JP2000146921A - Method and device for ultrasonic crack detection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method and device for ultrasonic crack detection for realizing traverse wave oblique angle crack detection without using any wedge. SOLUTION: This device is provided with plural vertical wave vibrators arranged like an array directly or through a contact medium on the surface of an object 13 to be inspected and ultrasonic transmitting means 9, 15, and 16 for generating and making incident ultrasonic horizontal waves to an oblique direction in the object 13 to be inspected according to a vertical stress generated by exciting each of those plural vertical wave vibrators 10 through a delay time for transmission controller 6T equipped with time differences corresponding to the arranged positions or exciting it by a pulser group 7 with transmitting power weighting equipped with the time differences corresponding to the arranged positions for executing weighting so that the distribution of a transmitting power within the arranged positions can be turned into desired distribution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates generally to a nondestructive inspection technique, and more particularly to a method and an apparatus for performing oblique flaw detection using a shear wave.

[0002]

2. Description of the Related Art An oblique flaw detection method using ultrasonic waves, particularly a flaw detection method using transverse waves of ultrasonic waves, has been widely used as a means for inspecting flaws in welds of bridges, shipbuilding, pipelines and the like.

FIG. 5 is a view showing stress transmission in shear wave oblique flaw detection. In oblique flaw detection of ultrasonic waves, regardless of longitudinal waves and transverse waves, as shown in FIG. 5, an ultrasonic transducer is attached to a wedge having a predetermined angle, and ultrasonic waves are transmitted and received obliquely through the wedge. We are performing flaw detection. Further, in the oblique flaw detection using a shear wave, the flaw detection is usually performed by making only the shear wave incident on the inspection object using mode conversion at the boundary surface between the wedge and the inspection object. In angle beam flaw detection using a transverse wave using an array probe, for example, Japanese Patent Application Laid-Open No.
As shown in JP-A-58-58, etc., a method is used in which an array probe is attached to a wedge having an inclination with respect to a flaw detection contact surface, and a transverse wave is obliquely incident to perform flaw detection.

FIG. 7 is an explanatory view of shear wave oblique flaw detection using a conventional array probe. In FIG. 7, reference numeral 1 denotes a transducer for transmitting and receiving ultrasonic waves, and a plurality of transducers are arranged on the inclined surface of the wedge 2 in an array at a predetermined interval. 3 is a damper material, 6 is a delay time control device including a plurality of delay time variable elements for controlling the delay time at the time of transmission and at the time of reception for each of a plurality of transducers, and 5 is for each of the plurality of transducers An ultrasonic pulser / receiver group that supplies a transmission pulse via a variable delay time element and inputs and amplifies a reception signal. Numeral 11 denotes an incident transverse wave mode-converted at the boundary between the wedge 2 and the inspection object 13.

[0005] By controlling the delay time of each variable delay element in the delay time control device 6 using the apparatus configured as shown in FIG. Flaw detection can be performed by transmitting and receiving in an oblique direction.

[0006]

As described above, in the prior art as well, in oblique flaw detection using a transverse wave, a method of transmitting and receiving ultrasonic waves in an oblique direction using a wedge is performed.
However, in this method, the attenuation in the wedge due to the longer transmission distance in the wedge, the attenuation difference caused by the difference in the transmission distance of the ultrasonic waves emitted from each transducer, and the wedge angle due to the wear of the contact surface of the probe. Problems caused by using a wedge, such as a change in the refraction angle due to the change and an unnecessary echo due to the reflection of the ultrasonic wave in the wedge, have occurred. In addition, due to the reflection caused by the difference in the characteristic impedance between the wedge material and the test material, the sensitivity of transmitting and receiving waves was significantly reduced. Further, when a wedge is used in an array probe in which a large number of elements are arranged, there is a problem that the angle probe becomes large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and it has been made possible to perform shear wave oblique flaw detection without using a wedge, and to use various methods such as attenuation of ultrasonic waves based on the use of a wedge. It is an object of the present invention to provide an ultrasonic flaw detection method and apparatus capable of forming a small and compact apparatus which has no problem, has a high detection accuracy with a simple configuration, and is compact.

[0008]

According to a first aspect of the present invention, there is provided an ultrasonic flaw detection method, wherein a plurality of vertical longitudinal wave vibrators are arranged in an array on a subject surface directly or via a couplant. A plurality of vertical longitudinal wave vibrators are excited with a time difference according to the arrangement position, or a time difference according to the arrangement position is provided, and the distribution of the transmission power within the arrangement position is desired. Ultrasonic transverse waves are generated and incident in an oblique direction in the subject by vertical stress generated by weighting and exciting them so as to form a distribution.

