TWI793693B - Ultrasonic inspection device and ultrasonic inspection method - Google Patents

Abstract

The present disclosure provides an ultrasonic inspection device having excellent detection performance of a defective portion, for example, a display image with excellent resolution. For this reason, the ultrasonic inspection device Z has: a scanning measurement device 1, which scans and measures the ultrasonic beam on the object to be inspected; and a control device 2, which controls the driving of the scanning measurement device 1; The sending probe 110 of the sound beam, and the eccentrically arranged receiving probe 120 for receiving the ultrasonic beam are arranged in such a way that the eccentric distance between the sending sound axis of the sending probe 110 and the receiving sound axis of the eccentrically arranged receiving probe 120 is greater than zero. The receiving probe 120 is arranged eccentrically, and the control device 2 is provided with: a phase acquisition part 231, which extracts the phase information of the signal of the ultrasonic beam received by the receiving probe 120 arranged eccentrically; The phase variation relative to the scanning position of the retrieved phase information.

Description

Ultrasonic inspection device and ultrasonic inspection method

The disclosure relates to an ultrasonic inspection device and an ultrasonic inspection method.

A method of inspecting a defect portion of an object to be inspected using ultrasonic beams is known. For example, when there is a defect (cavity, etc.) with low acoustic impedance such as air inside the object to be inspected, a gap of acoustic impedance is generated inside the object to be inspected, so the amount of transmission of the ultrasonic beam becomes small. Therefore, it is possible to detect defects inside the object to be inspected by measuring the transmission amount of the ultrasonic beam.

The technique described in Patent Document 1 is known about an ultrasonic inspection device. In the ultrasonic inspection device described in Patent Document 1, a rectangular wave burst signal including a specific number of consecutive negative rectangular waves is applied to a transmitting ultrasonic probe disposed opposite to the subject through air. The receiving ultrasonic probe arranged opposite to the subject through air separation will convert the ultrasonic waves propagating in the subject into transmitted wave signals. Based on the signal level of the transmitted wave signal, it is determined whether the object is defective. In addition, the acoustic impedance of the transmitting ultrasonic probe and the receiving ultrasonic probe mounted on the vibrator and the front panel of the ultrasonic transmitting and receiving side of the vibrator is set to be lower than that of a contact type ultrasonic probe used in contact with the subject. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2008-128965 (especially abstract)

[Problem to be solved by the invention]

In the ultrasonic inspection device described in Patent Document 1, when observing a minute defect in an object to be inspected, there is a problem that the resolution of the image of the observed defect decreases. That is, there is a problem that the outline of the image corresponding to the defective portion is blurred. The reason for this is that when a part of the ultrasonic beam is blocked by a defect, the received signal also changes. This problem is particularly noticeable when the size of the defect to be detected is about the same as the size (beam diameter) of the ultrasonic beam, or is smaller. The problem to be solved by the present disclosure is to provide an ultrasonic inspection device and an ultrasonic inspection method with excellent detection performance of defective parts, for example, the resolution of displayed images. [Technical means to solve the problem]

The ultrasonic inspection device of the present disclosure performs the inspection of the object to be inspected by incident ultrasonic beams on the object through a fluid, and includes: a scanning measurement device that scans the object to be inspected with the ultrasonic beam and measurement; and a control device, which controls the driving of the above-mentioned scanning measurement device; the above-mentioned scanning measurement device has a sending probe that emits the above-mentioned ultrasonic beam and an eccentrically arranged receiving probe, and the sending sound axis of the above-mentioned sending probe and the above-mentioned eccentrically arranged In the way that the eccentric distance of the receiving sound axis of the receiving probe is greater than zero, the above-mentioned eccentric configuration receiving probe is arranged. The above-mentioned control device is related to an ultrasonic inspection device, and the ultrasonic inspection device includes: a phase acquisition unit that acquires phase information of a signal of the above-mentioned ultrasonic beam received by the above-mentioned eccentrically arranged receiving probe; and a phase change calculation unit , which calculates the variation of each scanning position of the extracted phase information. Other solutions will be described later in the forms for implementing the invention. [Effect of 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 defective parts, for example, the resolution of displayed images.

Hereinafter, modes for implementing the present disclosure (referred to as embodiments) will be described with reference to the drawings. However, the present disclosure is not limited to the following embodiments. For example, different embodiments may be combined or arbitrarily changed within a range that does not significantly impair the effects of the present disclosure. In addition, the same code|symbol is attached|subjected to the same member, and repeated description is abbreviate|omitted. In addition, the same name is attached|subjected to what has the same function. The contents of the illustrations are only schematic. For the convenience of illustrations, the actual configuration may be changed within the scope of not obviously impairing the effect of this disclosure.

(first embodiment) Fig. 1 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a first embodiment. In FIG. 1 , a scanning measurement device 1 is shown schematically in cross section. In FIG. 1 , an orthogonal three-axis coordinate system is shown including the x-axis as the horizontal direction on the paper, the y-axis as the orthogonal direction on the paper, and the z-axis as the vertical direction on the paper.

The ultrasonic inspection apparatus Z is a person who inspects the object E by injecting the ultrasonic beam U ( FIG. 3 ) on the object E 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 subject E exists in the fluid F. In the first embodiment, as the fluid F, air (an example of the gas G) is used. Therefore, the inside of the casing 101 of the scanning measurement device 1 becomes a cavity filled with air. As shown in FIG. 1 , an 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 measurement device 1 is for scanning and measuring an object E with an ultrasonic beam U, and includes a sample table 102 fixed to a casing 101 , and the object E is placed on the sample table 102 . The object E to be inspected is made of any material. The object E to be inspected is, for example, a solid material, more specifically, a composite material such as metal, glass, resin material, or CFRP (Carbon-Fiber Reinforced Plastics). Moreover, in the example of FIG. 1, the object E has a defect part D inside. The defective portion D is a cavity or the like. Examples of the defective portion D are cavities, foreign materials different from the original materials, and the like. In the test object E, the part other than the defective part D is called a healthy part N.

Since the constituent materials of the defective part D and the healthy part N are different, the acoustic impedance between them is different, and the propagation characteristic of the ultrasonic beam U changes. The ultrasonic inspection apparatus Z observes this change, and detects the defective part D.

The scanning measurement device 1 has a sending probe 110 emitting an ultrasonic beam U, and a receiving probe 120 arranged eccentrically. The transmitting probe 110 is installed in the casing 101 via the transmitting probe scanning unit 103 , and emits the ultrasonic beam U. The receiving probe 120 arranged eccentrically is the receiving probe 121 that is installed on the opposite side of the transmitting probe 110 relative to the object E to receive the ultrasonic beam U. The eccentrically arranged receiving probe 120 has a receiving sound axis AX2 at a position different from the sending sound axis AX1 of the sending probe 110 . The distance between the sending sound axis AX1 and the receiving sound axis AX2 is the eccentric distance L. The receiving probe 120 arranged eccentrically is provided in the casing 101 via the receiving probe scanning unit 104 .

In addition, in this specification, among the receiving probes 121 that receive the ultrasonic beam U, those that are arranged at a position where the eccentric distance L is greater than zero are defined as eccentrically arranged receiving probes 120, and those that are arranged at a position where the eccentric distance L is zero are defined as The receive probe 140 is configured coaxially (FIG. 2A etc.). In other words, the term receiving probe 121 includes the eccentrically arranged receiving probe 120 and the coaxially arranged receiving probe 140 , and is the name of a probe that receives ultrasonic waves regardless of the eccentric distance L.

