JP4271898B2 - Ultrasonic flaw detection apparatus and ultrasonic flaw detection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ultrasonic flaw detection apparatus and an ultrasonic flaw detection method for nondestructively inspecting a flaw in a solid. In particular, the present invention relates to an ultrasonic flaw detection apparatus and an ultrasonic flaw detection method for inspecting a probe and a test body in a non-contact manner by propagating ultrasonic waves in the air.
[0002]
[Prior art]
Conventionally, this type of non-contact flaw detection method is described in, for example, “Inspection Technology”, June 2000, pages 46 to 50 (hereinafter referred to as “Document A”).
[0003]
A conventional ultrasonic flaw detector will be described with reference to the drawings. FIG. 5 is a diagram for explaining a conventional aerial ultrasonic flaw detection method cited from Document A.
[0004]
In FIG. 5, 1 is a probe for transmission, 5 is a test body, and 11 is a probe for reception.
[0005]
Next, the operation of the conventional ultrasonic flaw detector will be described with reference to the drawings.
[0006]
Although not shown in FIG. 5, a driving device for driving the probe is connected to the transmission probe 1 via a probe cable, and a signal is sent from the driving device. The credit probe 1 is driven and ultrasonic waves are emitted into the air.
[0007]
Much energy of this ultrasonic wave is reflected on the surface of the test body 5, but part of it is transmitted into the test body 5. The transmitted ultrasonic wave passes through the test body 5 when there is no scratch in the test body 5, propagates again into the air, and is then received by the receiving probe 11.
[0008]
On the other hand, when there is a flaw in the test body 5 and this flaw is on the ultrasonic wave propagation path, the ultrasonic wave is reflected by the flaw, so the ultrasonic wave does not reach the reception probe 11 and is received. Not.
[0009]
That is, the transmitting probe 1 and the receiving probe 11 are scanned within a predetermined range, and when an ultrasonic wave is received, it is determined that there is no flaw. If no ultrasonic wave is received, the portion is flawed. Judge that there is.
[0010]
Note that a flaw detection method in which transmission is performed by ultrasonic waves and reception is performed by a laser displacement meter is also described in, for example, Japanese Patent Application Laid-Open No. 61-169759. However, the method described in this publication does not describe the case of flaw detection over a wide range, and does not describe the scanning method.
[0011]
Japanese Patent Application Laid-Open No. 64-26147 discloses a method in which a pulse laser is used to generate ultrasonic waves in a specimen and reception is performed using a laser. There is no description about flaw detection, and there is no description about the scanning method.
[0012]
[Problems to be solved by the invention]
In the conventional ultrasonic flaw detector as described above, when inspecting a wide range, it is necessary to simultaneously scan the transmitting probe 1 and the receiving probe 11, and scanning of the probe requires time. There was a problem that it took.
[0013]
The present invention has been made to solve the above-mentioned problems. An ultrasonic probe is used for transmission, a laser displacement meter is used for reception, and a probe is used to inspect a specimen over a wide range. It is an object of the present invention to obtain an ultrasonic flaw detection apparatus and an ultrasonic flaw detection method that can save time and trouble of scanning a receiving probe by scanning a probe and a laser beam.
[0015]
[Means for Solving the Problems]
In the ultrasonic flaw detector according to claim 1 of the present invention, an ultrasonic wave is transmitted to the air based on a drive signal from the probe driving device, and the incident angle of the ultrasonic wave with respect to the back surface of the test specimen is critical. a converging probe irradiates the following oblique angle, a laser oscillator for irradiating a laser beam of visible light to the surface which is opposite to the back surface of the specimen in which the ultrasonic wave is incident, the focusing-type feeler A scanning mechanism that changes the direction in which the ultrasonic wave propagates so that the child is mechanically swung and scanned over a predetermined range on the back surface of the specimen; and a propagation direction of the laser beam of the visible light In other words, a laser beam scanning that electrically scans a predetermined range of the surface of the specimen so that a surface of the specimen opposite to the back surface of the specimen on which the ultrasonic wave is incident is irradiated with a visible laser beam. and the mechanism part, A part of the ultrasonic wave irradiated obliquely with an incident angle below the critical angle with respect to the back surface of the test specimen is refracted and transmitted through the test specimen, and propagates through the test specimen to be the surface of the test specimen. reached, to vibrate the surface of the specimen, in which a laser displacement meter for measuring the vibrations of it.