According to a second aspect of the present invention, there is provided an ultrasonic flaw detection method, wherein a plurality of vertical longitudinal wave transducers for both transmission and reception are arranged in an array on the surface of a subject directly or through a couplant. A plurality of vertical longitudinal wave oscillators for dual use are excited with a time difference according to the arrangement position, or the transmission power distribution in the arrangement position is provided with a time difference according to the arrangement position. Are generated by weighting and exciting them so as to have a desired distribution, thereby generating ultrasonic transverse waves in an oblique direction in the subject, entering the ultrasonic transverse waves, and reflecting ultrasonic transverse waves from the subject. Is received by each of the plurality of vertical longitudinal oscillators that are also used for transmitting and receiving, and these received outputs are combined with a time difference according to the arrangement position of the receiving oscillator. Or the time difference according to the installation position Provided and distribution of the signal amplification factor in the arrangement position synthesizes each output obtained by amplifying by weighting each so that the desired distribution is for a receiving outputs the combined signal.

According to a third aspect of the present invention, there is provided an ultrasonic flaw detection method, wherein a plurality of vertical longitudinal wave oscillators for transmitting and a plurality of vertical longitudinal wave oscillators for receiving a wave are directly or through a couplant. Transducers are arranged in an array, respectively, and the plurality of vertical longitudinal wave oscillators for transmitting waves are excited with a time difference according to the arrangement position, or the time difference according to the arrangement position is excited. And by generating a transverse stress in the oblique direction in the subject by the vertical stress generated by weighting and exciting each of the transmission power distributions in the arrangement position so that the distribution becomes a desired distribution. The vertical stress based on the ultrasonic transverse wave which is incident and reflected from the inside of the subject is received by each of the plurality of vertical longitudinal wave oscillators for receiving, and the received output of each of these is received. Whether to combine them with a time lag depending on the location of the Each output obtained by providing a time difference according to the arrangement position and weighting and amplifying the signal amplification factor distribution in the arrangement position to obtain a desired distribution is combined, and the combined signal is obtained. Is the reception output.

The ultrasonic flaw detection method according to a fourth aspect of the present invention is the ultrasonic flaw detection method according to the second or third aspect, wherein the plurality of vertical longitudinal wave vibrators for both transmitting and receiving or transmitting waves are excited. The time difference provided in accordance with the arrangement position of each of the excitation vibrators is controlled by controlling the time difference so that the beam direction of the incident ultrasonic transverse wave generated in an oblique direction in the subject is set to a desired angle direction. In addition, the time difference provided depending on the arrangement position of each of the receiving transducers when receiving by the plurality of vertical longitudinal transducers for both transmitting and receiving or receiving is different from the desired flaw detection in the subject. The time difference is controlled so that the received wave composite output based on the ultrasonic transverse wave reflected from the angular direction is maximized.

According to a fifth aspect of the present invention, there is provided an ultrasonic flaw detector, comprising: a plurality of vertical longitudinal wave vibrators arranged in an array on the surface of a subject directly or via a couplant; The wave oscillator is excited by providing a time difference according to its arrangement position, or by providing a time difference according to the arrangement position and so that the distribution of transmission power in the arrangement position becomes a desired distribution. And ultrasonic transmitting means for generating ultrasonic transverse waves in the oblique direction in the subject by a vertical stress generated by weighting and exciting the ultrasonic waves and entering the ultrasonic waves.

According to a sixth aspect of the present invention, there is provided an ultrasonic flaw detector, comprising: a plurality of transmitting / receiving vertical longitudinal wave vibrators disposed in an array on the surface of a subject directly or via a couplant; A plurality of vertical longitudinal wave vibrators that also serve as waves are excited by providing a time difference according to the arrangement position, or a time difference is provided according to the arrangement position, and transmission power within the arrangement position is reduced. Ultrasound transmitting means for generating and incident ultrasonic transverse waves in an oblique direction in the subject by vertical stress generated by weighting and exciting the distribution so that the distribution becomes a desired distribution, and from the inside of the subject. The vertical stress based on the reflected ultrasonic shear wave is received by each of the plurality of vertical longitudinal wave vibrators serving both as the transmitting and receiving waves, and the respective received wave outputs are output.
The receiving oscillator is synthesized by providing a time difference according to the arrangement position, or the time difference according to the installation position is provided and the distribution of the signal amplification factor in the arrangement position becomes a desired distribution. Thus, the outputs obtained by weighting and amplifying the respective signals are combined, and an ultrasonic wave receiving means for using the combined signal as a reception output is provided.

