KR20230035669A - Ultrasonic testing device and ultrasonic testing method - Google Patents

Abstract

Provided is an ultrasonic inspection apparatus that is excellent in detecting performance of defects, for example, in resolution of a displayed image. For this reason, the ultrasonic inspection device Z is provided with a scanning measuring device 1 that scans and measures an ultrasonic beam on an object to be inspected, and a control device 2 that controls driving of the scanning measuring device 1. , The scanning measuring device 1 includes a transmission probe 110 that emits an ultrasonic beam and an eccentrically placed receiving probe 120 that receives the ultrasonic beam, and the transmission sound axis of the transmission probe 110 and the eccentrically placed receiving probe ( The eccentrically placed receiving probe 120 is arranged so that the eccentric distance of the receiving sound axis of the receiving sound axis of 120 is greater than zero, and the control device 2 extracts the signal phase information of the ultrasonic beam received by the eccentrically placed receiving probe 120. Phase extraction A unit 231 and a phase change amount calculation unit 232 that calculates the amount of phase change related to the scanning position of the extracted phase information are provided.

Description

Ultrasonic testing device and ultrasonic testing method

The present disclosure relates to an ultrasonic inspection apparatus and an ultrasonic inspection method.

BACKGROUND OF THE INVENTION [0002] A method for inspecting a defective part of an object to be inspected using an ultrasonic beam is known. For example, when there is a defect (cavity, etc.) with a small acoustic impedance such as air inside the inspected object, an acoustic impedance gap is created inside the inspected object, so that the transmission amount of the ultrasonic beam is reduced. Therefore, by measuring the transmittance of the ultrasonic beam, it is possible to detect a defect inside the inspected object.

The technology described in Patent Literature 1 is known for an ultrasonic inspection apparatus. In the ultrasonic inspection apparatus described in Patent Literature 1, a rectangular wave burst signal composed of a predetermined number of consecutive negative square waves is applied to a transmitting ultrasonic transducer disposed facing an object under test through air. A receiving ultrasonic transducer disposed facing the subject through air converts ultrasonic waves propagating through the subject into a transmission wave signal. Based on the signal level of this transmitted wave signal, the presence or absence of a defect in the subject is determined. In addition, the transmission ultrasonic transducer and the reception ultrasonic transducer set the acoustic impedance of the vibrator and the front plate provided on the ultrasonic transmission/reception side of the vibrator lower than that of the contact type ultrasonic transducer used in contact with the object under test.

Japanese Unexamined Patent Publication No. 2008-128965 (particularly an abstract)

In the ultrasonic inspection apparatus described in Patent Literature 1, there is a problem that the resolution of an image of the observed defect portion is lowered when observing a minute defect portion in an object to be inspected. That is, there is a problem that the outline of the image corresponding to the defective part becomes blurred. This is because a change occurs in the received signal even when a part of the ultrasonic beam is blocked by the defective part. This problem becomes particularly remarkable when the size of the defect to be detected is equal to or smaller than the size of the ultrasonic beam (beam diameter).

The problem to be solved by the present disclosure is to provide an ultrasonic inspection apparatus and an ultrasonic inspection method that are excellent in detecting performance of defective parts, for example, in resolution of a displayed image.

An ultrasonic inspection device according to the present disclosure is an ultrasonic inspection device that inspects an object to be inspected by incident an ultrasonic beam on the object to be inspected through a fluid, and includes a scanning measuring device that scans and measures the ultrasonic beam onto the object to be inspected. , a control device for controlling driving of the scanning measuring device, wherein the scanning measuring device includes a transmitting probe emitting the ultrasonic beam and an eccentrically positioned receiving probe, and a transmission sound axis of the transmitting probe and the eccentrically positioned receiving probe. The eccentrically placed receiving probe is arranged so that the eccentric distance of the receiving sound axis of the probe is larger than zero;

The control device includes a phase extraction unit for extracting signal phase information of the ultrasound beam received by the eccentrically placed receiving probe, and a phase change amount calculation unit for calculating a change amount of the extracted phase information for each scanning position. It's about the device. Other solutions are described later in the form for implementing the invention.

According to the present disclosure, it is possible to provide an ultrasonic inspection device and an ultrasonic inspection method that are excellent in the detection performance of a defect part, for example, the resolution of a displayed image.

1 is a diagram showing the configuration of an ultrasonic inspection apparatus according to a first embodiment.
Figure 2a is a diagram explaining the transmission sound axis, the reception sound axis and the eccentric distance, in the case where the transmission sound axis and the reception sound axis extend in the vertical direction.
Figure 2b is a diagram explaining the transmission sound axis, the reception sound axis and the eccentric distance, in the case where the transmission sound axis and the reception sound axis extend obliquely.
3 is a cross-sectional schematic diagram showing the structure of a transmission probe.
FIG. 4A is a received waveform from an eccentrically placed receiving probe, and is a diagram showing a received waveform at a sound portion N of an object E to be inspected.
FIG. 4B is a received waveform from an eccentrically placed receiving probe, and is a diagram showing a received waveform at a defective portion D of an object E to be inspected.
5 is a diagram showing an example of a plot of signal strength data.
Fig. 6A is a diagram showing a propagation path of an ultrasonic beam in the present embodiment, when the ultrasonic beam is incident on a sound field.
Fig. 6B is a propagation path of an ultrasonic beam in the present embodiment, and is a diagram showing the case where the ultrasonic beam is incident on a defect part.
7A is a diagram showing a propagation path of an ultrasonic beam in a conventional ultrasonic inspection method, and is a diagram showing the incidence of an ultrasonic beam into a sound part.
FIG. 7B is a diagram showing a propagation path of an ultrasonic beam in a conventional ultrasonic inspection method, and is a diagram showing the incidence of an ultrasonic beam on a defect part.
8 is a diagram showing a plot of signal intensity data in a conventional ultrasonic inspection method.
FIG. 9A is a diagram illustrating an interaction between a defective part and an ultrasonic beam in an object to be inspected, and is a diagram illustrating receiving a direct ultrasonic beam.
9B is a diagram illustrating an interaction between a defect in an object to be inspected and an ultrasonic beam, and is a diagram illustrating reception of scattered waves.
10 is a functional block diagram of a control device.
Fig. 11 is a diagram schematically showing a change in a received signal of an eccentrically arranged receiving probe at each scan position in the x-axis direction.
12A is a diagram showing a scanning position where an ultrasonic beam is not incident on a defect part.
FIG. 12B is a diagram showing a scanning position where an ultrasonic beam is incident on a defective portion but a transmission sound axis does not enter the defective portion.
Fig. 12C is a diagram showing scanning positions at which an ultrasonic beam is incident on a defective portion and a transmission sound axis enters the defective portion.
13 is a diagram showing the hardware configuration of the control device.
14 is a flowchart showing the ultrasonic inspection method according to the first embodiment.
Fig. 15 is a diagram showing the configuration of an ultrasonic inspection apparatus in the second embodiment.
Fig. 16 is a functional block diagram of an ultrasonic inspection apparatus in the second embodiment.
Fig. 17 is a diagram showing the configuration of an ultrasonic inspection apparatus according to a third embodiment.
Fig. 18 is a diagram showing the configuration of an ultrasonic inspection apparatus according to a fourth embodiment.
Fig. 19 is a diagram showing the configuration of an ultrasonic inspection apparatus in a fifth embodiment.
20 is a functional block diagram of an ultrasonic inspection apparatus in a fifth embodiment.
Fig. 21 is a diagram showing the relationship between a transmission probe and an eccentrically disposed receiving probe in the ultrasonic inspection apparatus according to the sixth embodiment.
Fig. 22 is a diagram explaining the relationship between the beam incident area of a transmission probe and the beam incident area of an eccentrically placed receiving probe.
23 is a diagram showing an example of an eccentrically arranged receiving probe according to a seventh embodiment.
Fig. 24 is a diagram showing the configuration of a scanning measurement device of an ultrasonic inspection apparatus according to an eighth embodiment.
Fig. 25 is a diagram explaining the reason why the effect according to the eighth embodiment occurs.
Fig. 26 is a diagram showing the configuration of an ultrasonic inspection apparatus according to a ninth embodiment.
Fig. 27 is a functional block diagram of an ultrasonic inspection apparatus according to a ninth embodiment.
28 is a diagram showing the arrangement of eccentrically arranged receiving probes in the tenth embodiment.
Fig. 29 is a diagram showing the arrangement of eccentrically arranged receiving probes in the eleventh embodiment, in which the unit probes are arranged at an angle.
30 is a diagram showing the arrangement of eccentrically arranged receiving probes in the eleventh embodiment, and is a view in which the unit probes are arranged in the vertical direction.
Fig. 31 is a diagram showing the configuration of an ultrasonic inspection apparatus according to a twelfth embodiment.
Fig. 32 is a diagram showing the configuration of an ultrasonic inspection apparatus according to a thirteenth embodiment.
33 is a diagram showing the configuration of an ultrasonic inspection apparatus according to a fourteenth embodiment.

EMBODIMENT OF THE INVENTION Hereinafter, the form (referred to as an embodiment) for implementing this disclosure is described, referring drawings. However, the present disclosure is not limited to the following embodiments, and, for example, combinations of different embodiments or modifications can be made arbitrarily within a range not significantly impairing the effect of the present disclosure. In addition, the same code|symbol shall be attached|subjected about the same member, and overlapping description is abbreviate|omitted. In addition, the thing which has the same function shall attach the same name. The contents of the illustration are exemplary only, and for the sake of illustration, there are cases where they are changed from the actual configuration within a range that does not significantly impair the effect of the present disclosure.

(First Embodiment)

1 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a first embodiment. In FIG. 1, the scan measuring device 1 is shown in a cross-sectional schematic diagram. 1 shows an orthogonal three-axis coordinate system including an x-axis as a left-right direction of the paper, a y-axis as a direction orthogonal to the paper, and a z-axis as the up-and-down direction of the paper.

The ultrasonic inspection device Z is configured to inspect the object E to be inspected by incident an ultrasonic beam U ( FIG. 3 ) on the object E to be inspected through the fluid F. The fluid F is, for example, a liquid W such as water (FIG. 17) or a gas G such as air, and the inspected object E exists in the fluid F. In the first embodiment, air (an example of gas G) is used as the fluid F. Accordingly, the inside of the housing 101 of the scan measuring device 1 is a cavity filled with air. As shown in FIG. 1 , the ultrasonic inspection device Z includes a scanning measurement device 1 , a control device 2 , and a display device 3 . The display device 3 is connected to the control device 2 .

The scanning measuring device 1 scans and measures an ultrasonic beam U on an object E to be inspected, and has a sample table 102 fixed to a housing 101, and the sample table 102 has a sample table 102 fixed to a housing 101. (E) is loaded. The inspected object E is made of an arbitrary material. The subject E to be inspected is, for example, a solid material, more specifically, for example, a metal, glass, resin material, or a composite material such as CFRP (Carbon-Fiber Reinforced Plastics). In addition, in the example of FIG. 1, the subject E has the defect part D inside. The defective portion D is a cavity or the like. Examples of the defective portion D include a cavity, a foreign material different from the original material, and the like. In the inspected object E, parts other than the defective part D are referred to as a sound part N.

Since the defective portion D and the intact portion N are made of different materials, the acoustic impedance is different between them, and the propagation characteristics of the ultrasonic beam U change. The ultrasonic inspection apparatus Z observes this change and detects the defective part D.

The scanning measuring device 1 includes a transmitting probe 110 that emits an ultrasonic beam U and an eccentrically disposed receiving probe 120 . The transmission probe 110 is installed in the housing 101 through the transmission probe scanning unit 103 and emits an ultrasonic beam U. The eccentric arrangement receiving probe 120 is a receiving probe 121 installed on the opposite side of the transmission probe 110 with respect to the object under test E to receive the ultrasonic beam U. The eccentric arrangement receiving probe 120 has a receiving sound axis AX2 at a position different from the transmission sound axis AX1 of the transmission probe 110 . The distance between the transmission sound axis AX1 and the reception sound axis AX2 is the eccentric distance L. The eccentric arrangement receiving probe 120 is installed in the housing 101 through the receiving probe injection unit 104 .

