and the receiving acoustic delay material. The ultrasonic probe according to any one. 6. The end echo absorbing means provided on the outer surface of either the acoustic delay material for transmission or the acoustic delay material for reception has the same level as the wavelength of the propagating ultrasonic wave. It is an uneven shape consisting of unevenness of amplitude of size,
The supersonic wave absorbing member according to claim 5, wherein the end echo absorbing means provided on the other outer surface of the transmitting acoustic delay material or the receiving acoustic delay material is the sound absorbing material. Sonic probe.