According to a seventh aspect of the present invention, there is provided an ultrasonic flaw detector, comprising: a plurality of vertical longitudinal wave oscillators for transmitting a wave; A plurality of vertical longitudinal wave oscillators, and a plurality of vertical longitudinal wave oscillators for the transmission, the excitation is provided with a time difference according to the arrangement position, or the time difference according to the installation position The ultrasonic wave is generated in a diagonal direction in the subject by the vertical stress generated by the weighting and the excitation, so that the distribution of the transmission power in the arrangement position becomes a desired distribution. Ultrasonic transmission means, and receives a vertical stress based on the ultrasonic transverse wave reflected from the subject by the plurality of vertical longitudinal wave transducers for the transmission, respectively, these received wave output, A time difference is provided according to the position of the Or combining the outputs obtained by providing a time difference according to the arrangement position and weighting and amplifying the signal amplification factor distribution in the arrangement position so as to have a desired distribution. And ultrasonic receiving means for receiving the synthesized signal as a reception output.

An ultrasonic flaw detector according to an eighth aspect of the present invention is the ultrasonic flaw detector according to the sixth or seventh aspect, wherein the plurality of vertical longitudinal wave vibrators for both transmitting and receiving waves or transmitting waves are excited. The time difference provided in accordance with the arrangement position of each excitation vibrator at the time of performing the process is such that the time difference is generated so that the beam direction of the incident ultrasonic transverse wave generated in an oblique direction in the subject is set to a desired angle direction. Along with the control, the time difference provided according to the arrangement position of each of the wave receiving vibrators when receiving by the plurality of vertical longitudinal wave vibrators for both transmitting and receiving or receiving wave is a desired time difference in the subject. There is a transmission and reception time difference control means for controlling the time difference so that the received wave composite output based on the ultrasonic transverse wave reflected from the flaw detection angle direction is maximized.

The ultrasonic flaw detector according to a ninth aspect of the present invention is the ultrasonic flaw detector according to the sixth aspect, wherein a plurality of vertical longitudinal wave transducers for transmitting and receiving waves arranged in an array are integrated. This is configured as an array probe for both transmission and reception.

An ultrasonic flaw detector according to a tenth aspect of the present invention is the ultrasonic flaw detector according to the seventh aspect, wherein the plurality of vertical longitudinal wave oscillators for transmitting waves, which are respectively arranged in an array, are provided. A plurality of vertical longitudinal wave transducers for receiving, only a plurality of vertical longitudinal wave transducers for receiving and a plurality of vertical longitudinal wave transducers for receiving are used. This is configured as an integrated wave receiving array probe.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is a new technique which does not use a conventional wedge in oblique flaw detection by a shear wave using a plurality of vertical longitudinal wave transducers or an array probe in which these are integrated. First, the outline and principle of the present invention will be described. FIG. 5 is an explanatory view of stress transmission in the shear wave oblique flaw detection according to the present invention, and FIG. 6 is an explanatory view of a difference between a case where a conventional wedge is used and an arrangement position of a vibrator in the present invention.

As shown in the enlarged view of the lower part of FIG. 5, in the oblique flaw detection, ultrasonic waves are incident on the inspection object via the couplant. Since the couplant is usually a liquid such as machine oil, no shear stress is transmitted, and only the stress perpendicular to the flaw detection contact surface is transmitted to the inspection object. Similarly, as for the reflected wave of the ultrasonic wave from the flaw or the like in the inspection object, only the stress perpendicular to the flaw detection contact surface is transmitted to the wedge. Therefore, as shown in FIG. 6, the wedge when performing the oblique flaw detection using a plurality of transducers has a function of slightly giving a time difference to the vertical stress generated from each of the plurality of transducers and transmitted to the flaw detection contact surface. Will be. Therefore, even if a wedge is not used, by setting the time difference of the vertical stress applied to the flaw detection contact surface to be the same as the time difference when the wedge is used, it is possible to detect the shear wave at an oblique angle.

Further, the ultrasonic beam formed by each normal stress from the plurality of transducers has directivity. Therefore, when simultaneously exciting a plurality of transducers without using a wedge, the center portion of the arrangement position is strengthened, and both ends are weakly weighted and excited, so that an arbitrary directivity pattern (for example, Shape with reduced side lobes).

As described above, shear wave oblique flaw detection can be performed without using a wedge by controlling the time difference and weighting of the vertical stress applied to the flaw detection contact surface during oblique flaw detection. The control of the time difference and the weighting of the vertical stress can be performed only on the transmitting side of the ultrasonic wave, or can be performed on both the transmitting side and the receiving side. Further, on either side, the control of the time difference and the weighting need not necessarily be both, and may be only the control of the time difference. The arrangement example of the vibrator according to the present invention in FIG. 6 shows an example in which a plurality of vertical longitudinal wave vibrators for both transmitting and receiving waves are arranged in an array on the surface of the subject directly or via a couplant. Hereinafter, in the arrangement example of the vibrator according to the present invention in FIG. 6, a method of controlling the time difference and weighting at the time of transmission and a method of controlling the time difference and weighting at the time of reception will be described.