Here, "the side opposite to the sending probe 110" means the space on the opposite side (the opposite side in the z-axis direction) to the space where the sending probe 110 is located among the two spaces separated by the object E, x , The y coordinates do not mean the same opposite side (ie, a symmetrical position with respect to the xy plane). As shown in FIG. 1 , the sending probe 110 and the receiving probe 120 are arranged eccentrically in such a way that the sending sound axis AX1 and the receiving sound axis AX2 are offset by an eccentric distance L. In addition, the specific content of the sending sound axis AX1, the receiving sound axis AX2, and the eccentric distance L will be described below.

By moving the receiving probe scanning unit 104, the receiving probe 120 arranged eccentrically scans the sample table 102 in the x-axis direction and the y-axis direction. The transmitting probe 110 and the eccentrically arranged receiving probe 120 are scanned while maintaining the eccentric distance L in the x-axis direction or the y-axis direction across the object E (thick double arrow).

In addition, in the scanning measurement device 1, the details are described below, but the eccentric distance L is set as follows. That is, the eccentric distance L is set as a distance capable of receiving the scattered wave U1 of the ultrasonic beam U caused by scattering of the defect portion D of the object E to be inspected. Alternatively, the eccentricity distance L is set so that the received signal intensity of the eccentrically arranged receiving probe 120 when incident on the defective part D of the subject E is greater than the received signal strength when incident on the healthy part N of the subject E. Alternatively, the eccentric distance L is set as a distance at which a received signal other than noise is not detected when the healthy part N of the subject E is irradiated.

The scanning measurement device 1 is equipped with an eccentric distance adjustment unit 105, which adjusts the position of at least one of the transmitting probe 110 or the eccentrically arranged receiving probe 120 such that the eccentric distance L between the transmitting sound axis AX1 and the receiving sound axis AX2 is greater than zero. The receiving probe scanning unit 104 provided in the casing 101 is equipped with an eccentric distance adjusting unit 105 (eccentric distance adjusting mechanism). Furthermore, the eccentric distance adjustment unit 105 is provided with an eccentric arrangement receiving probe 120 . With the eccentric distance adjustment part 105, the receiving probe 120 can be moved independently from the position of the receiving probe scanning part 104, and the offset between the receiving sound axis AX2 and the sending sound axis AX1 can be set as the eccentric distance L. In addition, the eccentric distance adjustment unit 105 may be provided on the sending probe scanning unit 103 side. That is, since it only needs to be set so that the offset between the receiving sound axis AX2 and the sending sound axis AX1 becomes the eccentric distance L, the eccentric distance adjusting part 105 may be installed on the side of the receiving probe 121 or may be installed on the sending probe. 110 side.

A control device 2 is connected to the scanning measurement device 1 . The control device 2 controls the driver of the scanning measurement device 1 and controls the movement (scanning) of the sending probe 110 and the eccentrically arranged receiving probe 120 by issuing instructions to the sending probe scanning unit 103 and the receiving probe scanning unit 104 . By synchronously moving the sending probe scanning unit 103 and the receiving probe scanning unit 104 in the x-axis direction and the y-axis direction, the sending probe 110 and the eccentrically arranged receiving probe 120 scan the object to be inspected in the x-axis direction and the y-axis direction e. Furthermore, the control device 2 emits the ultrasonic beam U from the sending probe 110 , and performs waveform analysis based on the signal obtained from the eccentrically arranged receiving probe 120 .

In addition, in this embodiment, the state where the object E is fixed to the casing 101 via the sample table 102, that is, the state where the object E is fixed to the casing 101, and the transmitting probe 110 and the receiving probe eccentrically arranged are shown. 120 for example scanning. Contrary to this, a configuration may be adopted in which the transmitting probe 110 and the receiving probe 120 are arranged eccentrically to the housing 101, and the subject E is moved to perform scanning.

In the example shown in the figure, gas G (an example of fluid F. It may also be liquid W (Fig. 17)) is interposed between the transmitting probe 110 and the object E, and between the eccentrically arranged receiving probe 120 and the object E . Therefore, since the transmitting probe 110 and the eccentrically arranged receiving probe 120 can be inspected without contacting the object E, the relative position in the xy plane direction can be changed smoothly and at high speed. That is, by interposing the fluid F between the transmitting probe 110 and the eccentrically arranged receiving probe 120 and the object E, smooth scanning can be realized.

The transmission probe 110 is a bundle type transmission probe 110 . On the other hand, the eccentric arrangement of the receiving probe 120 uses a probe that is looser in bunching than the transmitting probe 110 . In this embodiment, the eccentrically arranged receiving probe 120 uses a non-bundling type probe whose probe surface is a flat surface. By using such a non-bundling type eccentric arrangement receiving probe 120, information on the defect portion D can be collected in a wide range.

In this embodiment, relative to the sending probe 110, the receiving probe 120 is arranged eccentrically by the eccentric distance L in the x-axis direction of FIG. Receive probe 120 . Alternatively, it is also possible to arrange the eccentricity by shifting L1 in the x-axis direction and shifting L2 in the y-axis direction (that is, if the position of the transmitting probe 110 on the xy plane is taken as the origin, then the position is (L1, L2)). Receive probe 120 is configured.

Fig. 2A is a diagram illustrating the sending sound axis AX1, the receiving sound axis AX2 and the eccentric distance L, and it is the case where the sending sound axis AX1 and the receiving sound axis AX2 extend in the vertical direction. 2B is a diagram illustrating the sending sound axis AX1, the receiving sound axis AX2 and the eccentric distance L, and it is the case where the sending sound axis AX1 and the receiving sound axis AX2 extend obliquely.

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

Also, the receiving sound axis AX2 is defined as the sound axis of the propagation path of the virtual ultrasonic beam when the receiving probe 120 is assumed to be eccentrically arranged to emit the ultrasonic beam U. In other words, the receiving sound axis AX2 is the central axis of the virtual ultrasonic beam U when the receiving probe 120 is assumed to be eccentrically arranged to emit the ultrasonic beam U.

As a specific example, the case where the probe surface is a planar non-bundle receiving probe will be described. In this case, the direction of the receiving sound axis AX2 is the normal direction of the probe face, and the axis passing through the center point of the probe face is the receiving sound axis AX2. When the probe surface is rectangular, its center point is defined as the intersection of the diagonals of the rectangle.

The reason why the direction of the receiving sound axis AX2 is the normal direction of the probe surface is that the virtual ultrasonic beam U radiated from the receiving probe 121 is emitted toward the normal direction of the probe surface. In the case of receiving the ultrasonic beam U, the ultrasonic beam U incident in the normal direction of the probe surface can also be received with good sensitivity.

The eccentric distance L is defined as the offset distance between the sending sound axis AX1 and the receiving sound axis AX2. Therefore, as shown in FIG. 2B , when the ultrasonic beam U emitted from the sending probe 110 is refracted, the eccentric distance L is defined as the offset distance between the refracted sending sound axis AX1 and the receiving sound axis AX2 . The ultrasonic inspection apparatus Z of the present embodiment adjusts the transmitting probe 110 and the eccentrically arranged receiving probe 120 by the eccentric distance adjustment unit 105 ( FIG. 1 ) so that the eccentric distance L defined in this way becomes a distance greater than zero. Thereby, the ultrasonic beam U ( FIG. 3 ) emitted from the transmitting probe 110 and passing through the defect portion D ( FIG. 1 ) can be reduced, and the signal change originating from the defect portion D of the receiving probe 121 can be easily detected.

However, in this embodiment, as a preferable example, as described above, the receiving probe 120 is arranged eccentrically to receive the scattered wave U1 generated by the scattering of the ultrasonic beam U at the defect portion D ( FIG. 6B ). Since the scattered wave U1 is generated due to the existence of the defect part D, the detection accuracy of the defect part D can be further improved by detecting the scattered wave U1. In the following example, to simplify the description, the present embodiment will be described by taking the eccentrically arranged receiving probe 120 installed at a position capable of receiving the scattered wave U1 as an example.