In addition, in the present specification, among the receiving probes 121 that receive the ultrasonic beam U, those disposed at positions having an eccentric distance L greater than zero are defined as eccentrically disposed receiving probes 120, and the eccentric distance L is zero. What is disposed at the position of is defined as a coaxial arrangement receiving probe 140 (Fig. 2a, etc.). In other words, the receiving probe 121 is a term encompassing the eccentrically disposed receiving probe 120 and the coaxially disposed receiving probe 140, and is a name representing a probe that receives ultrasonic waves regardless of the eccentric distance L.

Here, "opposite side of the transmission probe 110" is a space on the opposite side (opposite side in the z-axis direction) of the space where the transmission probe 110 is located, among the two spaces partitioned by the inspected object E. It is a meaning, and it does not mean that the opposite side where the x and y coordinates are the same (namely, the position of plane symmetry with respect to the xy plane). As shown in Fig. 1, the transmitting probe 110 and the eccentrically placed receiving probe 120 are installed so that the transmission sound axis AX1 and the reception sound axis AX2 are offset by an eccentric distance L. Further, the specific contents of the transmission sound axis AX1, the reception sound axis AX2, and the eccentric distance L will be described later.

As the receiving probe scan unit 104 moves, the eccentrically placed receiving probe 120 scans the sample table 102 in the x-axis and y-axis directions. The transmitting probe 110 and the eccentrically disposed receiving probe 120 scan while maintaining the eccentric distance L with respect to the x-axis direction or the y-axis direction with the inspected object E interposed therebetween (both thick arrows).

In addition, in the scanning measuring device 1, the eccentricity distance L is set as follows, although all details will be described later. That is, the eccentricity distance L is set to a distance capable of receiving the scattered wave U1 generated by scattering of the ultrasonic beam U at the defective portion D of the object E to be inspected. Alternatively, the intensity of the received signal from the eccentrically arranged receiving probe 120 when incident on the defective part D of the object E to be inspected is greater than the intensity of the received signal when incident on the sound part N of the object E to be inspected. So, the eccentricity distance L is set. Alternatively, the eccentricity distance L is set to a distance at which received signals other than noise are not detected during irradiation of the sound portion N of the subject E.

The scanning measuring device 1 adjusts the position of at least one of the transmitting probe 110 and the eccentrically arranged receiving probe 120 so that the eccentric distance L between the transmission sound axis AX1 and the reception sound axis AX2 is greater than zero. A distance adjustment unit 105 is provided. An eccentric distance adjustment unit 105 (eccentric distance adjustment mechanism) is provided in the receiving probe injection unit 104 installed in the housing 101 . In addition, the eccentric distance adjusting unit 105 is provided with an eccentric arrangement receiving probe 120 . The eccentric distance adjusting unit 105 can move the eccentrically arranged receiving probe 120 independently from the position of the receiving probe scanning unit 104, and the difference between the receiving sound axis AX2 and the transmitting sound axis AX1 is the eccentric distance L It can be set to be this. Further, the eccentric distance adjusting unit 105 may be provided on the transmission probe scanning unit 103 side. That is, since it is only necessary to set the offset between the reception sound axis AX2 and the transmission sound axis AX1 to be the eccentricity distance L, even if the eccentricity distance adjusting unit 105 is provided on the receiving probe 121 side, the transmission probe 110 side may be provided in

A control device 2 is connected to the scanning measurement device 1 . The control device 2 controls the driving of the scanning measuring device 1, and instructs the transmission probe scanning unit 103 and the receiving probe scanning unit 104 to transmit the transmission probe 110 and the eccentric arrangement reception probe 120. ) to control the movement (scan). As the transmission probe scanning unit 103 and the receiving probe scanning unit 104 move synchronously in the x-axis and y-axis directions, the transmission probe 110 and the eccentrically placed receiving probe 120 move the inspected object E in the x-axis direction. and scan in the y-axis direction. In addition, the control device 2 emits an ultrasonic beam U from the transmission probe 110 and analyzes the waveform based on the signal obtained from the eccentrically placed receiving probe 120 .

Further, in the present embodiment, the transmission probe is in a state where the test subject E is fixed to the housing 101 via the sample stand 102, that is, the test subject E is fixed to the housing 101. An example of scanning 110 and the eccentrically placed receiving probe 120 is shown. Contrary to this, the transmission probe 110 and the eccentrically placed receiving probe 120 may be fixed to the housing 101, and scanning may be performed by moving the inspected object E.

Between the transmission probe 110 and the test subject E, and between the eccentrically placed receiving probe 120 and the test subject E, in the illustrated example, a gas G (an example of a fluid F. A liquid W ( 17)) is interposed. Because of this, since the transmission probe 110 and the eccentrically placed receiving probe 120 can be inspected without contacting the inspected object E, it is possible to change the relative positions in the xy plane directions smoothly and at high speed. That is, by interposing the fluid F between the transmitting probe 110 and the eccentrically disposed receiving probe 120 and the inspected object E, smooth scanning is possible.

The transmission probe 110 is a convergent transmission probe 110 . On the other hand, the eccentrically arranged receiving probe 120 uses a probe whose convergence is more gentle than that of the transmitting probe 110 . In this embodiment, a non-convergent type probe having a flat transducer surface is used for the eccentric arrangement receiving probe 120. By using such a non-converging eccentric arrangement receiving probe 120, it is possible to collect information on the defect part D over a wide range.

In the present embodiment, although the eccentric arrangement receiving probe 120 is displaced by the eccentric distance L in the x-axis direction of FIG. A probe 120 may be disposed. Alternatively, the eccentric arrangement receiving probe 120 is disposed at L1 in the x-axis direction and L2 in the y-axis direction (ie, when the position of the transmitting probe 110 in the xy plane is the origin, the position of (L1, L2)) It can be.

Fig. 2A is a diagram explaining the transmission sound axis AX1, the reception sound axis AX2, and the eccentric distance L, in the case where the transmission sound axis AX1 and the reception sound axis AX2 extend in the vertical direction. Fig. 2B is a diagram explaining the transmission sound axis AX1, the reception sound axis AX2, and the eccentric distance L, in the case where the transmission sound axis AX1 and the reception sound axis AX2 extend obliquely.

The negative axis is defined as the central axis of the ultrasonic beam U. Here, the transmission sound axis AX1 is defined as the sound axis of the propagation path of the ultrasonic beam U emitted by the transmission probe 110. In other words, the transmission sound axis AX1 is the central axis of the propagation path of the ultrasonic beam U emitted by the transmission probe 110. As shown in Fig. 2B, the transmission sound axis AX1 includes refraction by the interface of the subject E. That is, as shown in FIG. 2B, when the ultrasonic beam U emitted from the transmission probe 110 is refracted at the interface of the object E to be inspected, the center of the propagation path of the ultrasonic beam U ( sound axis) becomes the transmission sound axis AX1.

In addition, the receiving sound axis AX2 is defined as the negative axis of the propagation path of the virtual ultrasonic beam when it is assumed that the eccentrically placed receiving probe 120 emits the ultrasonic beam U. In other words, the receiving sound axis AX2 is the central axis of the virtual ultrasonic beam when it is assumed that the eccentrically placed receiving probe 120 emits the ultrasonic beam U.

As a specific example, a case of a non-converging type receiving probe having a flat transducer surface will be described. In this case, the direction of the reception sound axis AX2 is the normal direction of the probe surface, and the axis passing through the center point of the probe surface becomes the reception sound axis AX2. When the probe surface is rectangular, the center point is defined as the intersection of diagonal lines of the rectangle.

The reason why the direction of the receiving sound axis AX2 is the normal direction of the transducer surface is that the virtual ultrasonic beam U emitted from the receiving probe 121 is emitted in the normal direction of the transducer surface. Even in the case of receiving the ultrasonic beam U, the ultrasonic beam U incident in the direction normal to the transducer surface can be received with high sensitivity.

The eccentric distance L is defined as the distance between the transmission sound axis AX1 and the reception sound axis AX2. Therefore, as shown in FIG. 2B, when the ultrasonic beam U emitted from the transmission probe 110 is refracted, the eccentricity distance L is the difference between the refracted transmission sound axis AX1 and the reception sound axis AX2. is defined as the distance of In the ultrasonic inspection apparatus Z of the present embodiment, the transmission probe 110 and the eccentric arrangement receiving probe ( 120) is adjusted. As a result, the ultrasonic beam U (FIG. 3) emitted from the transmitting probe 110 and transmitted around the defective portion D (FIG. 1) is reduced, and the defective portion D in the receiving probe 121 is reduced. ) can be easily detected.

However, in the present embodiment, as a preferred example, as described above, the eccentrically disposed receiving probe 120 receives the scattered wave U1 (FIG. 6B) generated by scattering of the ultrasonic beam U at the defect portion D. do. Since the scattered wave U1 is generated by the presence of the defective portion D, the detection accuracy of the defective portion D can be further improved by detecting the scattered wave U1. In the following example, for simplification of description, the present embodiment will be described taking the eccentrically placed receiving probe 120 installed at a position capable of receiving the scattered wave U1 as an example.

FIG. 2A shows a case in which the transmission probe 110 is disposed in the normal direction on the surface of the object E to be inspected. 2A and 2B, the transmission sound axis AX1 is indicated by a solid arrow. Also, the reception sound axis AX2 is indicated by an arrow with a dashed-dotted line. 2A and 2B, the position of the receiving probe 121 indicated by the broken line is the position where the eccentricity distance L is zero, and the receiving probe 121 at which the transmission sound axis AX1 and the reception sound axis AX2 coincide Coaxial batch receiving probe 140. Also, a receiving probe 121 indicated by a solid line is an eccentrically arranged receiving probe 120 disposed at a position having an eccentric distance L greater than zero. When the transmission probe 110 is installed so that the transmission sound axis AX1 is perpendicular to the horizontal plane (xy plane in FIG. 1), the propagation path of the ultrasonic beam U is not refracted. That is, the transmission sound axis AX1 is not refracted.

FIG. 2B is a diagram showing a case where the transmission probe 110 is tilted by an angle α from the normal direction on the surface of the object E to be inspected. In FIG. 2B, as in FIG. 2A, the transmission sound axis AX1 is indicated by a solid line arrow, and the reception sound axis AX2 is indicated by a dashed-dotted arrow. In the case of the example shown in Fig. 2B, as described above, the propagation path of the ultrasonic beam U is refracted at the refraction angle β at the interface between the subject E and the fluid F. Therefore, the transmission sound axis AX1 is bent (refracted) as indicated by the solid line arrow in FIG. 2B. In this case, since the position of the coaxially placed receiving probe 140 indicated by the broken line is on the transmission sound axis AX1, the eccentric distance L is the position of zero. And, as described above, even when the ultrasonic beam U is refracted, the eccentrically arranged receiving probe 120 is arranged so that the distance between the transmission sound axis AX1 and the reception sound axis AX2 is L. In addition, in the example shown in FIG. 1, since the transmission probe 110 is installed in the normal direction in the surface of the subject E, the eccentric distance L becomes as shown in FIG. 2A.

The eccentricity distance L is set at a position where the signal intensity in the defective portion D is greater than that of the received signal in the intact portion N of the subject E. I will comment on this point.

FIG. 3 is a cross-sectional schematic diagram showing the structure of the transmission probe 110. As shown in FIG. In FIG. 3, for simplification, only the outline of the emitted ultrasonic beam U is shown, but in reality, a plurality of ultrasonic beams ( U) is released.

The transmitting probe 110 is configured to converge the ultrasound beam U. Thereby, the minute defect part D in the subject E can be detected with high precision. The reason why the minute defect portion D can be detected will be described later. The transmission probe 110 includes a transmission probe housing 115 , and includes a backing 112 , a vibrator 111 , and a matching layer 113 inside the transmission probe housing 115 . An electrode (not shown) is attached to the vibrator 111, and the electrode is connected to the connector 116 by a lead wire 118. In addition, the connector 116 is connected to the power supply unit (not shown) and the control unit 2 via lead wires 117 .