In the example of the arrangement of the vibrators according to the present invention shown in FIG. 6, the control on the transmitting side includes, for example, the timing of exciting each of a plurality of vertical longitudinal wave vibrators arranged in an array for both transmitting and receiving waves. Control, and a time difference corresponding to the arrangement position is provided to sequentially excite, or a time difference according to the arrangement position is provided, and the distribution of the transmission power in the arrangement position becomes a desired distribution. Each is weighted and excited. Then, a transverse ultrasonic wave is generated and incident in an oblique direction in the subject by vertical stress generated by excitation of the plurality of transducers (usually, repeated excitation of a burst wave or the like at regular intervals).

In the arrangement example of the vibrator according to the present invention shown in FIG. 6, the control on the receiving side may be, for example, a method in which a vertical stress based on an ultrasonic transverse wave reflected from the inside of the subject is applied to the plurality of transmitting / receiving waves. Received by each vertical longitudinal oscillator,
These received wave outputs are synthesized by providing a time difference according to the arrangement position of the wave receiving oscillator, or by providing a time difference according to the arrangement position and using a receiver within the arrangement position. The outputs obtained by weighting and amplifying the respective signals so that the distribution of the signal amplification factor becomes a desired distribution are combined, and the combined signal is used as a reception output. There are two control methods on the transmission side and two control methods on the reception side. Therefore, when control is performed on both the transmission side and the reception side, there are four control methods. .

Embodiment 1 In Embodiment 1, an example is shown in which a plurality of vertical longitudinal wave transducers for both transmission and reception are used, and the time difference and weight control are performed on both the transmission side and the reception side. FIG. 1 is a configuration diagram of an ultrasonic flaw detector according to Embodiment 1 of the present invention. In FIG. 1, 10
Numeral denotes a plurality of n vertical wave oscillators for both transmitting and receiving waves, which are arranged in an array at predetermined intervals on the surface of the inspection object 13 directly or via a couplant. Reference numerals 6T and 6R denote delay time control devices for transmission and reception, respectively.
Each of the delay times at the time of reception includes n delay time variable elements that are individually controlled. Note that, in the example of FIG. 1, each of the delay time variable elements includes
3,... #N, the respective delay times t ₁ , t ₂ ,
t ₃ ... t _n are controlled by the control device 9 so as to decrease sequentially and to generate a predetermined time difference. Therefore, the time difference Δt = t ₁ −t ₂ = t ₂ −t ₃ =... Between the delay times is constant.

Numeral 7 in FIG. 1 denotes a transmission power weighted pulsar group. When exciting each of the vibrators, each of them is weighted and excited so that the distribution of the transmission power in the arrangement position becomes a desired distribution. Contains pulsars. For example, the transmission power is maximum at the center between the oscillators # 1 and #n,
The distribution is minimized at both ends of # 1 and #n.
Reference numeral 8 denotes a receiver amplification weighting group of receivers, and when amplifying the received signal received by each transducer, weighting and amplifying the signal so that the distribution of the signal amplification factor in the arrangement position becomes a desired distribution. N receivers. For example, the distribution may be the same as the distribution of the transmission power.
The weighted and amplified n outputs are combined, and the combined signal becomes a reception output.

Reference numeral 9 denotes a control device, which includes delay times of n delay time variable elements in the transmission and reception delay time control devices 6T and 6R, transmission timing of the transmission power weighting pulser group 7, and transmission power weighting; And control of reception timing and reception amplification factor weighting of the reception amplification factor weighting receiver group. 11 is an incident transverse wave, 12 is a reflected transverse wave, 13 is an inspection object, 15 is a data processing device, and 16 is a personal computer, which controls the control device 9 and the data processing device 15.
Reference numeral 17 denotes a flaw in the inspection object 13.

Assuming that a plurality of vertical longitudinal wave oscillators 10 shown in FIG. 1 are given the same delay time as when the wedge shown in FIG. 6 is used, this delay time is obtained as follows. In the case of the shear wave oblique angle using the wedge in FIG. 6, the following equation (1) is established by the law of refraction (Snell's law).

[0028]

(Equation 1)

Where θ: shear wave refraction angle α: longitudinal wave incident angle (= wedge angle) C _S2 : shear wave velocity in the inspection object C _L1 : longitudinal wave velocity in the wedge.