FIG. 2A shows the situation where the sending probe 110 is arranged in the normal direction of the surface of the object E to be inspected. In FIGS. 2A and 2B , the transmission sound axis AX1 is indicated by a solid arrow. Also, the receiving sound axis AX2 is indicated by a dot chain arrow. In addition, in FIG. 2A and FIG. 2B, the position of the receiving probe 121 shown by the dotted line is the position where the eccentric distance L is zero, and the receiving probe 121 whose transmitting sound axis AX1 is consistent with the receiving sound axis AX2 is a coaxially arranged receiving probe 140 . In addition, the receiving probe 121 shown by the solid line is the eccentrically arranged receiving probe 120 arranged at a position where the eccentric distance L is greater than zero. When the transmission probe 110 is arranged such 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 situation where the transmitting probe 110 is arranged inclined at an angle α from the normal direction of the surface of the object E to be inspected. FIG. 2B is also the same as FIG. 2A , with the solid line arrow representing the transmitting sound axis AX1 and the dot chain line arrow representing the receiving sound axis AX2 . In the case of the example shown in FIG. 2B , as described above, at the interface between the object E and the fluid F, the propagation path of the ultrasonic beam U is refracted at the refraction angle β. Therefore, the transmission sound axis AX1 is bent (refracted) as shown by the solid arrow in FIG. 2B . In this case, since the position of the coaxially arranged receiving probe 140 shown by the dotted line is located on the transmitting sound axis AX1, it is a position where the eccentric distance L is zero. Also, as described above, when the ultrasonic beam U is refracted, the receiving probe 120 is arranged eccentrically so that the distance between the transmitting sound axis AX1 and the receiving sound axis AX2 becomes L. In addition, in the example shown in FIG. 1 , since the transmitting probe 110 is installed in the normal direction of the surface of the object E, the eccentric distance L becomes as shown in FIG. 2A .

The eccentric distance L is set as the position where the signal strength of the defective part D is greater than the received signal of the healthy part N of the object E under inspection. This point will be described below.

FIG. 3 is a cross-sectional view showing the configuration of the sending probe 110 . In FIG. 3 , for simplicity, only the outline of the emitted ultrasonic beam U is shown, but actually, a large number of ultrasonic beams U are emitted toward the normal vector direction of the probe surface 114 throughout the entire area of the probe surface 114 .

The transmitting probe 110 is configured to focus the ultrasonic beam U. Thereby, the minute defect part D in the object E to be inspected can be detected with high precision. The reason why the minute defect portion D can be detected will be described below. The transmission probe 110 includes a transmission probe case 115 , and a backing 112 , a vibrator 111 , and an integration layer 113 are provided inside the transmission probe case 115 . Electrodes (not shown) are installed on the vibrator 111 , and the electrodes are connected to the connector 116 through the lead wires 118 . Moreover, the connector 116 is connected to the power supply device (not shown) and the control device 2 through the lead wire 117 . In this specification, the probe surface 114 of the sending probe 110 or the receiving probe 121 is defined as the surface of the integration layer 113 when the integration layer 113 is provided, and is defined as the surface of the vibrator 111 when the integration layer 113 is not provided. That is, the probe surface 114 is a surface that emits the ultrasonic beam U in the case of the transmitting probe 110 , and is a surface that receives the ultrasonic beam U in the case of the receiving probe 121 .

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

In FIG. 4A, no obvious signal was observed, but in FIG. 4B, after 90 microseconds after the burst wave was applied to the transmitting probe 110, a clear signal was observed. The delay of 90 microseconds until the apparent signal is observed is due to the time it takes for the ultrasonic beam U to be emitted until the scattered wave U1 reaches the off-centre receiving probe 120 . Specifically, the speed of sound in the air is 340 (m/s), while it is about 6000 (m/s) in the stainless steel constituting the object E, so a delay of 90 microseconds occurs.

Fig. 5 is a graph showing an example of plotting signal strength data. In this example, the sending probe 110 and the eccentrically arranged receiving probe 120 are used to scan the defect portion D with a width of 2 mm in the x-axis direction, and the signal extracted from the received signal at the position of the x-axis (the received signal shown in FIG. 4B ) is drawn. Intensity data (signal amplitude at each scan position). In this embodiment, the acquisition of signal strength data is performed by extracting the Peak To Peak (peak-to-peak) value of the received signal shown in FIG. 4B , that is, the difference between the maximum value and the minimum value in an appropriate time zone. As another example of the method of extracting signal strength data, the received signal shown in FIG. 4B can also be converted into frequency components by signal processing such as short-time Fourier transform, and the strength of appropriate frequency components can be extracted. Furthermore, as the signal strength data, the correlation function can also be calculated based on an appropriate reference wave. In this way, signal strength data is obtained corresponding to each scanning position of the sending probe 110 .

In the drawing of the signal intensity data shown in FIG. 5 , the cavity (defect part D) with a width of 2 mm corresponds to the symbol D1 in FIG. 5 . It can be seen that the sound part N (the part other than the symbol D1) of the subject E is a signal of noise level, while the received signal is significantly larger at the position where the defective part D exists inside (the part other than the symbol D1).

Therefore, it is preferable that the eccentric distance adjustment unit 105 adjusts the eccentric distance L so that the received signal intensity of the eccentrically arranged receiving probe 120 incident on the defective part D is greater than the received signal intensity when incident on the healthy part N. Thereby, the defective portion D can be detected based on the received signal strength. The eccentric distance L is, for example, the distance between the receiving sound axis AX2 of the eccentrically arranged receiving probe 120 and the sending sound axis AX1 of the sending probe 110 arranged at a position capable of receiving the scattered wave U1 ( FIG. 6B ). The eccentric distance adjustment unit 105 is, for example, not shown, but is composed of an actuator, a motor, and the like.

In addition, it is preferable that the eccentric distance adjusting unit 105 adjusts the eccentric distance L to a distance at which a received signal other than noise is not detected when the healthy part N is irradiated. That is, it is preferable that the eccentricity distance adjustment unit 105 sets the eccentricity distance L so that no significant reception signal is emitted in the healthy portion N of the subject E. Thereby, the SN ratio can be increased, and the location where a received signal other than noise is detected can be determined as the defective part D, and the defective part D can be detected.

The eccentric distance L can be determined using, for example, a standard sample made of the same material as the test object E and having a defect D inside. In addition, the ultrasonic beam U can be irradiated to the defect part D of the standard sample, and the eccentricity distance L can be determined based on the position where the ultrasonic beam U or the scattered wave U1 can be received.

When the transmitting probe 110 is only scanned one-dimensionally in the x-axis direction, the display device 3 displays the graph of the signal strength data shown in FIG. 5 . When the scanning direction of the transmitting 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 part D is represented as a two-dimensional image and displayed on the display device 3 .

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

As shown in FIGS. 6A and 6B , the ultrasonic beam U emitted from the transmitting 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 healthy portion N, the ultrasonic beam U passes through in a manner focused toward the transmission sound axis AX1 . Therefore, no received signal is observed in the eccentrically arranged receiving probe 120 arranged with the eccentric distance L maintained. On the other hand, as shown in FIG. 6B , when an ultrasonic beam U is incident on a defect D, the ultrasonic beam U is scattered in the defect D, and the scattered wave U1 is received by the eccentrically arranged receiving probe 120 . Therefore, a distinct received signal was observed.