[0022]
In the ultrasonic flaw detection method according to claim 2 of the present invention, an ultrasonic wave is transmitted to the air based on a driving signal from a probe driving device by a converging probe, and the ultrasonic wave is transmitted to the back surface of the specimen. Irradiating a laser beam of visible light to a surface opposite to the back surface of the test body on which the ultrasonic wave is incident by a laser oscillator and a transmission step of irradiating obliquely with an incident angle equal to or less than a critical angle And a probe that changes the direction in which the ultrasonic wave propagates so that the focusing probe is mechanically swung scanned by the scanning mechanism unit over a predetermined range on the back surface of the specimen. and child scanning step, the laser by the beam scanning mechanism, by changing the propagation direction of the laser beam of the visible light, a laser beam of visible light to the opposite side in a surface of the back surface of the specimen in which the ultrasound is incident A laser beam scanning step of electrically scanned over a predetermined range of the surface of the specimen so as to morphism, a laser displacement meter, an incident angle with respect to the back surface of the specimen is irradiated to the following oblique critical angle some of the ultrasonic wave transmitted refracted in the specimen, and propagating in the specimen reaches the surface of the specimen, to vibrate the surface of the specimen, the measurement step of measuring the vibration of its Is included.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
An ultrasonic flaw detector according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration of an ultrasonic flaw detector according to Embodiment 1 of the present invention. In addition, in each figure, the same code | symbol shows the same or equivalent part.
[0029]
In FIG. 1, 1 is a transmission probe, 2 is a laser oscillator, 3 is a laser beam, 4 is a laser displacement meter, 5 is a test body, and 6 is a surface of the test body 5 on the side of the transmission probe 1 (hereinafter referred to as a probe). , 7 is referred to as the back surface of the test body 5), 7 is a surface of the test body 5 on the laser oscillator 2 side (hereinafter referred to as the front surface of the test body 5), 8 is a scratch in the test body 5, and 9 is a transmission probe. This is a scanning mechanism unit for scanning the touch element 1. The laser oscillator 2 includes a scanning mechanism that electrically scans the laser beam 3 (not shown).
[0030]
Next, the operation of the ultrasonic flaw detector according to Embodiment 1 will be described with reference to the drawings.
[0031]
FIG. 2 is a diagram showing an operation state of the ultrasonic flaw detector according to Embodiment 1 of the present invention.
[0032]
Although not shown, a probe driving device is connected to the transmission probe 1 via a probe cable, and an electric drive signal is transmitted from the probe driving device to the transmission probe 1. To be applied. In the transmission probe 1, an ultrasonic wave is emitted in the air by this drive signal, and the ultrasonic wave propagates toward the back surface 6 of the test body 5.
[0033]
Most of the ultrasonic energy that propagates in the air and reaches the back surface 6 of the test body 5 is reflected, but a part of the energy is transmitted into the test body 5. The transmitted ultrasonic wave propagates through the test body 5. As shown in FIG. 1, when the scratch 8 is on the ultrasonic wave propagation path in the test body 5 and the size of the scratch 8 is larger than the beam width of the ultrasonic wave propagating through the test body 5, Ultrasound is reflected.
[0034]
On the other hand, a laser beam 3 is irradiated from the laser oscillator 2 to a portion on the opposite side of the portion where the ultrasonic wave generated by the transmission probe 1 is incident on the test body 5. When the ultrasonic wave is reflected by the scratch 8, the ultrasonic wave has no effect on the surface 7 of the test body 5, so that nothing is measured by the laser displacement meter 4.