As shown in FIG. 6, each of a plurality of vertical longitudinal wave vibrators is numbered # 1, # 2,... #N, and an attempt is made to generate ultrasonic transverse waves in oblique directions as shown in the figure. If
The delay time t _i given to the #i oscillator is the difference in the transmission distance in the wedge to the position of the #i oscillator on the flaw detection contact surface (n−
i) · a P · sin .alpha order corresponding to the value obtained by dividing the speed of sound C _L2 in the wedge, represented by the following formula (2).

[0031]

(Equation 2)

Here, P: arrangement pitch of transducers n: total number of transducers From the equations (1) and (2), the delay time t _i given to the vibrator #i to generate a transverse wave with a refraction angle is given by the following equation (3).

[0033]

(Equation 3)

The transmission delay time control device 6T is controlled by the control device 9 so as to give a delay time for each oscillator calculated by the equation (3) to each pulser output from the transmission power weighted pulser group 7. Similarly, the receiving delay time control device 6 </ b> R controls the receiving device to give a delay time for each of the transducers calculated by Expression (3) to a plurality of received signals received by each of the transducers. 9. as a result,
Without using a wedge, shear wave oblique flaw detection in a predetermined oblique direction in the inspection object 13 can be performed.

The control device 9 controls the delay time of each variable delay element in the transmission and reception delay time control devices 6T and 6R so that the incident angle and the reflection angle of the ultrasonic transverse wave can be adjusted in the desired angular direction. Therefore, for example, it is also possible to perform a flaw detection by a sector scan that scans a predetermined sector range by changing this angular direction little by little every time ultrasonic waves are transmitted and received.

Further, in FIG. 1, the transmission power weighting pulsar group 7 transmits each transmission signal weighted such that the distribution of the transmission power in the arrangement position of the n vibrators becomes a desired distribution. Each of the transducers is supplied with excitation via the control device 6T to perform excitation, and each of the transducers receives a reflected wave. The received signal supplied via the reception delay time control device 6R is converted into a reception amplification factor. The weighting receiver group 8 weights and amplifies the distribution of the signal amplification factors in the arrangement positions of the n transducers so as to have a desired distribution, combines the amplified outputs, and combines the amplified outputs. Is used as a receiver output signal, in addition to controlling the incident angle and reflection angle of the ultrasonic wave, it is possible to perform control so that a transmitted beam and a received beam of the ultrasonic wave can be formed as desired beams.

The control parameters required for each control can be input to the control device 9 itself, or the parameters can be transferred by a personal computer 16 connected to the control device 9.

Embodiment 2 In Embodiment 2, a plurality of vertical longitudinal wave oscillators for transmitting and a plurality of vertical longitudinal wave oscillators for receiving are used, and the time difference and weight control are performed on both the transmitting side and the receiving side. An example is shown. FIG. 2 is a configuration diagram of an ultrasonic flaw detector according to Embodiment 2 of the present invention. In the configuration of FIG. 2, a plurality of n vertical wave oscillators for transmission 10T and a plurality of vertical wave oscillators for reception n are replaced with the plurality of n vertical wave oscillators 10 for transmission and reception in FIG. 1. The difference is that the longitudinal wave vibrator 10R is used, but the other configuration is the same as that of FIG.

This is an effective flaw detection method when most of the reflected transverse waves are reflected in another direction different from the incident transverse waves due to the shape of the flaw 17. In FIG. 2, since the angle direction of the incident transverse wave is different from the direction in which the reflected transverse wave is received,
The control of the delay time of each variable delay element in the transmission delay time control device 6T and the reception delay time control device 6R is different from each other. That is, each delay time on the transmission side is controlled so that the incident angle of the ultrasonic transverse wave incident on the inspection target 13 is in a desired angle direction, and each delay time on the reception side is a desired delay time in the inspection target 13. Is controlled so that the received wave composite output based on the ultrasonic transverse wave reflected from the flaw detection direction is maximized.

Embodiment 3 Embodiment 3 shows an example in which an array probe in which a plurality of vertical longitudinal wave transducers are integrated is used. FIG. 3 is an explanatory diagram of an array probe according to Embodiment 3 of the present invention. FIG. 3A shows an example of the array probe 4 for both transmission and reception in which a plurality of vertical longitudinal wave transducers for both transmission and reception of FIG. 1 are integrated.

FIG. 3B shows a case in which the probe 14 for protecting the surface of the array probe having no inclination is attached to the array probe 4 in order to protect the surface of the array probe in the case of FIG. Is shown. Shoe 1 used in FIG.
No. 4 has no inclination, so the delay time in the shoe 14 for each transducer is uniform, and the same operation as in the first embodiment is performed.