In this specification, the transducer surface 114 of the transmission probe 110 or the reception probe 121 is defined as the surface of the matching layer 113 when the matching layer 113 is provided, and the matching layer 113 If not provided, it is defined as the surface of the vibrator 111. That is, the transducer surface 114 is a surface that emits the ultrasonic beam U in the case of the transmission probe 110, and a surface that receives the ultrasonic beam U in the case of the reception probe 121.

FIG. 4A is a received waveform from the eccentrically placed receiving probe 120, and is a diagram showing the received waveform at the healthy part N of the object E to be inspected. FIG. 4B is a received waveform from the eccentrically placed receiving probe 120, and is a diagram showing the received waveform at the defective portion D of the object E to be inspected. 4B shows a received signal when the transmission probe 110 is placed at the xy coordinate position of a cavity (defect portion D) with a width of 2 mm provided in the subject E to be inspected. 4A and 4B, the time represents the elapsed time after the burst wave is applied to the transmission probe 110, and a stainless steel plate having a thickness of 2 mm was used as the subject E to be inspected. A burst wave with a frequency of 800 KHz was applied to the transmission probe 110 . More specifically, a burst wave composed of 10 sine waves was applied to the subject E at regular intervals.

In FIG. 4A, no significant signal is observed, but in FIG. 4B, a significant signal is observed 90 microseconds after the burst wave is applied to the transmission probe 110. The delay of 90 microseconds until this significant signal is observed is because it takes time from the emission of the ultrasonic beam U to the arrival of the scattered wave U1 to the eccentrically arranged receiving probe 120. Specifically, while the sound speed in the air is 340 (m/s), in stainless steel constituting the subject E, it is about 6000 (m/s), so a delay of 90 microseconds occurs.

5 is a diagram showing an example of a plot of signal strength data. In this example, the transmitting probe 110 and the eccentrically placed receiving probe 120 are scanned in the x-axis direction for the defect portion D having a width of 2 mm, and the received signal at the x-axis position (received signal shown in FIG. 4B) ), the extracted signal intensity data (signal amplitude for each scanning position) is plotted. In this embodiment, signal strength data is extracted by extracting the Peak To Peak value of the received signal shown in FIG. 4B, that is, the difference between the maximum value and minimum value in an appropriate time domain. As another example of a method for extracting signal strength data, the received signal shown in FIG. 4B may be converted into frequency components by signal processing such as short-time Fourier transform, and the strength of an appropriate frequency component may be extracted. Further, as the signal intensity data, a correlation function may be calculated using an appropriate reference wave as a standard. In this way, signal strength data is obtained corresponding to each scan position of the transmission probe 110 .

In the plot of signal strength data shown in FIG. 5, a 2 mm wide cavity (defective portion D) corresponds to the symbol D1 in FIG. While the sound level N of the inspected object E (the part other than the code D1) is a signal of the noise level, at the position where the defective part D is inside (the code D1), the received signal becomes significantly larger. it can be seen that there is

Therefore, the eccentric distance adjustment unit 105 adjusts the eccentricity distance L so that the received signal intensity from the eccentrically arranged receiving probe 120 when incident on the defective part D is greater than the received signal strength when incident on the sound part N. It is desirable to adjust By doing this, it is possible to detect the defective portion D based on the received signal strength. This eccentric distance L is, for example, the reception sound axis AX2 of the eccentrically arranged receiving probe 120 and the transmission sound axis AX1 of the transmission probe 110 arranged at a position capable of receiving the scattered wave U1 (FIG. 6B). is the distance from The eccentricity distance adjusting part 105 is comprised by an actuator, a motor, etc., although all are not shown, for example.

In addition, the eccentricity distance adjustment unit 105 preferably adjusts the eccentricity distance L to a distance at which received signals other than noise are not detected during irradiation to the sound portion N. That is, it is preferable that the eccentric distance adjusting unit 105 sets the eccentric distance L so that a significant received signal does not come out from the sound part N of the inspected object E. By doing this, the SN ratio can be increased, and the defective portion D can be determined at a location where a received signal other than noise is detected, and the defective portion D can be detected.

The eccentricity distance L can be determined using, for example, a standard sample made of the same material as the inspected object E and having a defective portion D therein. In addition, the eccentricity distance L may be determined based on a position where an ultrasonic beam U may be irradiated onto the defective portion D of the standard sample and the ultrasonic beam U or the scattered wave U1 may be received.

When the transmission probe 110 is scanned in one dimension only in the x-axis direction, the graph of signal strength data shown in FIG. 5 is displayed on the display device 3 . In the case where the scanning direction of the transmission probe 110 is two-dimensional in the x-axis direction and the y-axis direction, by plotting the signal strength data, the position of the defect portion D is represented as a two-dimensional image, which is displayed on the display device ( 3) is displayed.

FIG. 6A is a diagram showing the propagation path of the ultrasonic beam U in the present embodiment, when the ultrasonic beam U is incident on the sound portion N. Fig. 6B is a diagram showing the propagation path of the ultrasonic beam U in the present embodiment, and showing the case where the ultrasonic beam U is incident on the defect portion D.

As shown in FIGS. 6A and 6B , the ultrasonic beam U emitted from the transmission probe 110 is incident on the object E to be inspected. As shown in FIG. 6A, when the ultrasonic beam U is incident on the sound portion N, the ultrasonic beam U passes so as to converge toward the transmission sound axis AX1. For this reason, the received signal is not observed in the eccentrically arranged receiving probe 120 which is arranged while maintaining the eccentric distance L. On the other hand, as shown in FIG. 6B, when the ultrasonic beam U is incident on the defective part D, the ultrasonic beam U is scattered in the defective part D, and the scattered wave U1 is installed eccentrically. It is received by the eccentric arrangement receiving probe 120 . Therefore, a significant received signal is observed.

In this way, the scattered wave U1 scattered by the defective portion D in the inspected object E is observed by the eccentrically arranged receiving probe 120 . Therefore, the received signal in the defective part D is larger than the received signal in the sound part N. That is, it is determined that the defective portion D is present at a position where the signal is high. Therefore, the eccentric distance adjusting unit 105 sets the eccentric distance L to a distance capable of receiving the scattered wave U1 generated by scattering of the irradiated ultrasonic beam U at the defective portion D of the object E to be inspected. It is desirable to adjust By doing so, the scattered wave U1 peculiar to the defective portion D can be detected, and the detection accuracy of the defective portion D can be improved.

The eccentric distance L is preferably such that only the scattered wave U1 can be selectively received without receiving the ultrasonic beam U emitted from the transmission probe 110 . Thereby, the SN ratio can be increased, and the detection performance of the defect portion D, in particular, the detection sensitivity can be improved. Here, "detection sensitivity is high" means that a smaller defect part D can be detected than the conventional method. That is, the lower limit of the size of the detectable defect portion D is smaller than that of the conventional method.

Here, as a comparative example, a conventional ultrasonic inspection method will be described.

Fig. 7A is a diagram showing a propagation path of an ultrasonic beam U in a conventional ultrasonic inspection method, and is a diagram showing the incidence of an ultrasonic beam U into a sound portion N. FIG. 7B is a diagram showing a propagation path of an ultrasonic beam U in a conventional ultrasonic inspection method, and is a diagram showing the incidence of an ultrasonic beam U on a defect D. FIG. In a conventional ultrasonic inspection method, as described in Patent Literature 1, for example, the transmission probe 110 and the reception probe 121 are coaxially arranged and received so that the transmission sound axis AX1 and the reception sound axis AX2 coincide. A probe 140 is placed.

As shown in FIG. 7A, when the ultrasonic beam U is incident on the healthy part N of the object E to be inspected, the ultrasonic beam U passes through the object E to be inspected, and the coaxial arrangement receiving probe 140 ) is reached. Therefore, the received signal becomes large. On the other hand, as shown in FIG. 7B, when the ultrasonic beam U is incident on the defective portion D, transmission of the ultrasonic beam U is blocked by the defective portion D, so that the received signal decreases. In this way, the defective part D is detected by the reduction of the received signal. This is as disclosed in Patent Literature 1.

Here, as shown in FIGS. 7A and 7B, transmission of the ultrasonic beam U in the defective portion D is prevented so that the received signal is reduced and a method of detecting the defective portion D is described as " It will be referred to as "the Law of Deterrence". On the other hand, as in the present embodiment, the inspection method for detecting the scattered wave U1 in the defect portion D will be referred to as a "scattering method".

8 is a diagram showing a plot of signal strength data in a conventional ultrasonic inspection method. This figure shows the inventors' ultrasonic inspection method according to the method shown in FIGS. 7A and 7B, that is, an arrangement in which the transmission sound axis AX1 and the reception sound axis AX2 are aligned, and the test subject used in FIG. 5 above. It is a signal intensity graph obtained by examining an object E having a defect D same as that of a corpse E. In Fig. 8, the part indicated by the symbol D1 corresponds to the defective part D.

In Fig. 8, a decrease in the signal is confirmed at the center position of the defective portion D (position is 0 mm), but the amount of decrease is small. This is considered to be due to the fact that, in the defect portion D that is smaller than the size of the ultrasonic beam U, the ultrasonic beam U transmitted through its periphery is large. For this reason, in the blocking method in which the transmission sound axis AX1 and the reception sound axis AX2 are matched, it is difficult to detect a signal change originating from the defective portion D, and the detection sensitivity is low.

On the other hand, by shifting the transmission sound axis AX1 and the reception sound axis AX2, transmission around the defective part D smaller than the size of the ultrasonic beam U is transmitted among the signal strengths received by the eccentric arrangement receiving probe 120. It is possible to reduce the signal of the ultrasonic beam U to be used. This makes it possible to increase the amount of decrease in the signal intensity due to the defective portion D, and to improve the detection performance of the defective portion D, particularly the detection sensitivity. Among them, as shown in FIG. 5 above, according to the configuration by the scattering method suitable for this embodiment, compared with the result of FIG. 8 by the blocking method, the position of the defective portion D can be clearly detected. know what can be That is, when comparing the reception result shown in FIG. 8, which is a comparative example, with the reception result of the method according to the present embodiment shown in FIG. 5, the method according to the present embodiment shown in FIG. 5 obtains a higher SN ratio. lose

In this way, the reason why the scattering method of the present embodiment can obtain a high SN ratio will be described with reference to FIGS. 9A and 9B.

Fig. 9A is a diagram showing the interaction of the ultrasonic beam U with the defect portion D in the inspected object E, and the direct ultrasonic beam U (hereinafter referred to as "direct wave U3"). It is a drawing showing how to receive a speech). The direct wave (U3) will be described later. FIG. 9B is a diagram showing the interaction between the defect portion D and the ultrasonic beam U in the object E to be inspected, and is a diagram showing how the scattered wave U1 is received. Here, the case where the size of the defective portion D is smaller than the width of the ultrasonic beam U (hereinafter referred to as the beam width BW) will be considered. The beam width BW here is the width of the ultrasonic beam U when it reaches the defective portion D.

9A and 9B schematically show the shape of the ultrasonic beam U in a small area near the defect portion D, so the ultrasonic beam U is shown in parallel, but actually converged. It is an ultrasonic beam (U). In addition, the position of the receiving probe 121 in FIGS. 9A and 9B is a conceptual position written for easy understanding, and the position and shape of the receiving probe 121 are not accurately scaled. That is, considering the magnified scale of the shape of the defect part D and the ultrasonic beam U, the receiving probe 121 is located at a position spaced apart in the vertical direction in the drawing from the positions shown in Figs. 9A and 9B. Here, the receiving probe 121 is the coaxially disposed receiving probe 140 in FIG. 9A and the eccentrically disposed receiving probe 120 in FIG. 9B.

The ultrasonic beam U has a certain finite width in the vicinity of the defect portion D even when it is incident upon convergence. Let this be the beam width BW at the position of the defect part D. Incidentally, in FIGS. 9A and 9B , the case where the beam width BW at the position of the defective portion D is wider than the size of the defective portion D is shown.