[0035]
Subsequently, as shown in FIG. 2, the transmission probe 1 is scanned in the direction along the back surface 6 of the test body 5 by the scanning mechanism unit 9. When the transmitting probe 1 reaches a place where there is no flaw 8, the ultrasonic wave propagated through the test body 5 reaches the surface 7 of the test body 5. Then, the surface 7 of the test body 5 is vibrated.
[0036]
On the other hand, the electric scanning mechanism provided in the laser oscillator 2 changes the propagation direction of the laser beam 3 and is opposite to the place where the ultrasonic wave generated by the transmitting probe 1 is incident on the specimen 5. The laser beam 3 is irradiated on the surface. In this case, since the surface 7 of the test body 5 is vibrating, the vibration of the surface 7 of the test body 5 can be measured by the laser displacement meter 4.
[0037]
When the transmission probe 1 is scanned by the scanning mechanism unit 9, the laser beam 3 is scanned by the scanning mechanism unit provided in the laser oscillator 2, and the vibration distribution of the surface 7 of the specimen 5 is measured, Since no vibration is measured at a certain place, the scratch 8 can be detected. Further, if the transmitting probe 1 and the laser beam 3 are scanned over a wide range, the place where the flaw 8 is present can be specified. In this way, the test body 5 can be inspected.
[0038]
When the test body 5 is inspected with the configuration and operation described above, the following effects are obtained. That is, since the mechanical scanning is performed only by the transmission probe 1 that generates ultrasonic waves, the scanning is simpler than the conventional apparatus configured to perform transmission and reception by the probe, and a large test specimen is obtained. When inspecting, inspection time can be greatly shortened.
[0039]
In addition, if a focusing probe is used as the transmission probe 1 and a large ultrasonic wave is generated in the test body 5, the S / N ratio is improved.
[0040]
Furthermore, if the laser beam 3 is made visible, the position on the surface 7 of the test body 5 that is being inspected can be seen with the eyes, so that the apparatus can be set quickly. As a result, it is possible to further reduce the inspection time.
[0041]
Embodiment 2. FIG.
An ultrasonic flaw detector according to Embodiment 2 of the present invention will be described with reference to the drawings. FIG. 3 is a diagram showing the configuration of the ultrasonic flaw detector according to Embodiment 2 of the present invention.
[0042]
In FIG. 3, the basic configuration is the same as that of the first embodiment, but the operation of the scanning mechanism 9 of the transmission probe 1 is different.
[0043]
Next, the operation of the ultrasonic flaw detector according to Embodiment 2 will be described with reference to the drawings.
[0044]
Unlike the first embodiment, the scanning mechanism unit 9 is used to swing the transmission probe 1 to swing.
[0045]
By this scanning, the ultrasonic wave emitted from the transmission probe 1 is incident obliquely on the back surface 6 of the test body 5, but if the incident angle is less than the critical angle, a part of the ultrasonic wave is in the test body 5. The light is refracted and transmitted through the test body 5.
[0046]
If there is no scratch 8 on the propagation path, the ultrasonic wave reaches the surface 7 of the test body 5 and vibrates the surface 7 of the test body 5. If this vibration is measured by the laser displacement meter 4 as in the first embodiment, the presence / absence of the scratch 8 and the position of the scratch 8 can be obtained.
[0047]
When ultrasonic waves are incident obliquely on the back surface 6 of the test body 5, longitudinal waves and transverse waves propagate in the test body 5, but either wave may be used for inspection.
[0048]
If the scanning of the transmission probe 1 is swung as described above, the size of the scanning mechanism 9 can be reduced as shown in FIG. 3, so that in addition to the effect shown in the first embodiment, a narrow place But there is an effect that can be inspected.
[0049]
Similarly to the first embodiment, if a focusing probe is used as the transmission probe 1 and a large ultrasonic wave is generated in the test body 5, the SN ratio is improved.
[0050]
Furthermore, if the laser beam 3 is made visible, the position on the surface 7 of the test body 5 that is being inspected can be seen with the eyes, so that the apparatus can be set quickly. As a result, it is possible to further reduce the inspection time.
[0051]
Embodiment 3 FIG.