In this way, the scattered wave U1 scattered by the defect portion D of the object E is observed at the eccentrically arranged receiving probe 120 . Therefore, the received signal of the defective part D is greater than the received signal of the healthy part N. That is, it is determined that the defective portion D exists in a position where the signal is large. Therefore, it is preferable that the eccentric distance adjustment unit 105 adjusts the eccentric distance L to a distance capable of receiving the scattered wave U1 of the irradiated ultrasonic beam U caused by scattering at the defect portion D of the object E to be inspected. Thereby, the scattered wave U1 peculiar to the defect part D can be detected, and the detection accuracy of the defect part D can be improved.

The eccentric distance L is preferably a length that cannot receive the ultrasonic beam U emitted from the sending probe 110 and can only selectively receive the scattered wave U1. Thereby, the SN ratio can be increased, and the detection performance of the defect part D, especially the detection sensitivity can be improved. Here, "the detection sensitivity is high" means that a defect portion D smaller than the former can be detected. That is, the lower limit of the size of the detectable defect portion D is smaller than the previous one.

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

FIG. 7A is a diagram showing the propagation path of the ultrasonic beam U in the conventional ultrasonic inspection method, and it is a diagram showing the time when it is incident on the healthy part N. FIG. FIG. 7B is a diagram showing the propagation path of the ultrasonic beam U in the conventional ultrasonic inspection method, and is a diagram showing the time when it is incident on the defect portion D. FIG. In the conventional ultrasonic inspection method, for example, as described in Patent Document 1, the sending probe 110 and the receiving probe 140 as the receiving probe 121 are arranged coaxially so that the sending sound axis AX1 and the receiving sound axis AX2 coincide.

As shown in FIG. 7A , when the ultrasonic beam U is incident on the healthy part N of the subject E, the ultrasonic beam U passes through the subject E and reaches the coaxially arranged receiving probe 140 . Therefore, the received signal becomes large. On the other hand, as shown in FIG. 7B , when the ultrasonic beam U is incident on the defect D, the defect D blocks the transmission of the ultrasonic beam U, so the received signal decreases. In this way, the defective portion D is detected by decreasing the received signal. This is shown in Patent Document 1.

Here, as shown in FIG. 7A and FIG. 7B , the method of detecting the defective part D by blocking the transmission of the ultrasonic beam U in the defective part D to reduce the received signal is referred to herein as the "blocking method". On the other hand, like this embodiment, the inspection method of detecting the scattered wave U1 of the defect part D is called "scattering method".

FIG. 8 is a graph showing the plotting of signal strength data from previous ultrasound inspection methods. This figure is a signal strength chart, and this signal strength chart is the ultrasonic inspection method of the inventors according to the blocking method shown in Figure 7A and Figure 7B, that is, to make the configuration of the sending sound axis AX1 consistent with the receiving sound axis AX2, What was obtained by inspecting the object E having the same defective portion D as the object E used in FIG. 5 above. In FIG. 8, the part of code|symbol D1 is a part corresponded to the defect part D. As shown in FIG.

In FIG. 8 , it was confirmed that the signal decreased at the center position of the defect portion D (position 0 mm), but the amount of decrease was small. This is considered to be caused by the fact that, in the defect portion D which is smaller than the size of the ultrasonic beam U, more ultrasonic beams U pass through its surroundings. Therefore, in the blocking method of making the transmission sound axis AX1 coincide with the reception sound axis AX2, it is difficult to detect a signal change originating from the defect part D, and the detection sensitivity is low.

In contrast, by offsetting the transmitting sound axis AX1 and the receiving sound axis AX2, it is possible to reduce the ultrasonic wave passing around the defect part D which is smaller than the size of the ultrasonic beam U in the strength of the signal received by the eccentrically arranged receiving probe 120 Beam U signal. Thereby, the amount of decrease in signal intensity caused by the defect part D can be relatively increased, and the detection performance of the defect part D can be improved, especially the detection sensitivity can be improved. Here, as also shown in FIG. 5 above, it can be seen that according to the configuration of the preferred scattering method in this embodiment, the position of the defect D can be clearly detected compared with the result of FIG. 8 using the blocking method. That is, comparing the reception result shown in FIG. 8 of the comparative example with the reception result of the method of this embodiment shown in FIG. 5, the method of this embodiment shown in FIG. 5 can obtain a high SN ratio.

Thus, the reason why a high SN ratio can be obtained by the scattering method of this embodiment will be described with reference to FIGS. 9A and 9B .

FIG. 9A is a diagram showing the interaction between the defect portion D in the subject E and the ultrasonic beam U, and is a diagram showing the reception of the direct ultrasonic beam U (hereinafter referred to as "direct wave U3"). The direct wave U3 will be described below. FIG. 9B is a diagram showing the interaction between the defect portion D in the subject E and the ultrasonic beam U, and is a diagram showing the state of receiving the scattered wave U1. Here, the case where the size of the defect portion D is smaller than the width of the ultrasonic beam U (hereinafter referred to as beam width BW) will be considered. The beam width BW here is the width of the ultrasonic beam U when it reaches the defect D.

9A and 9B schematically show the shape of the ultrasonic beam U in the micro region near the defect D, so the ultrasonic beam U is drawn in parallel, but it is actually a focused ultrasonic beam U. Furthermore, the position of the receiving probe 121 in FIG. 9A and FIG. 9B is described for ease of understanding, and the position and shape of the receiving probe 121 are not accurately scaled when the conceptual position is recorded. That is, considering the magnification of the shape of the defect portion D and the ultrasonic wave U, the receiving probe 121 is located farther from the position shown in FIGS. 9A and 9B in the vertical direction of the drawing. Here, the receiving probe 121 is the receiving probe 140 arranged coaxially in FIG. 9A , and means the receiving probe 120 arranged eccentrically in FIG. 9B .

Even if the ultrasonic beam U is focused and incident, it has a limited width in the vicinity of the defect D. Let this be the beam width BW at the position of the defect part D. Incidentally, in FIGS. 9A and 9B , a case where the beam width BW at the position of the defect D is wider than the size of the defect D is shown.

FIG. 9A is a diagram showing the situation of the blocking method for making the transmission sound axis AX1 coincide with the reception sound axis AX2. When the defect portion D is smaller than the beam width BW, since a part of the ultrasonic beam U is blocked, the received signal decreases, but it does not become zero. For example, when the cross-sectional area of the defect D is 20% of the beam cross-sectional area defined by the beam width BW, it is difficult to detect the defect D because the received signal is only reduced by about 20%. That is, in the case shown in FIG. 9A , the reduction of the received signal is limited to 20% at the location where the defective portion D exists (see FIG. 8 ).

Fig. 9B is a diagram showing the situation of the preferred method of this embodiment, that is, the situation of the scattering method. In the scattering method, when the ultrasonic beam U does not collide with the defect D, the ultrasonic beam U does not enter the eccentrically arranged receiving probe 120 , so the received signal is zero. Furthermore, as shown in FIG. 9B , when a part of the ultrasonic beam U collides with a defect D, the scattered wave U1 is observed at the receiving probe 120 arranged eccentrically, so it is easier to detect the defect D than the blocking method. That is, the reception signal is zero if the defect portion D does not exist, and the reception signal is not zero if the defect portion D exists, although it is small. Therefore, the SN ratio can be improved (see FIG. 5 ).

Thus, according to the method (scattering method) of this embodiment, the defect part D smaller than the beam width BW can be detected with high sensitivity. Here, "high-sensitivity detection is possible" means that a defect portion D smaller than the previous one can be detected. That is, the lower limit of the size of the detectable defect portion D is smaller than the previous one.