A plurality of vertical longitudinal wave oscillators 10T for transmitting and a plurality of vertical longitudinal wave oscillators 10R for receiving the wave shown in FIG.
Is configured as an array flaw detector, only a transmitting array probe integrating only a plurality of vertical longitudinal wave transducers 10T for transmitting and a plurality of vertical longitudinal wave transducers 10R for receiving are provided. Is generally configured as an integrated wave receiving array probe.

FIG. 4 is a diagram showing an example of a flaw detection result by the ultrasonic flaw detector of FIG. FIG. 4 shows a drill having a depth of 12 mm and a diameter of 2 mm formed into a test piece having a thickness of 60 mm using an array probe having the number of transducers of 16 and the arrangement pitch of the transducers of 0.5 mm in the apparatus of FIG. An example of an A-scope waveform when a hole is inspected by setting a time difference so as to have a flaw detection angle of 45 ° and applying a stress distribution such that the center of the driving vibrator group becomes large. The horizontal axis in FIG. 4 indicates the beam path of the shear wave. Note that the delay time given to each vibrator was calculated by equation (3). FIG. 4 shows that the drill holes are detected with sufficient sensitivity.

As described above, according to the present embodiment, shear wave oblique flaw detection becomes possible without using a wedge, and ultrasonic flaw detection using a wedge as represented by a difference in attenuation of a signal in the wedge is possible. You can get rid of the problem. Further, since no wedge is used, the size of the oblique probe, particularly, the height of the probe can be reduced.

[0045]

As described above, according to the present invention, a plurality of vertical longitudinal wave oscillators are arranged in an array on the surface of an object directly or via a couplant, and the plurality of vertical longitudinal wave oscillators are arranged. Is excited by providing a time difference according to the installation position, or is provided with a time difference according to the installation position and weighted such that the distribution of the transmission power in the installation position becomes a desired distribution. The vertical stress generated by the excitation
Since an ultrasonic transverse wave is generated and incident in an oblique direction in the subject, the oblique incidence of the transverse wave becomes possible without using a wedge, and an attenuation difference caused by a difference in transmission distance of the ultrasonic wave in the conventional wedge. Can be eliminated. In addition, since the reflection due to the difference in the characteristic impedance between the wedge material and the subject material can be avoided, the sensitivity of transmitting and receiving waves can be significantly improved.

According to the present invention, a plurality of vertical longitudinal wave transducers for both transmitting and receiving are arranged in an array on the surface of the subject directly or via a couplant, and the plurality of vertical longitudinal transducers for both transmitting and receiving are arranged. The wave oscillator is excited with a time difference according to the arrangement position, or is provided with a time difference according to the arrangement position, and the distribution of the transmission power in the arrangement position is a desired distribution. The ultrasonic stress is generated by weighting and exciting each, and an ultrasonic transverse wave is generated and incident in an oblique direction in the subject, and the vertical stress based on the ultrasonic transverse wave reflected from the subject is transmitted and received. Waves are received by a plurality of vertical longitudinal wave vibrators that also serve as waves, and these received wave outputs are combined with a time difference according to the position where the wave receiving vibrator is disposed, or With a time difference according to Each output obtained by weighting and amplifying the distribution of the signal amplification factor in the device to obtain a desired distribution is combined, and the combined signal is used as a reception output, so that no wedge is used. The shear wave oblique flaw detection becomes possible, the attenuation difference caused by the difference in the ultrasonic transmission distance in the conventional wedge, the change in the refraction angle due to the change in the wedge angle due to the wear of the contact surface of the transducer, and the ultrasonic wave in the wedge Various problems such as generation of unnecessary echo due to reflection can be eliminated.

Further, according to the present invention, a plurality of vertical longitudinal wave oscillators for transmitting and a plurality of vertical longitudinal wave oscillators for receiving are arrayed on the surface of the subject either directly or through a couplant. Arranged, the shear wave oblique incidence using the plurality of vertical longitudinal wave oscillators for transmission and the reception process in an arbitrary shear wave reflection direction using the plurality of vertical longitudinal wave oscillators for reception. Therefore, it is possible to detect a flaw having a shape that cannot be detected by a plurality of vertical longitudinal wave vibrators that can also be used for transmission and reception.

Further, according to the present invention, when exciting the plurality of vertical longitudinal wave oscillators for both transmitting and receiving or transmitting, the time difference provided in accordance with the arrangement position of each of the exciting oscillators is different from that in the subject. Along with controlling the time difference so that the beam azimuth of the ultrasonic transverse wave generated and incident in an oblique direction is a desired angle direction, a plurality of vertical longitudinal wave vibrators for both transmitting and receiving waves or receiving waves are used. The time difference provided according to the arrangement position of each of the receiving transducers at the time of receiving a wave is such that the received wave combined output based on the ultrasonic transverse wave reflected from a desired flaw detection angle direction in the subject is maximized. Since the time difference is controlled, the flaw detection direction of the ultrasonic wave can be changed, and flaw detection can be performed by sector scanning in an arbitrary sector range.