Fig. 9A is a diagram showing a case of a blocking method in which the transmitted sound axis AX1 and the received sound axis AX2 are matched. When the defect portion D is smaller than the beam width BW, part of the ultrasonic beam U is blocked, so the received signal decreases, but does not become zero. For example, when the cross-sectional area of the defective portion D is 20% of the cross-sectional area of the beam defined by the beam width BW, the received signal is only reduced by approximately 20%, making it difficult to detect the defective portion D. That is, in the case shown in Fig. 9A, the received signal only decreases by 20% at the location where the defective part D exists (see Fig. 8).

9B is a diagram showing a case of a suitable method of the present embodiment, that is, a case of the scattering method. In the scattering method, when the ultrasonic beam U does not reach the defective portion D, the ultrasonic beam U is not incident on the eccentrically arranged receiving probe 120, so the received signal is zero. And, as shown in FIG. 9B, even when a part of the ultrasonic beam U touches the defective portion D, since the scattered wave U1 is observed by the eccentrically arranged receiving probe 120, the defective portion is compared to the blocking method. Detection of part (D) is easy. That is, if the defective portion D does not exist, the received signal becomes zero, and even if it is small, if the defective portion D exists, the received signal becomes non-zero. Therefore, it becomes possible to increase the SN ratio (see Fig. 5).

In this way, according to the method (scattering method) according to the present embodiment, a defect portion D smaller than the beam width BW can be detected with high sensitivity. Here, "can be detected with high sensitivity" means that a smaller defect portion D can be detected than in the conventional method. That is, the lower limit of the size of the detectable defect portion D is smaller than that of the conventional method.

Further, as shown in Fig. 9A, in the blocking method, the defective portion D is determined based on the received signal amount corresponding to the sound portion N, and the amount of decrease therefrom. Therefore, it is desirable that the received signal in the sound section N be a constant value. However, the intensity of ultrasonic waves propagating through the liquid F, especially gas G, reaching the receiving probe 121 is very small compared to ultrasonic waves propagating through the liquid W (FIG. 17). Therefore, it is desirable to amplify the received signal with a high amplification factor (gain). For this reason, in order to keep the gain constant, a highly accurate signal amplifier circuit is desirable. On the other hand, in the scattering method according to the present embodiment, as shown in Fig. 5, since the signal is almost zero in the sound portion N and the signal is observed in the defective portion D, the gain stability of the signal amplifying circuit is affected. needs can be reduced. However, in the above FIG. 5, the signal intensity value is leveled up by the offset value.

Also, in this embodiment, a positive image is obtained. That is, in the scattering method, no signal is generated in the healthy part (N) or small even if it is generated, and a new signal is generated or the signal is increased in the defective part (D). That is, a positive image of the defective portion D is obtained. On the other hand, in the blocking method, the signal is large in the sound part (N) and the signal is decreased in the defective part (D). That is, a negative image of the defective portion D is obtained.

10 is a functional block diagram of the control device 2. The control device 2 includes a transmission system 210, a reception system 220, a data processing unit 201, a scan controller 204, a drive unit 202, and a position measurement unit 203.

The transmission system 210 is a system that generates a voltage applied to the transmission probe 110 . The transmission system 210 includes a waveform generator 211 and a signal amplifier 212. A burst wave signal is generated in the waveform generator 211. Then, the generated burst wave signal is amplified by the signal amplifier 212. A voltage output from the signal amplifier 212 is applied to the transmission probe 110 .

The receiving system 220 is a system that detects a received signal output from the eccentrically arranged receiving probe 120 . A signal output from the eccentric arrangement receiving probe 120 is input to a signal amplifier 222 and amplified. The amplified signal is input to the waveform analysis unit 221 . The waveform analyzer 221 generates signal strength data (FIG. 5) from the received signal. The generated signal strength data is sent to the data processing unit 201.

The receiving system 220 includes a phase extractor 231. The output signal of the signal amplifier 222 is input to the phase extractor 231 . The phase extractor 231 extracts phase information of the signal of the ultrasonic beam U (scattered wave U1) received by the eccentrically placed receiving probe 120 . The extracted phase information is sent to the phase change calculation unit 232 of the data processing unit 201 .

The phase of the signal is a delay time from when the ultrasonic beam U is emitted from the transmission probe 110 to reaching a specific position of the received signal. The specific position of the received signal indicates the position of the characteristic received signal from which the delay time can be easily calculated among the received signals. For example, when a burst wave of 10 waves is used, this is the position of the third wave.

Further, as the phase of the signal, a delay time within the basic period of the signal may be used. The fundamental period of a signal is the reciprocal of the fundamental frequency f0. For example, when a burst wave with a fundamental frequency f0 = 800 kHz is used, the basic period is 1.25 μs. The phase extractor 231 calculates a specific position of the received signal, for example, where the zero cross point is located during the basic period. In this embodiment, the phase extractor 231 calculates the phase within the basic period by calculating a remainder obtained by dividing the delay time by the basic period T0 of the signal.

The data processing unit 201 includes a phase change amount calculating unit 232 . The phase change calculation unit 232 receives the phase information as an input signal, and also receives scan position information from the scan controller 204 . Using these two pieces of information, the phase change amount calculation unit 232 calculates the phase change amount (phase change amount for each scanning position) of the phase information extracted by the phase extractor 231 with respect to the scanning position. This amount of change corresponds to the amount of spatial differential with respect to the scanning position of the phase information of the signal.

In addition to the change amount (spatial differential amount), the "phase change amount related to the scanning position" includes a signal amount (change amount) representing a change in magnitude of the change amount (spatial differential amount), such as its square value or absolute value. By scanning on the xy two-dimensional plane and calculating the amount of change with respect to this two-dimensional scanning position (x, y), an image in which the outline of the defective portion D can be easily grasped is obtained.

The method for calculating the amount of change in phase information in the phase change amount calculation unit 232 is, for example, arithmetic processing by a CPU (central processing unit) or microcomputer (microcontroller), field-programmable gate array (FPGA), or the like. It includes digital signal processing of, signal processing by analog circuit, and the like.

In this way, at each scan position in the x-axis direction and the y-axis direction, by the phase extractor 231 and the phase change amount calculator 232, the phase change of the signal is extracted and the phase change amount related to the scan position is calculated Signal changes due to differences in scanning positions will be described below.

Fig. 11 is a diagram schematically showing changes in the received signal of the eccentrically placed receiving probe 120 at each scan position in the x-axis direction. The broken line in the vertical direction is the existence position of the defect part D, and the width of the defect part D is WD. For reference, a graph G1 shows the signal amplitude when the coaxial arrangement receiving probe 140 based on the transmission method is installed. Graph G2 shows the signal amplitude of the signal received by the eccentrically placed receiving probe 120, and is an output signal of the waveform analysis section 221. In any of the graphs G1 and G2, the signal amplitude is large in the vicinity of the defective portion D, and it is understood that the defective portion D can be detected.

However, in any of the graphs G1 and G2, the width of the signal is wider than WD, which is the size (width) of the defective portion D. The reason for this is that the beam size of the ultrasonic beam U is large. That is, since a scattered wave U1 is generated even when a part of the ultrasonic beam U is irradiated to the defective portion D, the signal amplitude of the scattered wave U1 gradually increases in the vicinity of the defective portion D. For this reason, the signal amplitude is larger than the actual size of the defective portion D. This corresponds to a state in which, when displayed on the display device 3, the size of the defective portion D is apparently larger than the actual size and the resolution is lowered. Therefore, based only on the graphs G1 and G2, the resolution of the image displayed on the display device 3 and showing the outline of the defective portion D may be lowered.

A graph G3 is a plot of the signal phase of the scattered wave U1, and is an output signal of the phase extractor 231 (FIG. 10). It can be seen that the phase signal of the scattered wave U1 (Fig. 6B) changes rapidly at the position of the defect portion D (Fig. 6B). The reason for this will be described later with reference to FIGS. 12A to 12C. A graph G4 plots the amount of phase change with respect to the scanning position in the x-axis direction of the phase signal of the scattered wave U1, and is an output signal of the amount of phase change calculator 232 (FIG. 10). A graph G4 corresponds to a signal obtained by spatially differentiating the phase signal of the scattered wave U1 with respect to the scanning position in the x-axis direction. In addition, the graph G5 is a plot obtained by squaring the values of the graph G4. Based on the graphs G4 and G5, it can be seen that a signal corresponding to the outline of the defective portion D, that is, a high-resolution image representing the outline of the defective portion D is obtained. Therefore, it can be seen that the defective part D can be detected with high resolution by calculating the amount of phase change with respect to the signal phase scanning position of the scattered wave U1 by comparing the graph G2 with the graphs G3 to G5. there is.

FIG. 12A is a diagram showing a scanning position at which the ultrasonic beam U is not incident on the defective portion D. Fig. 12B is a diagram showing a scanning position where the ultrasonic beam U is incident on the defective portion D but the transmission sound axis AX1 does not enter the defective portion D. Fig. 12C is a diagram showing scanning positions where the ultrasonic beam U is incident on the defective portion D and the transmission sound axis AX1 enters the defective portion D. The reason why the phase of the scattered wave U1 changes rapidly at the position of the defective portion D is estimated according to the present inventor's examination for the following reasons.

When scanning at the scanning position x1 where the ultrasonic beam U is not incident on the defective portion D (FIG. 12A), no scattered wave U1 is generated, as shown in the graphs G1 and G2 of FIG. 11. One signal amplitude does not change. However, when scanning at a scanning position x2 where the ultrasonic beam U is incident on the defective portion D but the transmission sound axis AX1 does not enter the defective portion D (FIG. 12B), the defective portion D A scattered wave U1 is generated even when a part of the ultrasonic beam U is incident. For this reason, as shown in the graphs G1 and G2 of Fig. 11 above, a change in signal amplitude is observed. However, as shown in the graphs G3 to G5 of FIG. 11, the phase does not change. This is considered to be because the eccentrically placed receiving probe 120 receives receiving components including the scattered wave U1 and the ultrasonic beam U from various directions, and as a result of mixing them, it becomes difficult to confirm a change in phase. .

As shown in FIG. 12C, at the scanning position x3 where the ultrasonic beam U enters the defective portion D and the transmission sound axis AX1 enters the defective portion D, the graph of FIG. 11 As shown in (G3 to G5), the phase changes remarkably. This is because the transmission sound axis AX1 of the ultrasonic beam U enters the defective portion D, so that the ultrasonic beam U enters the defective portion D in a state suitable for scattering in the defective portion D. It is thought that It is considered that this is because the eccentrically placed receiving probe 120 receives the receiving component, most of which is the scattered wave U1, and a significant phase change occurs.

In this way, when the transmission sound axis AX1 of the ultrasonic beam U is irradiated to the defective portion D, that is, when most of the received components in the eccentrically arranged receiving probe 120 are the scattered waves U1, the scattered waves The phase change of (U1) can be clearly grasped. Therefore, based on the phase change of the scattered wave U1, the position of the defective portion D can be ascertained.

Returning to FIG. 10 , the data processing unit 201 images the information about the defective portion D of the inspected object E, detects the presence or absence of the defective portion D, and the like, and converts the acquired information to process in the desired form. In addition, images and information generated by the data processing unit 201 are displayed on the display device 3 .

The scan controller 204 drives and controls the transmission probe scanning unit 103 and the reception probe 104 shown in FIG. 1 . Drive control of the transmission probe scanning unit 103 and the receiving probe 104 is performed through the driving unit 202 . In addition, the scan controller 204 measures positional information (each scanning position in the x-axis direction and the y-axis direction, xy coordinates) of the transmission probe 110 and the eccentric arrangement receiving probe 120 through the position measurement unit 203. do.

The data processing unit 201 plots, images, and displays signal intensity data at each position based on the position information of the transmission probe 110 and the eccentric arrangement reception probe 120 received from the scan controller 204. displayed on the device (3). As described above, the signal strength data acquired in the defective part D is greater than the signal strength data in the sound part N. Therefore, by plotting the signal strength data with respect to the scanning position of the transmission probe 110, an image indicating where the defective portion D is located can be obtained. The display device 3 displays this image.

The data processing unit 201 generates an image by also plotting the output signal from the phase change calculation unit 232 with respect to the scanning position of the transmission probe 110, and displays it on the display device 3. As will be described later, an output signal from the phase change amount calculation unit 232 gives an image corresponding to the contour image of the defective portion D.