Also, as shown in FIG. 9A, in the blocking method, the defective portion D is determined based on the amount of received signal corresponding to the healthy portion N based on the amount of decrease therefrom. Therefore, it is preferable to set the received signal of the healthy part N to a fixed value. However, in the ultrasonic waves propagating in the fluid F, especially in the gas G, the intensity reaching the receiving probe 121 is extremely small compared with the ultrasonic waves propagating in the liquid W ( FIG. 17 ). Therefore, it is preferable to amplify the received signal with a high amplification ratio (gain). Therefore, to keep the gain constant, a high-precision signal amplifier circuit is the best. On the other hand, in the scattering method of this embodiment, as shown in FIG. 5, the signal in the healthy portion N is approximately zero, and the signal is observed in the defective portion D, so the requirement for gain stability of the signal amplifier circuit can be reduced. However, in the above-mentioned FIG. 5, the signal strength value is increased by the offset value.

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

FIG. 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 for generating a voltage applied to the transmission probe 110 . The transmission system 210 includes a waveform generator 211 and a signal amplifier 212 . The waveform generator 211 generates a burst wave signal. And, the burst signal to be generated is amplified by the signal amplifier 212 . The voltage output from the signal amplifier 212 is applied to the transmission probe 110 .

The receiving system 220 is a system that detects the received signal output from the off-center configured receiving probe 120 . The signal output from the eccentrically arranged receiving probe 120 is input to the signal amplifier 222 and amplified. The amplified signal is input to the waveform analysis unit 221 . The waveform analysis unit 221 generates signal strength data ( FIG. 5 ) from the received signal. Send the generated signal strength data to the data processing unit 201 .

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

The phase of the signal is the delay time from when the sending probe 110 emits the ultrasonic beam U to when it reaches the specific position of the receiving signal. The specific position of the received signal indicates the position of the characteristic received signal in the received signal where the delay time can be easily calculated. For example, when using burst waves of 10 waves, it is the position of the third wave.

Furthermore, as the phase of the signal, the delay time within the fundamental period of the signal can also be used. The fundamental period of the signal is the reciprocal of the fundamental frequency f0. For example, when using a burst wave with a basic frequency f0=800 kHz, the basic period is 1.25 μs. The phase extractor 231 calculates the specific position of the received signal, for example, where the zero-crossing point is located in the fundamental period. In this embodiment, the phase extracting unit 231 calculates the remainder of dividing the delay time by the basic period T0 of the signal, thereby calculating the phase within the basic period.

The data processing unit 201 includes a phase change calculation unit 232 . The phase variation calculation unit 232 receives phase information as an input signal, and also receives scanning position information from the scanning controller 204 . Using these two pieces of information, the phase change amount calculation unit 232 calculates the phase change amount (phase change amount per scan position) related to the scanning position of the phase information extracted by the phase extraction unit 231 . The amount of change corresponds to the spatial differential of the phase information of the signal relative to the scanning position.

"Phase variation related to the scanning position" includes not only the variation (spatial differential), but also signal quantities (variation) indicating the magnitude of the variation (spatial differential), such as its square value and absolute value. By scanning on the xy two-dimensional plane and calculating the amount of change in the two-dimensional scanning position (x, y), an image in which the contour of the defective portion D can be easily grasped can be obtained.

The method of calculating the amount of change in the phase information of the phase change amount calculating unit 232 includes, for example, computing processing using a CPU (Central Processing Unit: central processing unit) or a microcomputer (microcontroller), using an FPGA (Field-Programmable Gate Array: field programmable gate array), digital signal processing, analog circuit signal processing, etc.

In this way, the phase change of the signal is extracted at each scanning position in the x-axis direction and the y-axis direction by the phase extraction part 231 and the phase change amount calculation part 232, and the phase change amount related to the scanning position is calculated. The signal changes caused by different scanning positions are described below.

FIG. 11 is a diagram schematically showing the change of the received signal of the eccentrically arranged receiving probe 120 at each scanning position in the x-axis direction. The dotted line in the vertical direction is the position where the defective portion D exists, and the width of the defective portion D is WD. For reference, the signal amplitude when the coaxial arrangement receiving probe 140 based on the transmission method is set is shown in graph G1. Graph G2 shows the signal amplitude of the signal received by the eccentrically arranged receiving probe 120 , and is the output signal of the waveform analysis unit 221 . It can be seen that in either of the graphs G1 and G2, the signal amplitude becomes large in the vicinity of the defect part D, and the defect part D can be detected.

However, in either graph G1, G2, the width|variety of a signal is wider than WD which is the dimension (width) of the defect part D. The reason for this is that the beam size of the ultrasonic beam U is relatively large. That is, when part of the ultrasonic beam U is irradiated to the defect part D, the scattered wave U1 is also generated, so the signal amplitude of the scattered wave U1 gradually increases near the defect part D. Therefore, the amplitude of the signal is wider than the size of the actual defect D. When it is displayed on the display device 3 , the size of the defect portion D appears to be larger than the actual size, corresponding to a state where the resolution is lowered. Therefore, based only on the graphs G1 and G2, the resolution of the image displaying the outline of the defective portion D displayed on the display device 3 may decrease.

Graph G3 plots the phase of the signal of the scattered wave U1, and is the 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 part D (FIG. 6B). The reason for this will be described below with reference to FIGS. 12A to 12C . Graph G4 plots the phase change of the phase signal of the scattered wave U1 relative to the scanning position in the x-axis direction, and is the output signal of the phase change calculation unit 232 ( FIG. 10 ). Graph G4 corresponds to the signal obtained by spatially differentiating the phase signal of the scattered wave U1 with respect to the scanning position in the x-axis direction. Furthermore, graph G5 is drawn by squaring the value of graph G4. Based on graphs G4 and G5, it can be seen that a signal corresponding to the contour of the defect portion D can be obtained, that is, a high-resolution image showing the contour of the defect portion D can be obtained. Therefore, by comparing graph G2 with graphs G3 to G5, it can be seen that the defect portion D can be detected with high resolution by calculating the phase change amount of the phase of the signal of the scattered wave U1 related to the scanning position.

FIG. 12A is a diagram showing the scanning position where the ultrasonic beam U is not incident on the defect portion D. FIG. FIG. 12B is a diagram showing the scanning position where the ultrasonic beam U is incident on the defect D, but the transmitting sound axis AX1 does not enter the defect D. FIG. FIG. 12C is a diagram showing the scanning position where the ultrasonic beam U is incident on the defect part D and the sending sound axis AX1 enters the defect part D. FIG. According to the study of the present inventors, the reason why the phase of the scattered wave U1 changes sharply at the position of the defect portion D is presumed to be as follows.

When scanning the scanning position (x1) where the ultrasonic beam U is not incident on the defect D (FIG. 12A), since no scattered wave U1 is generated, the signal amplitudes shown in graphs G1 and G2 of FIG. 11 above do not change. However, when the ultrasonic beam U is incident on the defect part D, but the transmission sound axis AX1 does not enter the scanning position (x2) of the defect part D during scanning (Fig. 12B), even if a part of the ultrasonic beam U is incident on the defect part D, the A scattered wave U1 is generated. Therefore, as shown in the graphs G1, G2 of FIG. 11 above, changes are seen in the signal amplitude. However, as shown in graphs G3 to G5 of FIG. 11 above, the phase does not change. This is considered to be caused by the eccentric arrangement of the receiving probe 120 to receive the received components including the scattered wave U1 and the ultrasonic beam U from various directions, which are mixed, and it is difficult to confirm the phase change as a result.

As shown in FIG. 12C , when the ultrasonic beam U is incident on the defect D and the transmission sound axis AX1 enters the scanning position (x3) of the defect D, the phase changes significantly as shown in graphs G3 to G5 of FIG. 11 above. This is considered to be because the ultrasonic beam U enters the defect D in a state suitable for scattering by the defect D when the transmission sound axis AX1 of the ultrasonic beam U enters the defect D. Therefore, it is considered that this is because the off-centre receiving probe 120 receives most of the received component including the scattered wave U1, and a significant phase change occurs.