Further, according to the present invention, an array probe for both transmitting and receiving is formed by integrating a plurality of vertical longitudinal wave transducers for transmitting and receiving arranged in the form of an array. Since a transmitting array probe that integrates only multiple vertical longitudinal oscillators and a receiving array probe that integrates only multiple vertical longitudinal oscillators for receiving are configured. In addition, the height of the array probe formed without using a wedge can be made smaller than in the conventional case.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an ultrasonic flaw detector according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram of an ultrasonic flaw detector according to Embodiment 2 of the present invention.

FIG. 3 is an explanatory diagram of an array probe according to a third embodiment of the present invention.

FIG. 4 is a diagram showing an example of a flaw detection result by the ultrasonic flaw detector of FIG. 1;

FIG. 5 is an explanatory view of stress transmission in shear wave oblique flaw detection according to the present invention.

FIG. 6 is an explanatory diagram showing a difference in the arrangement position of a vibrator according to the present invention when a conventional wedge is used.

FIG. 7 is an explanatory diagram of shear wave oblique flaw detection using a conventional array probe.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 vibrator 2 wedge 3 damper material 4 array probe 5 ultrasonic pulsar / receiver group 6 delay time control device 6T transmission delay time control device 6R reception delay time control device 7 transmission power weighting pulsar group 8 reception amplification factor weighting Receiver group 9 Control device 10 Vertical longitudinal wave oscillator 10T Vertical longitudinal wave oscillator for transmitting 10R Vertical longitudinal wave oscillator for receiving 11 Incident transverse wave 12 Reflected transverse wave 13 Object to be inspected 15 Data processing device 16 Personal computer 17 Flaw

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G047 BB01 BB02 CB01 CB02 DB05 EA15 GB02 GF17 GF22 GG34

Claims (10)