The two images of the image from which the signal strength data is generated and the image output from the phase change amount calculation unit 232 may be superimposed and displayed as one image. The superimposed image is an image displayed by superimposing a second image on a first image. At this time, the first image and the second image are overlapped so that the scanning positions of the two images correspond. For example, the image of the signal intensity data may be displayed as a gray-graded black-and-white image, and the image output from the phase change amount calculator 232 may be superimposed and displayed in a different color such as yellow.

13 is a diagram showing the hardware configuration of the control device 2. As shown in FIG. The control device 2 includes a memory 251 such as random access memory (RAM), a central processing unit (CPU) 252, a read only memory (ROM), a storage device 253 such as a hard disk drive (HDD), It is configured with a communication device 254 such as a NIC (Network Interface Card), an I/F (Interface) 255, and the like.

In the control device 2, a predetermined control program stored in the storage device 253 is loaded into the memory 251 and executed by the CPU 252. As a result, the data processing unit 201, the position measurement unit 203, the scan controller 204, the phase extraction unit 231, the phase change calculation unit 232, and the like of FIG. 3 are implemented.

14 is a flowchart showing the ultrasonic inspection method according to the first embodiment. The ultrasonic inspection method of the first embodiment can be executed by the ultrasonic inspection apparatus Z described above, and will be described appropriately with reference to FIGS. 1 and 10 . In the ultrasonic inspection method of the first embodiment, the inspection subject E is inspected by incident ultrasonic beam U on the inspection subject E (FIG. 1) through the base G (FIG. 1). In addition, this ultrasonic inspection method is described for an embodiment in which gas G is used as the fluid F, but this ultrasonic inspection method also applies to an embodiment in which a liquid W ( FIG. 17 ) is used as the fluid F. Valid, of course.

First, emission step S101 of emitting the ultrasonic beam U (FIG. 6B) from the transmission probe 110 (FIG. 1) is performed by a command of the control device 2 (FIG. 10). Subsequently, reception step S102 of receiving the ultrasonic beam U (scattered wave U1 in this example) in the eccentrically placed receiving probe 120 (FIG. 1) is performed.

Thereafter, a phase extraction step of extracting phase information of a signal based on a signal (eg, a waveform signal) of the ultrasonic beam U (scattered wave U1 in this example) received by the eccentrically placed receiving probe 120. S103 is performed. Phase extraction step S103 is performed by phase extraction unit 231 (FIG. 10), and phase extraction unit 231 extracts (generates) signal phase information from, for example, the received signal shown in FIG. 4B. .

The output signal of the phase extraction unit 231 is input to the phase change amount calculation unit 232 (FIG. 10), and phase change amount calculation step S104 for calculating the phase change amount with respect to the scanning position of the extracted phase information is performed. In the phase change amount calculation step S104, the amount of phase change per unit length change of the scan position is calculated with reference to the scan position information (coordinate position) sent from the scan controller 204 (FIG. 10). The phase change amount calculation step S104 is performed by the phase change amount calculation unit 232 .

Scanning position information of the transmission probe 110 and the eccentric arrangement reception probe 120 is transmitted from the position measuring unit 203 (FIG. 10) to the scan controller 204 (FIG. 10). The data processing unit 201 (FIG. 10) plots the amount of phase change at each scanning position with respect to the scanning position information of the transmission probe 110 obtained from the scan controller 204. In this way, for example, the graphs G3 to G5 shown in Fig. 11 are obtained, and the amount of phase change is visualized.

In addition, in FIG. 11, the scanning position information is one-dimensional (one direction), and for the case where the scanning position information is two-dimensional (x, y), by plotting the amount of phase change, the contour information of the defective part D is 2 It is represented as a dimensional image, and it is displayed on the display device 3.

Following phase change amount calculation step S104, shape display step S105 is performed. The shape display step S105 determines whether or not the amount of phase change with respect to the scanning position of the phase information generated in the amount of phase change calculation step S104 is equal to or greater than a preset threshold, thereby determining the defect portion D of the subject E. The shape is displayed on the display device 3, for example. On the display device 3, for example, an image drawn at a scanning position exceeding a threshold is displayed. In this way, since the effect that the outline of the defective part D can be clearly shown is obtained, it is more preferable. The shape display step S105 is performed by the data processing unit 201.

The data processing unit 201 determines whether scanning has been completed (step S111). If the scan is complete ("Yes"), the control device 2 ends the process. When the scan is not completed (“No”), the data processing unit 201 outputs a command to the driving unit 202 (FIG. 10) to move the transmission probe 110 and the eccentric arrangement reception probe 120 to the next scanning position. It is moved (step S112), and the process returns to release step S101.

According to the above ultrasonic inspection apparatus Z and ultrasonic inspection method, the detection performance of a defect part, for example, the resolution of a display image can be improved, and the position of the defect part D can be grasped easily.

Further, the fluid F may be a gas G (FIG. 1) as described above, or may be a liquid W (FIG. 17) as described later. However, when a gas G such as air is used as the fluid F, more favorable effects are provided for the following reasons.

Compared to that in the liquid (W), the attenuation of ultrasonic waves is greater in the gas (G). It is known that the amount of attenuation of ultrasonic waves in gas (G) is proportional to the square of the frequency. For this reason, in order to propagate ultrasonic waves in the base G, about 1 MHz becomes an upper limit. In the case of the liquid W, since ultrasonic waves of 5 MHz to several tens of MHz propagate, the usable frequency in the gas G is smaller than that in the liquid W.

In general, when the frequency of the ultrasonic wave is lowered, convergence of the ultrasonic beam U becomes difficult. Therefore, the 1 MHz ultrasonic beam that propagates in the gas G has a larger beam diameter that can be bound compared to that of the ultrasonic beam U in the liquid W. For this reason, the amplitude image detected by the coaxial arrangement receiving probe 140 (FIG. 2A) may have a low resolution when the gas G is used as the fluid F.

However, according to the present disclosure, even when the gas G is used as the fluid F, the amount of phase change (spatial differential amount) of the scattered wave U1 detected by the eccentrically placed receiving probe 120 with respect to the scanning position is defective. An image close to the outline of section D is obtained. For this reason, high resolution is obtained not only when the liquid W is used as the fluid F, but also when the gas G is used. In this way, the effect of the present disclosure becomes higher when the gas (G) is used as the fluid (F).

(Second Embodiment)

15 is a diagram schematically showing the configuration of an ultrasonic inspection apparatus Z according to the second embodiment. In the second embodiment, the scan measuring device 1 includes a coaxially positioned receiving probe 140 in addition to the eccentrically placed receiving probe 120 . Here, the coaxially placed receiving probe 140 is the receiving probe 121 disposed at a position where the eccentric distance L becomes zero. That is, the reception sound axis AX2 of the coaxially arranged receiving probe 140 is the same as the transmission sound axis AX1 of the transmission probe 110 .

16 is a diagram showing the configuration of the control device 2 according to the second embodiment. The output signal of the eccentric arrangement receiving probe 120 is input to the receiving system 220a, and phase information is extracted from it by the phase extraction unit 231. The phase information is input to the data processing unit 201, and the phase change amount with respect to the phase scanning position of the signal is calculated by the phase change amount calculation unit 232 therein. This amount of phase change corresponds to the outline of the defective portion D as described above. In the phase change amount calculation unit 232, outline image data is generated.

The output signal of the coaxial arrangement receiving probe 140 is input to the receiving system 220b, and after being amplified by the signal amplifier 223, the waveform analysis unit 221 extracts amplitude information of the signal. Since the reception sound axis AX2 of the coaxially arranged receiving probe 140 is installed so as to coincide with the transmission sound axis AX1 of the transmission probe 110, the transmission amount of the ultrasonic beam U is blocked in the defective portion D. , the amplitude of the received signal of the coaxially placed receiving probe 140 decreases in the defective part D. This is a defect detection method in the prior art "prevent mode". The output signal of the waveform analysis section 221 of the receiving system 220b to which the coaxial batch receiving probe 140 is connected is input to the data processing section 201, and the amplitude image generation section 224 of the signals generates amplitude image data. generate

In the above procedure, contour image data is generated from the signal of the eccentrically placed receiving probe 120, and amplitude image data is generated from the signal from the coaxially placed receiving probe 140. These two image data are input to the image synthesis unit 225 of the data processing unit 201 . The image combining unit 225 combines (overlaps) amplitude image data (first image) and outline image data (second image). As described above, the amplitude image data is the object under test E, which is generated by the amplitude image generation unit 224 based on the amplitude of the direct wave U3 (FIG. 9A) received by the coaxial arrangement receiving probe 140. It represents the position of the defect part D inside the . The outline image data represents the outline of the defect portion D inside the inspected object E, generated by the phase change calculation unit 232 based on the phase change amount related to the scanning position. The synthesized image is input to the display device 3 and displayed.

When observing a defect portion D smaller than the convergence size of the ultrasonic beam U, the amplitude image data becomes an image with a blurred outline, but the outline image data gives a sharp shape closer to the actual size of the defect portion D. do. For this reason, according to the second embodiment, there is an effect that the defective portion D can be imaged with higher resolution.

Further, in the second embodiment, the information (contour image data) from the phase change calculation unit 232 obtained from the signal received by the eccentrically placed receiving probe 120 and the signal received by the coaxially placed receiving probe 140 The obtained information (amplitude image data) from the amplitude image generation unit 224 was synthesized, and superimposed display was performed on the display device 3. However, in the present disclosure, the method of utilizing these two pieces of information, that is, the amount of phase change and the amount of amplitude, is not limited to combining two images.

Another embodiment of the method of utilizing these two pieces of information will be described below. In the following embodiment, by appropriately combining the amount of phase change obtained from the signal received by the eccentrically placed receiving probe 120 and the amplitude obtained from the signal received by the coaxially placed receiving probe 140, the defect part D having high resolution ) can be created and displayed.

As a first example of the method of combining these two signals, the output of the waveform analysis unit 221 from the coaxial arrangement receiving probe 140 at a scanning position where the output signal of the phase change calculation unit 232 exceeds a predetermined threshold value. When the amount of change in the signal, that is, the amplitude signal, exceeds a predetermined threshold, it can be determined that there is a defect portion D at the scanning position. The information of the defective portion D determined in this way is displayed on the display device 3 as an image of the defective portion D together with the scanning position information. Accordingly, in calculating the amount of phase change, which is the amount of spatial change of the phase change, even when a signal change occurs due to unintentional noise mixing or the like, it is possible to suppress the occurrence of false detection of the defective portion D.

In the second example, the output signal of the phase change calculation unit 232 is used as the contour information of the defect part D, and the amplitude value of the received signal of the coaxially placed receiving probe 140 is used, and the contour is delimited. It is possible to determine which region of the image corresponds to the position of the defective portion D. Based on the determination, a defective image is displayed on the display device 3 . In this way, the defective portion D can be displayed with good resolution.

(Third Embodiment)

17 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a third embodiment. In the third embodiment, the fluid F is a liquid W, and in the illustrated example, it is water. The ultrasonic inspection apparatus Z inspects the subject E by making the ultrasonic beam U incident on the subject E through the liquid W as the fluid F. The inspected object E is disposed below the liquid level L0 of the liquid W, and is immersed in the liquid W. The ultrasonic inspection device Z includes a scanning measurement device 1 , a control device 2 , and a display device 3 . The display device 3 is connected to the control device 2 .

The scanning measuring device 1 scans and measures an ultrasonic beam U on an object E to be inspected, and has a sample table 102 fixed to a housing 101, and the sample table 102 has a sample table 102 fixed to a housing 101. (E) is loaded. The inspected object E is made of an arbitrary material. The subject E to be inspected is, for example, a solid material, and more concretely, for example, a metal, glass, or resin material. In addition, the inspection subject E has a defect part D inside. The defective portion D is a cavity or the like. An example of the defective part D is a cavity, a foreign material different from the original material, and the like. In the inspected object E, parts other than the defective part D are referred to as a sound part N.

Since the defective portion D and the intact portion N are made of different materials, the acoustic impedance is different between them, and the propagation characteristics of the ultrasonic beam change. In the ultrasonic inspection apparatus Z, this change is observed and the defective part D is detected.