In this way, when the transmitting sound axis AX1 of the ultrasonic beam U irradiates the defect D, that is, when most of the received component of the eccentrically arranged receiving probe 120 is the scattered wave U1, the phase change of the scattered wave U1 can be clearly captured. Therefore, the position of the defect part D can be grasped by the phase change based on the scattered wave U1.

Returning to FIG. 10 , the data processing unit 201 images the information related to the defective portion D of the object E to be inspected, or detects the presence or absence of the defective portion D, and processes the acquired information into a desired form. In addition, images and information generated by the data processing unit 201 are displayed on the display unit 3 .

The scan controller 204 drives and controls the sending probe scanning unit 103 and the receiving probe 104 shown in FIG. 1 . Driving control of the sending probe scanning unit 103 and the receiving probe 104 is performed by the driving unit 202 . In addition, the scan controller 204 measures the position information of the sending probe 110 and the eccentrically arranged receiving probe 120 (the scanning positions in the x-axis direction and the y-axis direction; xy coordinates) via the position measuring unit 203 .

Based on the position information of the transmitting probe 110 and the eccentrically disposed receiving probe 120 received from the scanning controller 204 , the data processing unit 201 plots the signal strength data of each position, makes it into an image, and displays it on the display device 3 . As mentioned above, the signal strength data acquired in the defective portion D is greater than the signal strength data of the healthy portion N. Therefore, if the signal intensity data is plotted for the scanning position of the transmitting probe 110, an image showing where the defective portion D exists can be obtained. The display device 3 displays the image.

The data processing unit 201 generates an image by plotting the output signal from the phase change calculation unit 232 and the scanning position of the transmission probe 110 , and displays it on the display device 3 . As will be described later, the output signal from the phase change calculation unit 232 is given an image corresponding to the contour image of the defect portion D. As shown in FIG.

Two images of the image generated by the signal strength data and the image output by the phase change calculation unit 232 may be superimposed and displayed as one image. A superimposed image is an image displayed by superimposing a second image on top of a first image. At this time, the first image and the second image are superimposed so that the scanning positions of the two images correspond. For example, the image of the signal strength data can be displayed in a black and white image with grayscale, and the image output from the phase change calculation unit 232 can be superimposed and displayed in other colors such as yellow.

FIG. 13 is a diagram showing the hardware configuration of the control device 2 . The control device 2 is configured to include a memory 251 such as a RAM (Random Access Memory), a CPU (Central Processing Unit) 252, a ROM (Read Only Memory), and a HDD (Hard Disk Drive: hard drive). memory device 253 such as a disk drive), a communication device 254 such as a NIC (Network Interface Card), an I/F (Interface: Interface) 255 , and the like.

The control device 2 loads the specific control program stored in the memory device 253 into the memory 251 to be executed by the CPU 252 . Thereby, the data processing unit 201 , the position measurement unit 203 , the scan controller 204 , the phase acquisition unit 231 , the phase variation calculation unit 232 and the like in FIG. 3 are embodied.

Fig. 14 is a flow chart showing the ultrasonic inspection method of the first embodiment. The ultrasonic inspection method of the first embodiment can be executed by the above-mentioned ultrasonic inspection apparatus Z, and will be described with reference to FIGS. 1 and 10 as appropriate. The ultrasonic inspection method of the first embodiment inspects the object E by injecting the ultrasonic beam U on the object E ( FIG. 1 ) through the intervening gas G ( FIG. 1 ). In addition, the ultrasonic inspection method is described for the embodiment using the gas G as the fluid F, but of course this ultrasonic inspection method is also effective for the embodiment using the liquid W ( FIG. 17 ) as the fluid F.

First, according to the instruction of the control device 2 (FIG. 10), the emitting step S101 of emitting the ultrasonic beam U (FIG. 6B) from the transmitting probe 110 (FIG. 1) is performed. Next, in the eccentric arrangement of the receiving probe 120 ( FIG. 1 ), the receiving step S102 of receiving the ultrasonic beam U (scattered wave U1 in this example) is performed.

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

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

The scanning position information of the sending probe 110 and the eccentrically arranged receiving probe 120 is sent from the position measurement unit 203 ( FIG. 10 ) to the scanning controller 204 ( FIG. 10 ). The data processing unit 201 ( FIG. 10 ) plots the phase variation of each scanning position on the scanning position information of the transmitting probe 110 obtained from the scanning controller 204 . In this way, for example, the graphs G3 to G5 shown in FIG. 11 above can be obtained, and the amount of phase change can be visualized.

In addition, the above-mentioned Fig. 11 shows the case where 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 defect part is displayed in a two-dimensional image The contour information of D is displayed on the display device 3 .

After the phase change amount calculation step S104, the shape display step S105 is performed. In the shape display step S105, the shape of the defect portion D of the object E is displayed on, for example, the display device 3. On the display device 3, for example, an image depicting a scanning position exceeding a threshold value is displayed. In this way, since the effect of being able to clearly display the outline of the defect part D can be acquired, it is more preferable. The shape display step S105 is performed by the data processing unit 201 .

The data processing unit 201 determines whether the scanning is completed (step S111). When scanning is completed (Yes), the control device 2 ends the processing. When scanning is not completed (No (No)), the data processing unit 201 outputs instructions to the drive unit 202 ( FIG. 10 ) to move the sending probe 110 and the eccentrically arranged receiving probe 120 to the next scanning position (step S112), and return the process to the releasing step S101.

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

In addition, the fluid F may be a gas G (FIG. 1) as described above, or a liquid W (FIG. 17) as described later. However, in the case of using gas G such as air as the fluid F, a better effect is imparted for the following reasons.

Compared with liquid W, the attenuation of ultrasonic waves in gas G is larger. It is known that the attenuation of ultrasonic waves in gas G is proportional to the square of the frequency. Therefore, the upper limit of ultrasonic waves propagating in gas G is about 1 MHz. In the case of liquid W, ultrasonic waves from 5 MHz to several 10 MHz are propagated, so the usable frequency in gas G is lower than that in liquid W.

Generally, as the frequency of ultrasonic waves becomes lower, it becomes difficult to focus the ultrasonic beam U. Therefore, compared with the ultrasonic beam U in the liquid W, the 1 MHz ultrasonic beam propagating in the gas G has a larger beam diameter that can be focused. Therefore, when the gas G is used as the fluid F, the resolution of the amplitude image detected by the coaxial wiring receiving probe 140 ( FIG. 2A ) may decrease.

However, according to the present disclosure, when gas G is used as fluid F, it is also possible to obtain that the phase change (spatial differential) of the scattered wave U1 detected by the eccentrically arranged receiving probe 120 related to the scanning position is close to the defect part D The image of the contour image. Therefore, high resolution is also obtained in the case of using the gas G, not to mention the case of using the liquid W as the fluid F. In this way, when the gas G is used as the fluid F, the effect of the present disclosure is higher.

(second embodiment) Fig. 15 is a diagram schematically showing the configuration of an ultrasonic inspection device Z according to the second embodiment. In the second embodiment, the scanning measurement device 1 includes the receiving probe 140 arranged coaxially in addition to the receiving probe 120 arranged eccentrically. Here, the coaxially arranged receiving probe 140 is the receiving probe 121 arranged at a position where the eccentric distance L is zero. That is, the receiving sound axis AX2 of the receiving probe 140 arranged coaxially is the same as the sending sound axis AX1 of the sending probe 110 .