[Claims] 1. A plurality of vertical longitudinal oscillators are arranged in an array on the surface of an object directly or via a couplant, and the plurality of vertical longitudinal oscillators are arranged to have a time difference corresponding to the arrangement position. Provided and excited, or by providing a time difference according to the arrangement position and by vertical stress generated by weighting and exciting each so that the distribution of transmission power in the arrangement position becomes a desired distribution, An ultrasonic flaw detection method, wherein an ultrasonic transverse wave is generated in an oblique direction in the subject and is incident. 2. A plurality of vertical longitudinal wave oscillators for both transmitting and receiving waves are arranged in an array on a subject surface directly or via a couplant, and the plurality of vertical longitudinal wave oscillators for both transmitting and receiving waves are Exciting by providing a time difference according to the arrangement position, or providing a time difference according to the arrangement position and weighting each such that the distribution of transmission power in the arrangement position becomes a desired distribution. Due to the vertical stress generated by the excitation,
An ultrasonic transverse wave is generated and incident in an oblique direction in the subject, and a vertical stress based on the ultrasonic transverse wave reflected from the subject is received by each of the plurality of vertical longitudinal wave vibrators serving also as the transmitting and receiving waves. Waves are received, and each of these received outputs is synthesized by providing a time difference according to the arrangement position of the wave receiving oscillator, or by providing a time difference according to the arrangement position and within the arrangement position. An ultrasonic flaw detection method characterized by combining outputs obtained by weighting and amplifying each signal so that a distribution of a signal amplification factor becomes a desired distribution, and using the combined signal as a reception output. 3. A plurality of vertical longitudinal wave oscillators for transmitting and a plurality of vertical longitudinal wave oscillators for receiving are respectively arranged in an array on the surface of the subject directly or through a couplant. A plurality of vertical longitudinal wave oscillators for transmitting waves are excited with a time difference according to the arrangement position, or the transmission power within the arrangement position is provided with a time difference according to the arrangement position. The vertical stress generated by weighting and exciting each distribution so that the distribution becomes a desired distribution generates ultrasonic transverse waves in an oblique direction in the subject, enters the supersonic wave, and reflects the supersonic waves reflected from the subject. The vertical stress based on the transverse acoustic wave is received by each of the plurality of vertical longitudinal oscillators for receiving waves, and each of these received outputs is provided with a time difference according to the arrangement position of the received oscillator. Combining, or providing a time difference according to the arrangement position; and An ultrasonic wave characterized by combining respective outputs obtained by weighting and amplifying each signal so that a distribution of a signal amplification factor in the arrangement position becomes a desired distribution, and using the combined signal as a reception output. Flaw detection method. 4. A time difference provided in accordance with an arrangement position of each of the plurality of vertical longitudinal wave vibrators for both transmitting and receiving or transmitting waves, the time difference being provided in an oblique direction in the subject. When controlling the time difference so that the beam direction of the ultrasonic transverse wave to be generated and incident is set to a desired angle direction, and when receiving by the plurality of vertical longitudinal wave transducers for both transmitting and receiving or receiving. The time difference provided in accordance with the arrangement position of each of the wave receiving transducers is controlled such that the received wave combined output based on the ultrasonic transverse wave reflected from the desired flaw detection angle direction in the subject is maximized. 4. The method according to claim 2, wherein
The described ultrasonic flaw detection method. 5. A plurality of vertical longitudinal wave oscillators arranged in an array on a subject surface directly or via a couplant, and a time difference corresponding to the arrangement position of each of the plurality of vertical longitudinal oscillators. Or by providing a time difference in accordance with the arrangement position and by weighting and exciting the transmission power distribution in the arrangement position to have a desired distribution. And an ultrasonic transmitting means for generating and incident ultrasonic transverse waves in an oblique direction in the subject. 6. A plurality of vertical longitudinal wave oscillators both for transmitting and receiving waves and arranged in an array on the surface of a subject directly or via a couplant, and a plurality of vertical longitudinal wave oscillators for both transmitting and receiving waves. Exciting by providing a time difference according to the arrangement position, or providing a time difference according to the arrangement position and weighting the transmission power distribution within the arrangement position to be a desired distribution. Ultrasonic transmitting means for generating and incident an ultrasonic transverse wave in an oblique direction in the subject by the vertical stress generated by excitation, and the vertical stress based on the ultrasonic transverse wave reflected from within the subject. Each of the plurality of vertical longitudinal wave vibrators for both transmission and reception is received, and each of these received wave outputs is combined with a time difference according to the position where the wave receiving vibrator is provided, or Set a time difference according to the position and And ultrasonic receiving means for combining respective outputs obtained by weighting and amplifying so that the distribution of the signal amplification factor in the installation position becomes a desired distribution, and using the combined signal as a reception output. An ultrasonic flaw detector characterized by the above-mentioned. 7. A plurality of vertical longitudinal wave oscillators for wave transmission and a plurality of vertical longitudinal wave oscillators for wave reception, which are arranged in an array on the surface of the subject directly or via a couplant, respectively. A plurality of vertical longitudinal wave oscillators for transmitting waves are excited with a time difference according to the arrangement position, or the transmission power within the arrangement position is provided with a time difference according to the arrangement position. Ultrasonic transmission means for generating and incident an ultrasonic transverse wave in an oblique direction in the subject by vertical stress generated by weighting and exciting each so that the distribution becomes a desired distribution; and The vertical stress based on the ultrasonic transverse wave reflected from the ultrasonic wave is received by each of the plurality of vertical longitudinal wave oscillators for transmission, and the respective received outputs are determined according to the arrangement position of the received oscillator. To be combined with a certain time lag, or The outputs obtained by weighting and amplifying each signal so that the distribution of the signal amplification factor in the arrangement position becomes a desired distribution are provided, and the combined signal is used as a reception output. An ultrasonic flaw detector comprising an ultrasonic receiving means. 8. A time difference provided in accordance with an arrangement position of each of the plurality of vertical longitudinal wave vibrators for both transmitting / receiving and transmitting waves in the oblique direction in the subject. While controlling the time difference so that the beam azimuth of the ultrasonic transverse wave generated and incident is set to a desired angular direction, a plurality of vertical longitudinal wave vibrators for both transmitting and receiving or receiving are used. The time difference provided in accordance with the arrangement position of each wave receiving transducer controls the time difference so that the received wave combined output based on the ultrasonic transverse wave reflected from the desired flaw detection angle direction in the subject becomes maximum. The ultrasonic flaw detector according to claim 6 or 7, further comprising a time difference control unit for transmission and reception. 9. The ultrasonic probe according to claim 6, wherein said plurality of vertical longitudinal wave transducers for transmission and reception arranged in an array are integrated to constitute an array probe for transmission and reception. Sonic flaw detector. 10. A plurality of vertical longitudinal wave oscillators for wave transmission and a plurality of vertical longitudinal wave oscillators for wave reception arranged in an array, respectively. 8. The ultrasonic array probe according to claim 7, wherein said array probe is a wave receiving array probe in which only a transmitting array probe and a plurality of vertical longitudinal wave transducers for receiving are integrated. Sonic flaw detector.