An ultrasonic flaw detector according to Embodiment 3 of the present invention will be described with reference to the drawings. FIG. 4 is a diagram showing a configuration of an ultrasonic flaw detector according to Embodiment 3 of the present invention.
[0052]
In FIG. 4, the configuration is almost the same as in the first and second embodiments, but the configurations and operations of the transmission probe 1 and the scanning mechanism unit 9 are different. The transmission probe 1 is an array and can be driven for each channel. Further, a control device 10 for driving each channel separately is connected to the transmission probe 1.
[0053]
Next, the operation of the ultrasonic flaw detector according to Embodiment 3 will be described with reference to the drawings.
[0054]
A signal for separately driving each channel of the transmission probe 1 is applied from the control device 10. The control device 10 controls the timing of driving each channel, thereby changing the propagation direction of the ultrasonic wave emitted from the transmission probe 1. That is, the transmission probe 1 is electrically scanned like a phased array.
[0055]
The ultrasonic wave emitted from the transmission probe 1 is obliquely incident on the back surface 6 of the test body 5. If the incident angle is less than the critical angle, a part of the ultrasonic wave is refracted into the test body 5. And propagates through the specimen 5.
[0056]
If there is no scratch 8 on the propagation path, the ultrasonic wave reaches the surface 7 of the test body 5 and vibrates the surface 7 of the test body 5. If this vibration is measured by the laser displacement meter 4 as in the first embodiment, the presence / absence of the scratch 8 and the position of the scratch 8 can be obtained.
[0057]
When ultrasonic waves are incident obliquely on the back surface 6 of the test body 5, longitudinal waves and transverse waves propagate in the test body 5, but either wave may be used for inspection.
[0058]
Thus, if the scanning of the transmission probe 1 is electrically scanned, there is an effect that the inspection time can be further shortened compared with the mechanical scanning. Further, since the scanning mechanism unit 9 is not required, there is an effect that inspection can be performed even in a narrow place in addition to the effect shown in the first embodiment.
[0059]
In addition to controlling the timing of driving each channel of the transmission probe 1 by the control device 10, not only changing the propagation direction of the ultrasonic wave, but also focusing the ultrasonic wave causes a large amount in the specimen 5. Ultrasound can be generated. As a result, there is an effect that the SN ratio is improved.
[0060]
Furthermore, if the laser beam 3 is made visible, the position on the surface 7 of the test body 5 that is being inspected can be seen with the eyes, so that the apparatus can be set quickly. As a result, it is possible to further reduce the inspection time.
[0062]
【The invention's effect】
As described above, the ultrasonic flaw detector according to claim 1 of the present invention transmits ultrasonic waves to the air based on the drive signal from the probe drive device, and transmits the ultrasonic waves to the back surface of the specimen. A converging probe that irradiates obliquely with an incident angle equal to or less than a critical angle, a laser oscillator that irradiates a laser beam of visible light to a surface opposite to the back surface of the test body on which the ultrasonic wave is incident, A scanning mechanism that mechanically swings and scans the focusing probe so as to scan over a predetermined range on the back surface of the specimen, and a laser that emits visible light and changes the direction in which the ultrasonic wave propagates; The beam propagation direction is changed, and a laser beam of visible light is irradiated over a predetermined range of the surface of the test body so as to irradiate the surface opposite to the back surface of the test body on which the ultrasonic wave is incident. Scanning laser Propagation and over arm scanning mechanism, the angle of incidence with respect to the rear surface of the test body is a part of the ultrasonic waves radiated to the following oblique critical angle passes refracted in the specimen, through the said test body to reach the surface of the specimen, to vibrate the surface of the specimen, since a laser displacement meter for measuring the vibrations of its, if scanning is simplified, to inspect a large specimen, test time Can be greatly shortened, and there is an effect that inspection can be performed even in a narrow place.