Fig. 16 is a diagram showing the configuration of the control device 2 of the second embodiment. The output signal of the eccentrically arranged receiving probe 120 is input to the receiving system 220a, and the phase information is extracted by the phase extracting part 231 therein. The phase information is input to the data processing unit 201, and the phase change calculation unit 232 therein calculates the phase change of the signal phase relative to the scanning position. This amount of phase change corresponds to the contour of the defective portion D as described above. In the phase change calculation unit 232, contour image data is generated.

The output signal of the coaxial receiving probe 140 is input to the receiving system 220 b, and after being amplified by the signal amplifier 223 , the amplitude information of the signal is extracted by the waveform analysis unit 221 . Since the receiving sound axis AX2 of the coaxially arranged receiving probe 140 is set in a manner consistent with the sending sound axis AX1 of the sending probe 110, the transmission amount of the ultrasonic beam U in the defect part D is blocked, so the coaxially arranged receiving probe 140 The amplitude of the received signal decreases in the defective portion D. This is the prior art defect detection method known as "Barrier Mode". The output signal of the waveform analysis part 221 of the receiving system 220b connected with the coaxial receiving probe 140 is input to the data processing part 201, and the amplitude image generating part 224 therein generates amplitude image data.

According to the above sequence, the signals from the receiving probe 120 in the eccentric arrangement generate profile image data, and the signals from the coaxial receiving probe 140 generate amplitude image data. These two image data are input to the image synthesis unit 225 of the data processing unit 201 . The image synthesis unit 225 synthesizes (superimposes) amplitude image data (first image) and contour image data (second image). As mentioned above, the amplitude image data is generated by the amplitude image generation unit 224 based on the amplitude of the direct wave U3 ( FIG. 9A ) received by the receiving probe 140 arranged coaxially, and shows the position of the defect part D inside the object E. By. The contour image data is generated by the phase change calculation unit 232 based on the phase change related to the scanning position and shows the contour of the defect part D inside the object E to be inspected. The synthesized image is input to the display device 3 and displayed.

When a defect D smaller than the focal size of the ultrasonic beam U is observed, the amplitude image data becomes an image with a blurred outline, but the contour image data gives a clear shape closer to the actual size of the defect D. Therefore, according to the second embodiment, there is an effect that the defect portion D can be imaged with higher resolution.

In addition, in the second embodiment, the information (contour image data) from the phase change amount calculation unit 232 obtained by synthesizing the signal received by the receiving probe 120 freely arranged eccentrically, and the signal received by the receiving probe 140 freely arranged The information (amplitude image data) obtained from the amplitude image generating unit 224 is superimposed and displayed on the display device 3 . However, in this disclosure, the utilization method of these two pieces of information, that is, the information of the phase change amount and the amplitude, is not limited to synthesizing two images.

Another embodiment of the method of utilizing these two pieces of information will be described below. In the following embodiments, a high-resolution display can be generated and displayed by appropriately combining the phase change obtained by the signal received by the freely eccentrically arranged receiving probe 120 and the amplitude obtained by the signal received by the freely coaxially arranged receiving probe 140 The image of the defective part D.

As a first example of the method of combining these two signals, at the scanning position where the output signal of the phase change calculation unit 232 exceeds a predetermined threshold value, the output signal from the waveform analysis unit 221 of the receiving probe 140 coaxially arranged, that is, the amplitude When the amount of change in the signal exceeds a predetermined threshold, it can be determined that there is a defective 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. Thereby, when calculating the spatial change amount of the phase change, that is, the phase change amount, even when a signal change occurs due to inadvertent noise mixing or the like, it is possible to suppress the occurrence of erroneous detection of the defective portion D.

In the second example, the output signal of the phase change calculation unit 232 can be used as the contour information of the defect part D, and the amplitude value of the received signal of the coaxially arranged receiving probe 140 can be used to determine which area in the image divided by the contour line Corresponds to the position of defect D. Based on this determination, a defect image is displayed on the display device 3 . Thereby, the defect part D can be displayed with good resolution.

(third embodiment) Fig. 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 the liquid W, which is water in the illustrated example. The ultrasonic inspection apparatus Z inspects the object E by injecting the ultrasonic beam U on the object E through the fluid F, that is, the liquid W. The test object E is placed below the liquid level L0 of the liquid W and 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 measurement device 1 is for scanning and measuring an object E with an ultrasonic beam U, and includes a sample table 102 fixed to a casing 101 , and the object E is placed on the sample table 102 . The object E to be inspected is made of any material. The test object E is, for example, a solid material, and more specifically, is, for example, metal, glass, resin material, or the like. In addition, the object E has a defective part D inside. The defective portion D is a cavity or the like. Examples of the defective portion D are cavities, foreign materials different from the original materials, and the like. In the object E, the part other than the defective part D is called a healthy part N.

Since the constituent materials of the defective part D and the healthy part N are different, the acoustic impedance is different between the two, and the propagation characteristics of the ultrasonic beam change. In the ultrasonic inspection apparatus Z, this change is observed, and the defect part D is detected.

The scanning measurement device 1 has a sending probe 110 emitting an ultrasonic beam U, and a receiving probe 120 arranged eccentrically. The transmitting probe 110 is installed in the casing 101 via the transmitting probe scanning unit 103 , and emits the ultrasonic beam U. The receiving probe 120 arranged eccentrically is the receiving probe 121 that is installed on the opposite side of the transmitting probe 110 relative to the object E to receive the ultrasonic beam U. The eccentric arrangement of the receiving probe 120 has a receiving sound axis AX2 at a position different from the sending sound axis AX1 of the sending probe 110 . The distance between the sending sound axis AX1 and the receiving sound axis AX2 is the eccentric distance L. The receiving probe 120 arranged eccentrically is provided in the casing 101 via the receiving probe scanning unit 104 .

In addition, when a liquid W such as water is used as the fluid F, among the receiving probes 121 ( FIG. 18 ) for receiving ultrasonic waves, those arranged at positions where the eccentric distance L is equal to or greater than zero are defined as eccentrically arranged receiving probes 120 , The receiving probe 140 arranged at a position where the eccentric distance L is zero is defined as a coaxially arranged receiving probe 140 ( FIG. 18 ). In other words, the receiving probe 121 includes the terms of the eccentrically arranged receiving probe 120 and the coaxially arranged receiving probe 140 .

In the third embodiment, the receiving probe 120 is arranged eccentrically with respect to the transmitting probe 110 offset by the eccentric distance L in the x-axis direction of FIG. Probe 120. Alternatively, it is also possible to arrange the eccentricity by shifting L1 in the x-axis direction and shifting L2 in the y-axis direction (that is, if the position of the transmitting probe 110 on the xy plane is taken as the origin, then the position is (L1, L2)). Receive probe 120 is configured.

In the third embodiment, as a preferred example, the receiving probe 120 is arranged eccentrically to receive the scattered wave U1 generated by the scattering of the ultrasonic beam U at the defect part D (FIG. 6B). Since the scattered wave U1 is generated due to the existence of the defect part D, the detection accuracy of the defect part D can be further improved by detecting the scattered wave U1. In the following example, for the sake of simplification, the present embodiment will be described by taking the eccentrically arranged receiving probe 120 disposed at a position capable of receiving the scattered wave U1 as an example.

The eccentric distance L is set as the position where the signal intensity of the defective part D is greater than the received signal of the healthy part N of the object E under inspection. This point is the same as that of the first embodiment.

The control device 2 provided in the ultrasonic inspection apparatus Z of the third embodiment will be described with further reference to the above-mentioned FIG. 10 . In the third embodiment, the control device 2 also 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 configuration and operation of the control device 2 are the same as those of the first embodiment.