The scanning measuring device 1 includes a transmitting probe 110 that emits an ultrasonic beam U and an eccentrically disposed receiving probe 120 . The transmission probe 110 is installed in the housing 101 through the transmission probe scanning unit 103 and emits an ultrasonic beam U. The eccentric arrangement receiving probe 120 is a receiving probe 121 installed on the opposite side of the transmission probe 110 with respect to the object under test E to receive the ultrasonic beam U. The eccentric arrangement receiving probe 120 has a receiving sound axis AX2 at a position different from the transmission sound axis AX1 of the transmission probe 110 . The distance between the transmission sound axis AX1 and the reception sound axis AX2 is the eccentric distance L. The eccentric arrangement receiving probe 120 is installed in the housing 101 through the receiving probe injection unit 104 .

In addition, even in the case of using a liquid W such as water as the fluid F, among the receiving probes 121 (FIG. 18) that receive ultrasonic waves, the eccentric distance L disposed at a position of zero or more is an eccentrically arranged receiving probe. (120), and the one with the eccentric distance L at the zero position is defined as the coaxially placed receiving probe 140 (FIG. 18). In other words, the receiving probe 121 is a term encompassing the eccentrically disposed receiving probe 120 and the coaxially disposed receiving probe 140 .

In the third embodiment, although the eccentric arrangement receiving probe 120 is displaced by the eccentric distance L in the x-axis direction of FIG. 17 with respect to the transmission probe 110, the eccentric arrangement A receiving probe 120 may be disposed. Alternatively, the eccentrically arranged receiving probe 120 is disposed at L1 in the x-axis direction and L2 in the y-axis direction (ie, when the position of the transmitting probe 110 in the xy plane is used as the origin, the position of (L1, L2)) It can be.

In the third embodiment, as a preferred example, the eccentrically placed receiving probe 120 receives the scattered wave U1 (FIG. 6B) generated by scattering of the ultrasonic beam U at the defect portion D. Since the scattered wave U1 is generated by the presence of the defective portion D, the detection accuracy of the defective portion D can be further improved by detecting the scattered wave U1. In the following example, for simplification of description, the present embodiment will be described taking the eccentrically placed receiving probe 120 installed at a position capable of receiving the scattered wave U1 as an example.

The eccentricity distance L is set at a position where the signal intensity in the defective portion D is greater than that of the received signal in the intact portion N of the subject E. About this point, it is the same as that of 1st Embodiment.

The control device 2 provided in the ultrasonic inspection apparatus Z according to the third embodiment will be described with further reference to FIG. 10 described above. Also in the third embodiment, the control device 2 includes a transmission system 210, a reception system 220, a data processing unit 201, a scan controller 204, a drive unit 202, a position measuring unit ( 203) is provided. The configuration and operation of the control device 2 are the same as in the first embodiment.

The receiving system 220 includes a phase extractor 231. The output signal of the signal amplifier 222 is input to the phase extractor 231 . The phase extractor 231 generates the above phase information from the received signal. The generated phase information is sent to the data processing unit 201.

The data processing unit 201 includes a phase change amount calculating unit 232 . The phase change calculation unit 232 receives the phase information as an input signal, and also receives scan position information from the scan controller 204 . Using these two pieces of information, the phase change amount calculation unit 232 calculates the phase change amount due to the change in the scanning position.

As in the first embodiment, the amount of phase change due to the change in the scanning position corresponds to the contour information of the defective portion D. Therefore, by imaging this amount of phase change corresponding to the scanning position, it is possible to obtain an image of the defect portion with high resolution.

(Fourth Embodiment)

18 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a fourth embodiment. In the fourth embodiment, the scanning measurement device 1 includes a coaxially placed receiving probe 140 in addition to the eccentrically placed receiving probe 120 . Here, the coaxially placed receiving probe 140 is the receiving probe 121 disposed at a position where the eccentric distance L becomes zero. That is, the reception sound axis AX2 of the coaxially arranged receiving probe 140 is the same as the transmission sound axis AX1 of the transmission probe 110 .

In the fourth embodiment, the fluid F is a liquid W, and the liquid W is water, for example. The ultrasonic inspection apparatus Z of the fourth embodiment is controlled by the control apparatus 2 shown in FIG. 16 , for example.

Also in the fourth embodiment, as in the second embodiment, the amplitude image data (first image) based on the signal received by the coaxially placed receiving probe 140 is the signal received by the eccentrically placed receiving probe 120. Contour image data (second image) based on the amount of phase change with respect to the change in the scanning position is synthesized. Synthesis is performed by the image synthesis unit 225 (FIG. 16). Thereby, the defect part D can be detected with high resolution.

(Fifth Embodiment)

Fig. 19 is a diagram showing the configuration of an ultrasonic inspection apparatus Z in the fifth embodiment. In the fifth embodiment, a transmission/reception probe 119 is provided instead of the transmission probe 110 of the ultrasonic inspection apparatus Z (FIG. 17) of the third embodiment. The transmission/reception probe 119 takes charge of the function of the coaxial arrangement reception probe 140 (Fig. 18) in the fourth embodiment and the function of the transmission probe 110 (Fig. 17) in the third embodiment. Accordingly, the transceiver probe 119 emits the ultrasonic beam U and receives the reflected wave from the inspected object E (including the defective portion D).

Fig. 20 is a functional block diagram of the ultrasonic inspection device Z in the fifth embodiment. The transmission/reception probe 119 emits an ultrasonic beam U when an excitation pulse output from the transmission system 210 of the control device 2 is applied. After that, the connection destination of the transmission/reception probe 119 is immediately switched to the reception system 220b of the control device 2. Switching is typically performed using a switch 235 in the control device 2 . In the fifth embodiment, the switch 235 is a relay element or a semiconductor analog switch, for example.

The ultrasonic beam U (reflected wave) reflected in the defect part D is detected by the transmission/reception probe 119. In the transmission/reception probe 119, the sound wave of the reflected wave is converted into an electrical signal and is input to the reception system 220b via the switch 235. In the waveform analysis section 221 in the receiving system 220b, the amplitude information of the reflected wave signal is extracted, and the amplitude image generation section 224 based on the amplitude of the direct wave received by the transmission/reception probe 119, the amplitude image data ( 1st image) is created.

On the other hand, the signal detected by the eccentrically placed receiving probe 120 is input to the receiving system 220a, and the phase information of the signal is extracted in the phase extraction unit 231. By calculating the amount of phase change with respect to the scanning position of this phase information, the amount of phase change calculator 232 generates outline image data (second image). The image synthesis unit 225 synthesizes and superimposes the amplitude image data and the contour image data, and outputs them to the display device 3. In this way, in the display device 3, the two synthesized images are overlapped and displayed.

As described above, the shape of the defect portion D can be detected with higher resolution based on the amount of phase change with respect to the phase scanning position of the scattered wave signal. For this reason, the defect part D can be imaged with higher resolution. In addition, since the transmission/reception probe 119 combines the functions of the transmission probe 110 (FIG. 17) and the coaxial arrangement reception probe 140 (FIG. 18), the configuration of the scanning measuring device 1 can be simplified.

In addition, the ultrasonic inspection apparatus Z according to the fifth embodiment can be realized only by shifting the position of the coaxially placed receiving probe 140 of the conventional ultrasonic inspection apparatus of the obstruction method by the eccentric distance L. That is, the ultrasonic inspection apparatus that has been used so far can be used, and the installation cost can be reduced.

(Sixth Embodiment)

Fig. 21 is a diagram showing the relationship between the transmitting probe 110 and the eccentrically disposed receiving probe 120 in the ultrasonic inspection apparatus Z according to the sixth embodiment. In the sixth embodiment, the relationship between the convergence of the transmitting probe 110 and the eccentrically arranged receiving probe 120 will be described.

In the sixth embodiment, the convergence of the eccentrically placed receiving probe 120 is made gentler than the convergence of the transmitting probe 110. The propagation path of the scattered wave U1 changes somewhat depending on the depth of the defect portion D in the inspected object E, the shape of the defect portion D, and the inclination. Therefore, in the second embodiment, the convergence of the eccentrically placed receiving probe 120 can be made gentle so that the eccentrically placed receiving probe 120 can detect the scattered wave U1 even if the path of the scattered wave U1 changes.

The magnitude relation of the convergence is defined as the magnitude relation of the beam incident areas T1 and T2 on the surface of the inspected object E. The beam incident areas T1 and T2 will be described.

FIG. 22 is a diagram explaining the relationship between the beam incident area T1 of the transmitting probe 110 and the beam incident area T2 of the eccentrically placed receiving probe 120 . The beam incident area T1 of the transmission probe 110 is an intersection area of the ultrasonic beam U emitted from the transmission probe 110 on the surface of the object E to be inspected. In addition, the beam incident area T2 of the eccentrically placed receiving probe 120 is a virtual ultrasonic beam U2 and the surface of the test object E assuming the case where the ultrasonic beam U is emitted from the eccentrically placed receiving probe 120 is the cross-sectional area at

22, the path of the ultrasonic beam U is shown in the case where the subject E is not inspected. When there is an object E to be inspected, since the ultrasonic beam U is refracted on the surface of the object E, the ultrasonic beam U propagates along a path different from the path indicated by the broken line. Here, as shown in FIG. 22, the beam incident area T2 of the eccentrically arranged receiving probe 120 on the subject E is larger than the beam incident area T1 of the transmission probe 110 on the subject E. . By doing this, the convergence of the eccentrically placed receiving probe 120 can be made more gentle than the convergence of the transmission probe 110.

Also, the focal length R2 of the eccentrically placed receiving probe 120 is longer than the focal length R1 of the transmitting probe 110 . Even in this way, the convergence of the eccentrically placed receiving probe 120 can be made more gentle than the convergence of the transmission probe 110. At this time, the distances from the subject E to the transmitting probe 110 and the eccentrically arranged receiving probe 120 are all the same, for example, but need not be the same.

In this way, in the sixth embodiment, the convergence of the eccentrically arranged receiving probe 120 is made more gentle than the convergence of the transmitting probe 110. That is, the focal length R2 of the eccentrically placed receiving probe 120 is set longer than the focal length R1 of the transmitting probe 110. As a result, since the beam incident area T2 of the eccentrically arranged receiving probe 120 is widened, a wide range of scattered waves U1 can be detected. As a result, even if the propagation path of the scattered wave U1 changes slightly, the scattered wave U1 can be detected by the eccentrically arranged receiving probe 120 . As a result, a wide range of defective parts D can be detected.

In addition, the focal point of the eccentrically placed receiving probe 120 exists on the side of the transmitting probe 110 (upper in the example of illustration) than the focal point of the transmitting probe 110. By shifting the focus in this way, it is possible to easily receive the scattered wave U1 with the eccentrically arranged receiving probe 120, and it is possible to easily detect the scattered wave U1.

In addition, as the eccentric arrangement receiving probe 120, the probe of the non-converged type used in the 1st embodiment may be used. Since the focal length R2 of the non-converging type probe is infinite, it is longer than the focal length R1 of the transmission probe 110. That is, even for the non-converging eccentrically placed receiving probe 120, the convergence of the eccentrically placed receiving probe 120 is gentler than that of the transmitting probe 110.

(Seventh Embodiment)

Fig. 23 is a diagram showing an example of an eccentrically arranged receiving probe 120 according to the seventh embodiment. It is a plan view of the ultrasound examination apparatus Z, the transmitting probe 110, and the eccentrically disposed receiving probe 120 as viewed from the minus side of the z-axis. That is, FIG. 23 is a view seen from the side of the eccentrically placed receiving probe 120. In the third embodiment, the length b of the eccentric direction of the receiving sound axis AX2 with respect to the transmission sound axis AX1 of the vibrator 111 (FIG. 3) of the eccentrically arranged receiving probe 120 is The direction along the surface is also longer than the length a in the direction orthogonal to the direction of eccentricity. The lengths a and b are characteristic lengths, and mean the lengths of the sides of the rectangle in the case of a rectangular oscillator, and mean the major axis or the minor axis of the ellipse in the case of an elliptical oscillator, respectively.