[0070]
In the ultrasonic flaw detection method according to the second aspect of the present invention, as described above, the ultrasonic wave is transmitted to the air based on the drive signal from the probe driving device by the focusing probe and the ultrasonic wave is detected. A laser beam of visible light with respect to the surface opposite to the back surface of the test body on which the ultrasonic wave is incident by a laser oscillator. The ultrasonic wave is propagated so that the focusing probe is mechanically swung and scanned over a predetermined range on the back surface of the specimen by an irradiation step of irradiating a beam and a scanning mechanism unit. a probe scanning step changes direction, the laser beam scanning mechanism, wherein by changing the propagation direction of the visible light laser beam, visible to said surface ultrasonic waves is opposite to the back surface of the test body incident Oblique of the laser beam scanning step of electrically scanned over a predetermined range of the surface of the specimen so as to irradiate the laser beam, the laser displacement meter, the incident angle is less than the critical angle with respect to the back surface of the specimen some of ultrasonic waves radiated is transmitted refracted in the test specimen, and propagates through the said test body reaches to the surface of the specimen, to vibrate the surface of the test body, the oscillation of its Since it includes a measurement step for measuring, scanning is simplified, and when inspecting a large specimen, the inspection time can be greatly shortened, and the inspection can be performed even in a narrow place.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of an ultrasonic flaw detector according to Embodiment 1 of the present invention.
FIG. 2 is a diagram showing an operation state of the ultrasonic flaw detector according to Embodiment 1 of the present invention.
FIG. 3 is a diagram showing a configuration of an ultrasonic flaw detector according to Embodiment 2 of the present invention.
FIG. 4 is a diagram showing a configuration of an ultrasonic flaw detector according to Embodiment 3 of the present invention.
FIG. 5 is a diagram showing a configuration of a conventional ultrasonic flaw detector.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Probe for transmission, 2 Laser oscillator, 3 Laser beam, 4 Laser displacement meter, 5 Test body, 6 Back surface, 7 Surface, 8 Scratches, 9 Scanning mechanism part, 10 Control apparatus.

Claims (2)

A focusing probe that transmits ultrasonic waves into the air based on a driving signal from the probe driving device and irradiates the ultrasonic waves obliquely with an incident angle of less than a critical angle with respect to the back surface of the specimen;
A laser oscillator for irradiating a laser beam of visible light to a surface opposite to the back surface of the test body on which the ultrasonic wave is incident;
A scanning mechanism that changes the direction in which the ultrasonic wave propagates so that the focusing probe is mechanically swung and scanned over a predetermined range of the back surface of the specimen;
Wherein changing the propagation direction of the visible light of the laser beam, the ultrasonic wave is the specimen back surface of the to the surface which is opposite to the visible laser beam a predetermined surface of the specimen so as to irradiate the incident A laser beam scanning mechanism that electrically scans a range;
A part of the ultrasonic wave irradiated obliquely with an incident angle below the critical angle with respect to the back surface of the test body is refracted and transmitted through the test body, and propagates through the test body to be the surface of the test body. until reaching, by vibrating the surface of the specimen, an ultrasonic flaw detection apparatus characterized by comprising a laser displacement meter for measuring the vibrations of it. Based on the driving signal from the probe driving device, the focusing probe transmits ultrasonic waves to the air and irradiates the ultrasonic waves obliquely with the incident angle below the critical angle on the back of the specimen. Sending step;
An irradiation step of irradiating a laser beam of visible light onto a surface opposite to the back surface of the test body on which the ultrasonic wave is incident by a laser oscillator,
A probe scanning step for changing the direction in which the ultrasonic wave propagates so that the focusing probe is mechanically swung and scanned over a predetermined range on the back surface of the specimen by a scanning mechanism. When,
The laser beam scanning mechanism unit changes the propagation direction of the visible light laser beam so that the surface that is opposite to the back surface of the test body on which the ultrasonic wave is incident is irradiated with the visible light laser beam. A laser beam scanning step for electrically scanning a predetermined area of the surface of the specimen;
A laser displacement meter refracts and transmits a part of the ultrasonic wave irradiated obliquely with an incident angle below the critical angle with respect to the back surface of the test body, and propagates through the test body. A measurement step of reaching the surface of the test body, vibrating the surface of the test body, and measuring the vibration;
An ultrasonic flaw detection method comprising:

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