When the aspect ratio of the eccentrically placed receiving probe 120 is set in this way, the scattered wave U1 is detected by the eccentrically placed receiving probe 120 even if the arrival position of the scattered wave U1 changes due to a change in the depth of the defective portion D. can do.

The scattered wave U1 is scattered in a radial direction with the transmission sound axis AX1 as the center. Therefore, when the eccentrically placed receiving probe 120 is disposed at the position shown in FIG. 23 , the scattered wave U1 is scattered in the longitudinal direction of the eccentrically placed receiving probe 120 (the extension direction of “length b”). In other words, the extension direction of "length b" is the direction in which the scattered wave U1 is radiated. Therefore, by increasing the value of "length b", it is possible to detect the scattered wave U1 scattered at the defect portion D of various depths or the like. That is, even if the arrival position of the scattered wave U1 changes due to a change in the depth of the defect D, the scattered wave U1 can be detected by the eccentrically arranged receiving probe 120 .

There are no restrictions on the lengths a and b, and the length b is longer than the length a, that is, as long as 1 < b/a, but the upper limit b/a (length b divided by length a) is, for example, 100 or less, preferably 100 or less. at least 50 or less.

In addition, although FIG. 23 shows the eccentrically placed receiving probe 120 as the eccentrically placed receiving probe 120, a rectangular parallelepiped (rectangular shape) is shown. lose

(Eighth Embodiment)

24 is a diagram showing the configuration of the scanning measurement device 1 of the ultrasonic inspection device Z according to the eighth embodiment. In the eighth embodiment, the scanning measurement device 1 includes an installation angle adjusting unit 106 that adjusts the inclination of the eccentrically placed receiving probe 120 . Accordingly, the intensity of the received signal can be increased, and the SN ratio (Signal to Noise ratio, signal-to-noise ratio) of the signal can be increased. Although not shown, the installation angle adjustment part 106 is comprised by an actuator, a motor, etc., for example.

Here, the angle θ formed by the transmission sound axis AX1 and the reception sound axis AX2 is defined as a receiving probe installation angle. In the case of FIG. 24, since the transmission probe 110 is installed in the vertical direction, the transmission sound axis AX1 is in the vertical direction, so the angle θ, which is the installation angle of the receiving probe, is eccentrically arranged and received with the transmission sound axis AX1 (ie, the vertical direction). This is the angle formed by the normal line of the probe 120. Then, by the installation angle adjustment unit 106, the angle θ is tilted to the side where the transmission sound axis AX1 exists, and the angle θ is set to a value larger than zero. That is, the eccentric arrangement receiving probe 120 is inclined. Specifically, the eccentrically placed receiving probe 120 is tilted so as to satisfy 0°<θ<90°, and the angle θ is, for example, 10°, but is not limited thereto.

In addition, the eccentric distance L in the case of arranging the eccentrically placed receiving probe 120 at an angle is defined as follows. An intersection point C2 between the receiving sound axis AX2 and the transducer surface of the eccentrically arranged receiving probe 120 is defined. Also, an intersection C1 between the transmission sound axis AX1 and the transducer surface of the transmission probe 110 is defined. The distance between the coordinate position (x4, y4) obtained by projecting the position of the intersection point C1 onto the xy plane and the coordinate position (x5, y5) obtained by projecting the position of the intersection point C2 onto the xy plane is defined as the eccentric distance L.

As a result of actually detecting the defect D by arranging the eccentric receiving probe 120 in this manner, the signal strength of the received signal increased three times compared to the case where θ = 0.

25 is a diagram explaining the reason why the effect according to the eighth embodiment occurs. The scattered wave U1 propagates in a direction away from the transmission sound axis AX1. Therefore, as shown in FIG. 25, when the scattered wave U1 reaches the outside of the object E, the normal vector of the surface of the object E is at an angle α2 of non-zero angle with the object E. enters the interface with the outside. And, the angle of the scattered wave U1 emitted from the surface of the object E to be inspected has an angle β2 which is a non-zero emission angle with respect to the normal direction of the surface of the object E to be inspected. The scattered wave U1 can be received most efficiently when the normal vector of the transducer surface of the eccentrically arranged receiving probe 120 matches the traveling direction of the scattered wave U1. That is, the received signal strength can be increased by arranging the eccentrically arranged receiving probe 120 at an angle.

Further, when the angle β2 of the ultrasonic beam U emitted from the object E to be inspected coincides with the angle θ formed by the transmission sound axis AX1 and the reception sound axis AX2, the reception effect is the highest. However, since the effect of increasing the received signal is obtained even when the angle β2 and the angle θ do not completely coincide, as shown in FIG. 25, the angle β2 and the angle θ do not have to completely coincide.

In addition, in the scanning measuring device 1 ( FIG. 24 ), an installation angle adjusting unit 106 is provided, and an eccentric arrangement receiving probe 120 is installed by the installation angle adjusting unit 106 . The receiving probe installation angle of the eccentrically disposed receiving probe 120 can be adjusted by the installation angle adjusting unit 106 . Since the path of the scattered wave U1 changes somewhat depending on the material, thickness, etc. of the object E to be inspected, the optimal value of the installation angle of the eccentrically placed receiving probe 120 also changes. Therefore, by allowing the installation angle adjuster 106 to adjust the installation angle of the receiving probe, the installation angle of the eccentrically disposed receiving probe 120 can be appropriately adjusted according to the material, thickness, etc. of the object E to be inspected.

Further, in the eighth embodiment, the eccentrically placed receiving probe 120 is disposed in an inclined state with respect to the horizontal plane, but the transmitting probe 110 may also be disposed in an inclined state. Alternatively, the transmission probe 110 may be arranged in a state of inclination with respect to the horizontal plane, and the transducer surface of the eccentric arrangement receiving probe 120 may be arranged so as to be parallel to the horizontal plane (xy plane). In either case, as shown in Fig. 2B above, the transmission sound axis AX1 and the reception sound axis AX2 are arranged in a shifted state.

In addition, in order to obtain the effect of the inclined arrangement described in this embodiment, the angle θ (inclination angle) is set in the range of 0°<θ<90°. On the other hand, in another embodiment of the present disclosure, it goes without saying that θ=0° may be sufficient.

(Ninth Embodiment)

26 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a ninth embodiment. In the ninth embodiment, the eccentric arrangement receiving probe 120 includes a plurality of unit probes 120a. In the illustrated example, the number of unit probes 120a is three. The unit probes 120a are disposed at positions having different eccentric distances L (distance from the transmission sound axis AX1).

Depending on the depth, shape, inclination, etc. of the defect portion D, the path of the scattered wave U1 changes slightly. For example, the scattering angle (the angle formed by the scattered wave U1 with respect to the transmission sound axis AX1) during scattering is usually about the same. For this reason, the deeper the defect D is, the scattered wave U1 arrives at a place closer to the transmission sound axis AX1, and the shallower the defect D is, the scattered wave U1 arrives at a place farther from the transmission sound axis AX1. reach Therefore, by using the plurality of unit probes 120a, information about the defect portion D (the depth of the defect portion D, etc.) You can get it.

As the plurality of unit probes 120a, an array type probe 122 (Figs. 28 and 29) in which a plurality of sound sensing elements 122a (Figs. 28 and 29) are housed in one housing may be used. In this case, each of the unit probes 120a in Fig. 26 corresponds to the sensing element, and they are accommodated in one housing. A damping element is an element that converts ultrasonic waves into electrical signals. As the sound sensing element, a capacitive micro-machined ultrasonic transducer (CMUT) or the like may be used in addition to the piezoelectric element.

27 is a functional block diagram of an ultrasonic inspection apparatus Z according to a ninth embodiment. A plurality of unit probes 120a are connected to respective receiving systems 220c, 220d, and 220e. The configuration of each receiving system 220c, 220d, and 220e is the same as that of the receiving system 220 shown in FIG. 10 . That is, the receiving systems 220c, 220d, and 220e all include the signal amplifier 222, the waveform analysis unit 221, and the phase extraction unit 231 as shown in FIG. 10 (not shown in FIG. 27). provide A signal from each unit probe 120a is amplified by a signal amplifier 222 and input to a waveform analysis unit 221 and a phase extraction unit 231 . The waveform analyzer 221 outputs the amplitude of the received signal (scattered wave U1), and the phase extractor 231 outputs phase information of the received signal (scattered wave U1). The output from each of these reception systems 220c, 220d, and 220e is input to the defect information determination unit 205.

The defect information determination unit 205 is provided in the control device 2, and among the plurality of unit probes 120a, scattering of the irradiated ultrasonic beam U at the defect portion D of the inspected object E is performed. Based on the received signal of the unit probe 120a that receives the scattered wave U1 generated by . Specifically, the defect information determining unit 205 receives optimum reception for observing the scattered wave U1 based on the amplitude information from the waveform analyzing unit 221 in each of the receiving systems 220c, 220d, and 220e. System 220 is determined. In the ninth embodiment, the defect information determining unit 205 selects the receiving system 220 having the largest amplitude. Then, the phase information from the phase extraction unit 231 of the selected receiving system 220 is output to the data processing unit 201.

The defect information determining unit 205 determines the information regarding the defective unit D based on the waveform analysis result in each of the receiving systems 220c, 220d, and 220e. Based on the received signal is how much of the received signal (scattered wave U1) was detected by which unit probe 120a. By doing in this way, the precision of the positional information of the defective part D can be improved.

The output of the defect information determination unit 205 is input to the data processing unit 201 . The data processing unit 201 includes a phase change amount calculating unit 232 . The phase change calculation unit 232 calculates the phase change amount of the received signal with respect to the scan position change by matching with the scan position information from the scan controller 204 that scans the probe. As described above, the amount of phase change associated with this scan position change gives an image corresponding to the contour information of the defective portion D. This information is visualized and displayed on the display device 3.

In addition, the defect information determining unit 205 may be provided as a part of the data processing unit 201 .

(Tenth Embodiment)

Fig. 28 is a diagram showing the arrangement of the eccentrically placed receiving probes 120 in the tenth embodiment. In this example, it is a plan view of the transmitting probe 110 and the eccentrically placed receiving probe 120 viewed from the minus side of the z-axis in Fig. 1, that is, from the eccentrically placed receiving probe 120 side. In the tenth embodiment, the eccentrically arranged receiving probes 120 are two-dimensionally arranged in the xy plane direction. That is, the eccentric arrangement receiving probe 120 includes a plurality of unit probes 120a having a rectangular shape when viewed in plan, and the plurality of unit probes 120a are radially arranged with the transmission sound axis AX1 as the center. In the illustrated example, the number of unit probes 120a is 8.

The direction of the scattered wave U1 changes somewhat depending on the shape of the defect D, the direction of inclination, and the like. Therefore, as shown in FIG. 28, by arranging the unit probes 120a radially and recording in which direction the scattered wave U1 was detected, information such as the shape and tilt direction of the defect portion D can be obtained with more precision. can get high.

(Eleventh Embodiment)

Fig. 29 is a diagram showing the arrangement of the eccentrically arranged receiving probes 120 in the eleventh embodiment, in which the unit probes 120a are arranged at an angle. A plurality of unit probes 120a are arranged symmetrically with respect to the transmission sound axis AX1. Therefore, at least two unit probes 120a are disposed at the same eccentric distance L. In the illustrated example, three unit probes 120a are symmetrically disposed on both sides of the transmission sound axis AX1 when viewed from the plane including the transmission sound axis AX1. Then, two unit probes 120a are disposed at each position of three different eccentric distances L. Also, the unit probes 120a are arranged obliquely, similarly to the eighth embodiment (Fig. 25).

30 is a diagram showing the arrangement of eccentrically arranged receiving probes 120 in the eleventh embodiment, and is a view in which the unit probes 120a are arranged in the vertical direction. A set of unit probes 120a are arranged symmetrically with respect to the transmission sound axis AX1. Therefore, at least two unit probes 120a are disposed at the same eccentric distance L.

By disposing at least two unit probes 120a at the same eccentric distance L, the scattered waves U1 scattered in a plurality of directions can be detected. In addition, when viewed from a plane including the transmission sound axis AX1 (FIGS. 29 and 30), by disposing at least two unit probes 120a on both sides of the transmission sound axis AX1, a wide range of scattered waves U1 is received. can do. In addition, when the scattered wave U1 is detected by the unit probes 120a on both sides, the controller 2 actually detects the defective portion D, and when the scattered wave U1 is detected only on either side, an error occurs. can be determined. Thereby, the detection accuracy of the defective part D can be improved.

(Twelfth Embodiment)

31 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a twelfth embodiment. In the twelfth embodiment, the focal length R3 of the coaxially placed receiving probe 140 is shorter than the focal length R2 of the eccentrically placed receiving probe 120 . As a result, the convergence of the coaxially placed receiving probe 140 is higher than that of the eccentrically placed receiving probe 120 .

By making the focal length R3 of the coaxially placed receiving probe 140 shorter than the focal length R2 of the eccentrically placed receiving probe 120, among the ultrasonic beams U emitted from the transmitting probe 110, the ultrasonic beam on the receiving sound axis AX2 (U) can be efficiently received by the coaxial arrangement receiving probe 140 . On the other hand, since the scattered wave U1 has a plurality of propagation paths, the eccentrically arranged receiving probe 120 receiving the scattered wave U1 can sufficiently receive the scattered wave U1 by reducing convergence. For this reason, defects can be detected more efficiently by using the receiving probe 121 having convergence characteristics matched to the respective characteristics of the direct wave U3 and the scattered wave U1.

(13th embodiment)

32 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a thirteenth embodiment. In the thirteenth embodiment, an array type probe 122 having functions of both the eccentric arrangement receiving probe 120 and the coaxial arrangement receiving probe 140 is used. The array type probe 122 is a receiving probe in which a plurality of sensing elements 122a (also functioning as unit probes 120a (FIG. 26)) are disposed in a one-dimensional target (FIG. 32) or two-dimensionally (FIG. 33). 121).

In the array type probe 122, the reception sound axis AX2 of one sound sensing element 122a constituting it is arranged so as to coincide with the transmission sound axis AX1. The sound sensing element 122a disposed at this position functions as the coaxial arrangement receiving probe 140. Similar to the example shown in FIG. 26, the remaining sound attenuation elements 122a are arranged continuously and symmetrically in the left and right directions of the paper in FIG. 32 centered on the transmission sound axis AX1, 120). In this example, the damping elements 122a are arranged one-dimensionally.

By using the array type probe 122 and arranging the sound sensing elements 122a one-dimensionally, since the number of installed sound sensing elements 122a is small, the installation cost of the array type probe 122 can be reduced, and furthermore, The scattered wave U1 may be received by the plurality of damping elements 122a. Further, even when the defective portion D is small and the propagation of ultrasonic waves is completely blocked, the attenuating element 122a having the reception sound axis AX2 coincident with the transmission sound axis AX1 can detect a decrease in the signal amount. Thereby, it is possible to detect efficiently from the small defective portion D to the large defective portion D.

(14th embodiment)

33 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a fourteenth embodiment. FIG. 33 is a plan view of the transmission probe 110 and the array type probe 122 viewed from the minus side of the z-axis in FIG. 1, that is, from the side of the array type probe 122. As shown in FIG. 32, the sensing elements 122a constituting the array type probe 122 are one-dimensionally arranged in only one direction. However, in the array type probe 122 shown in Fig. 33, the sensing elements 122a are two-dimensionally arranged in two xy directions. In the illustrated example, the same number of damping elements 122a are arranged in each of the xy directions (seven pieces), and are arranged in a square shape. However, the sound sensing element 122a is not limited to the arrangement of a square shape, and may be arranged in each shape, such as a rectangle, a circle, and an ellipse, for example.

By using the array type probe 122 and two-dimensionally arranging the attenuating elements 122a, the scattered wave U1 can be received by most of the attenuating elements 122a, and detection leakage of the scattered wave U1 is suppressed. can do. Further, even when the defect portion D is large and the propagation of ultrasonic waves is completely blocked, the attenuating element 122a having the reception sound axis AX2 coincident with the transmission sound axis AX1 can detect a decrease in the signal amount. Thereby, it is possible to detect efficiently from the small defective portion D to the large defective portion D.

In each of the above embodiments, an example in which the defective portion D is a cavity is described, but the defective portion D may be a foreign material mixed with a material different from that of the inspected object E. Also in this case, since there is a difference (Gap) in acoustic impedance at the interface where different materials are in contact, scattered waves (U1) are generated, so the configuration of each of the above embodiments is effective. Although the ultrasonic inspection apparatus Z according to the present embodiment is premised on an ultrasonic defect imaging apparatus, it may be applied to a non-contact inline internal defect inspection apparatus.

The present disclosure is not limited to the above-described embodiments, and includes various modified examples. For example, the embodiments described above have been described in detail to easily understand the present disclosure, and are not necessarily limited to those having all of the described configurations. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to add/delete/replace a part of the structure of each embodiment with another structure.

In addition, some or all of the above-described configurations, functions, and units constituting the block diagram may be realized as hardware by, for example, designing an integrated circuit. Further, as shown in Fig. 13, each configuration, function, etc. described above may be realized with software by a processor such as CPU 252 interpreting and executing a program for realizing each function. Information such as programs, tables, and files that realize each function is not stored in the HDD, but also in a memory, a recording device such as an SSD (Solid State Drive), an IC (Integrated Circuit) card, SD (Secure Digital) It can be stored in a recording medium such as a card or a DVD (Digital Versatile Disc).

Incidentally, in each embodiment, the control lines and information lines show what is considered necessary for explanation, and it cannot be said that all control lines and information lines are necessarily shown on the product. In practice, you may think that almost all components are connected to each other.

1: scan measuring device
101: housing
102: sample table
103: transmission probe injection unit
104: receiving probe injection unit
105: eccentric distance adjustment unit
106: installation angle adjustment unit
110: transmission probe
111: vibrator
112: backing
113: matching layer
114: probe surface
115: transmission probe housing
116: connector
117, 118: lead wire
119 Transmit/receive probe
120: eccentric arrangement receiving probe
120a: unit probe
121: receive probe
122: array type probe
122a: damping element
140: coaxial batch receiving probe
2: control unit
201: data processing unit
202: driving unit
203: position measuring unit
204: scan controller
205: defect information determining unit
210: transmission system
211: waveform generator
212: signal amplifier
220, 220a, 220b: receiving system
221: waveform analysis unit
222, 223: signal amplifier
224: amplitude image generation unit
225: image compositing unit
231: phase extraction unit
232: phase change calculation unit
235: switch
251: memory
252 CPU
253: storage
254: communication device
255: I/F
3: display device
AX1: transmission sound axis
AX2: receive sound
D: Defective part
E: test subject
F: Fluid
G: gas
G1, G2, G3, G4, G5: graph
N: wholesome
S101: release step
S102: Receiving step
S103: phase extraction step
S104: phase change calculation step
S105: Shape display step
S111, S112: step
U: ultrasonic beam
U1: scattered waves
U2: ultrasonic beam
U3: direct wave
Z: ultrasonic inspection device

Claims (19)

An ultrasonic inspection device that inspects an object to be inspected by incident an ultrasonic beam on the object to be inspected through a fluid,
A scanning measuring device for scanning and measuring the ultrasonic beam to the object to be inspected, and a control device for controlling driving of the scanning measuring device,
The scan measuring device,
A transmission probe for emitting the ultrasonic beam and an eccentrically disposed receiving probe for receiving the ultrasonic beam,
the eccentrically placed receiving probe is arranged such that an eccentric distance between a transmission sound axis of the transmission probe and a reception sound axis of the eccentrically placed receiving probe is greater than zero;
The control device,
a phase extractor extracting signal phase information of the ultrasonic beam received by the eccentrically placed receiving probe;
Equipped with a phase change calculation unit for calculating a phase change amount with respect to a scanning position of the extracted phase information
ultrasound examination device. According to claim 1,
The ultrasonic inspection apparatus according to claim 1 , wherein the eccentric distance is set to a distance capable of receiving a scattered wave generated by scattering of the ultrasonic beam at a defective portion of the inspected object. According to claim 1 or 2,
The eccentricity distance is set so that the intensity of the received signal from the eccentrically placed receiving probe when incident on the defective portion of the object to be inspected is greater than the intensity of the received signal when incident on the sound portion of the object to be inspected. inspection device. According to claim 1 or 2,
The ultrasonic inspection apparatus according to claim 1 , wherein the eccentricity distance is set to a distance at which a received signal other than noise is not detected when the sound portion of the inspected object is irradiated. According to claim 1 or 2,
and an eccentric distance adjusting unit for adjusting the position of at least one of the transmitting probe and the eccentrically disposed receiving probe. According to claim 1 or 2,
The ultrasonic inspection apparatus according to claim 1, wherein a focal length of the eccentrically placed receiving probe is longer than a focal length of the transmitting probe. According to claim 1 or 2,
The ultrasound examination apparatus according to claim 1, wherein a focal point of the eccentrically placed receiving probe is on a side of the transmission probe rather than a focal point of the transmission probe. According to claim 1 or 2,
The ultrasonic inspection apparatus according to claim 1 , wherein a beam incident area of the eccentrically placed receiving probe on the inspected object is larger than a beam incident area of the transmitting probe on the inspected object. According to claim 1 or 2,
The scanning measuring device comprises an installation angle adjusting unit for adjusting the inclination of the eccentrically arranged receiving probe so that an angle θ between the transmission sound axis and the reception sound axis satisfies 0°<θ<90°. inspection device. According to claim 1 or 2,
The eccentrically arranged receiving probes include a plurality of unit probes. According to claim 10,
The control device controls the object to be inspected based on a received signal of the unit probe that receives a scattered wave generated by scattering of the irradiated ultrasound beam at a defective portion of the object to be inspected, among the plurality of unit probes. An ultrasonic inspection apparatus characterized by comprising a defect information determining unit for determining information on a defective portion of the. According to claim 1 or 2,
The ultrasonic inspection device according to claim 1, wherein the scan measuring device includes a coaxially placed receiving probe disposed at a position where the eccentric distance is zero. According to claim 12,
The control device,
A first image showing the position of a defect inside the object to be inspected, generated based on the amplitude of the direct wave received by the coaxially placed receiving probe;
A second image showing the outline of a defect inside the inspected object, generated by the phase change calculation unit based on the phase change amount with respect to the scanning position.
An ultrasonic inspection apparatus characterized by comprising an image synthesizing unit for synthesizing. According to claim 1 or 2,
The ultrasonic inspection apparatus according to claim 1, wherein the transmission probe is a transmission/reception probe that emits the ultrasonic beam and receives a reflected wave from the object to be inspected. According to claim 14,
The control device,
A first image showing the position of a defect inside the object to be inspected, generated based on the amplitude of the direct wave received by the transmission/reception probe;
A second image showing the outline of a defect inside the inspected object, generated by the phase change calculation unit based on the phase change amount with respect to the scanning position.
An ultrasonic inspection apparatus characterized by comprising an image synthesizing unit for synthesizing. According to claim 1 or 2,
The ultrasonic inspection apparatus, characterized in that the fluid is a gas. An ultrasonic inspection method for inspecting an object to be inspected by incident an ultrasonic beam on the object to be inspected through a fluid,
An emission step for emitting an ultrasonic beam from the transmission probe;
In the eccentric arrangement receiving probe having a reception sound axis at a position different from the transmission sound axis of the transmission probe, a receiving step for receiving the ultrasonic beam;
a phase extraction step of extracting signal phase information of the ultrasonic beam received by the eccentrically placed receiving probe;
and a phase change amount calculation step of calculating a phase change amount with respect to a scanning position of the extracted phase information.
Ultrasonic examination method, characterized in that. According to claim 17,
And a shape display step of displaying the shape of the defective portion of the inspected object by determining whether the phase change amount with respect to the scanning position of the phase information generated in the phase change amount calculation step is equal to or greater than a preset threshold value. Ultrasonic examination method, characterized in that. The method of claim 17 or 18,
The ultrasonic inspection method, characterized in that the fluid is a gas.

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