The receiving system 220 includes a phase acquisition unit 231 . The output signal of the signal amplifier 222 is input to the phase extraction unit 231 . In the phase extracting unit 231, the above-mentioned phase information is generated from the received signal. Send the generated phase information to the data processing unit 201 .

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

Similar to the first embodiment, the amount of phase change due to the change in the scanning position corresponds to the contour information of the defect portion D. FIG. Therefore, by imaging the amount of phase change corresponding to the scanning position, a high-resolution image of the defect portion can be obtained.

(fourth embodiment) Fig. 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 the receiving probe 140 arranged coaxially in addition to the receiving probe 120 arranged eccentrically. Here, the coaxially arranged receiving probe 140 is the receiving probe 121 arranged at a position where the eccentric distance L is zero. That is, the receiving sound axis AX2 of the receiving probe 140 arranged coaxially is the same as the sending sound axis AX1 of the sending probe 110 .

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

In the fourth embodiment, similar to the above-mentioned second embodiment, the contour image data (second image) is synthesized from the amplitude image data (first image) based on the For the signal received by the receiving probe 140 in the coaxial arrangement, the above-mentioned synthetic contour image data (second image) is based on the signal received by the receiving probe 120 in the off-center arrangement, and based on the phase change related to the change of the scanning position By. The 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 according to a fifth embodiment. In the fifth embodiment, a transmitting and receiving probe 119 is provided instead of the transmitting probe 110 of the ultrasonic inspection apparatus Z ( FIG. 17 ) of the third embodiment. The transmitting and receiving probe 119 is in charge of the function of the coaxial arrangement receiving probe 140 ( FIG. 18 ) of the fourth embodiment and the function of the transmitting probe 110 ( FIG. 17 ) of the third embodiment. Therefore, the transmitting and receiving probe 119 emits the ultrasonic beam U and receives reflected waves from the object E (including the defect portion D).

Fig. 20 is a functional block diagram of an ultrasonic inspection device Z according to the fifth embodiment. The transmitting and receiving probe 119 emits an ultrasonic beam U by being applied with an excitation pulse output from the transmitting system 210 of the control device 2 . Thereafter, the connection end of the transceiver probe 119 is immediately switched to the receiving system 220 b of the control device 2 . Typically, switching is performed using a switch 235 within the control device 2 . In the fifth embodiment, for example, the switch 235 is a relay element or a semiconductor analog switch.

The ultrasonic beam U (reflected wave) reflected in the defect portion D is detected by the transmitting and receiving probe 119 . In the transmitting and receiving probe 119 , the sound wave of the reflected wave is converted into an electrical signal, which is input to the receiving system 220 b through the switch 235 . The waveform analysis unit 221 in the receiving system 220b extracts the amplitude signal of the reflected wave signal, and the amplitude image generation unit 224 generates amplitude image data (first image) based on the amplitude of the direct wave received by the transceiver probe 119 .

On the other hand, the signal detected by the eccentrically arranged receiving probe 120 is input to the receiving system 220 a, and the phase information of the signal is extracted in the phase extracting part 231 . The phase change amount related to the scanning position of the phase information is calculated by the phase change amount calculation unit 232 to generate contour image data (second image). The image synthesis unit 225 synthesizes and superimposes the amplitude image data and the contour image data, and outputs it to the display device 3 . In this way, the display device 3 superimposes and displays the two combined images.

As described above, the shape of the defect portion D can be detected with better resolution by the amount of phase change related to the scanning position based on the phase of the scattered wave signal. Therefore, the defective portion D can be imaged with higher resolution. In addition, since the transmitting and receiving probe 119 has both the functions of the transmitting probe 110 ( FIG. 17 ) and the coaxially arranged receiving probe 140 ( FIG. 18 ), the configuration of the scanning measurement device 1 can be simplified.

In addition, the ultrasonic inspection apparatus Z of the fifth embodiment can be realized by shifting the position of the coaxially arranged receiving probe 140 of the conventional ultrasonic inspection apparatus of the blocking method by the eccentric distance L. That is, the ultrasonic inspection equipment 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 arranged receiving probe 120 of the ultrasonic inspection apparatus Z according to the sixth embodiment. In the sixth embodiment, the relationship between the beam focusing properties of the transmitting probe 110 and the eccentrically arranged receiving probe 120 will be described.

In the sixth embodiment, the bundling property of the receiving probe 120 arranged eccentrically is looser than that of the transmitting probe 110 . The propagation path of the scattered wave U1 slightly changes according to the depth of the defect portion D inside the object E, the shape of the defect portion D, the inclination, and the like. Therefore, in the second embodiment, even if the path of the scattered wave U1 is changed, the eccentrically arranged receiving probe 120 can detect the scattered wave U1, thereby relaxing the bunching property of the eccentrically arranged receiving probe 120 .

The size relationship of the beam concentration is defined by the size relationship of the beam incident areas T1 and T2 on the surface of the object E to be inspected. The beam incidence areas T1 and T2 will be described.

FIG. 22 is a graph illustrating the relationship between the beam incident area T1 of the transmitting probe 110 and the beam incident area T2 of the eccentrically arranged receiving probe 120 . The beam incident area T1 of the sending probe 110 is the intersection area of the ultrasonic beam U emitted from the sending probe 110 on the surface of the object E to be inspected. In addition, the beam incident area T2 of the eccentrically arranged receiving probe 120 is the intersection area between the virtual ultrasonic beam U2 and the surface of the object E when the ultrasonic beam U is emitted from the eccentrically arranged receiving probe 120 .

In addition, in FIG. 22 , the path of the ultrasonic beam U is shown as the path when the subject E is not present. When the object E exists, the ultrasonic beam U propagates along a path different from the path indicated by the dotted line because the ultrasonic beam U is refracted on the surface of the object E. Here, as shown in FIG. 22 , the beam incident area T2 of the subject E where the receiving probe 120 is arranged eccentrically is larger than the beam incident area T1 of the subject E of the transmitting probe 110 . Thereby, the bundling property of the eccentrically arranged receiving probe 120 can be loosened compared with the bundling property of the transmitting probe 110 .

Furthermore, the focal length R2 of the receiving probe 120 arranged off-center is longer than the focal length R1 of the transmitting probe 110 . In this way, the bundling property of the eccentrically arranged receiving probe 120 can also be loosened compared with the bundling property of the transmitting probe 110 . At this time, the distances from the object E to the transmitting probe 110 and the eccentrically arranged receiving probe 120 are, for example, the same, but may be different.

Thus, in the sixth embodiment, the bundling properties of the receiving probes 120 arranged eccentrically are looser than the bundling properties of the transmitting probes 110 . That is, the focal length R2 of the eccentrically arranged receiving probe 120 is set to be 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 becomes wider, it is possible to inspect the scattered wave U1 in a wide range. Thereby, 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 receiving probe 120 arranged eccentrically exists on the side of the transmitting probe 110 (upper in the illustrated example) than the focal point of the transmitting probe 110 . Thus, by shifting the focal point, the scattered wave U1 can be easily received by the receiving probe 120 arranged eccentrically, and the scattered wave U1 can be easily detected.

In addition, the non-bundling type probe used in the first embodiment may also be used as the eccentrically arranged receiving probe 120 . Since the focal length R2 of the non-bundling probe is infinite, it is longer than the focal length R1 of the sending probe 110 . That is, even if the non-bundling type eccentrically arranged receiving probes 120 are used, the bundling properties of the eccentrically arranged receiving probes 120 are looser than those of the transmitting probes 110 .

(seventh embodiment) Fig. 23 is a diagram showing an example of an eccentric arrangement of the receiving probe 120 according to the seventh embodiment. And it is a top view of the transmitting probe 110 and the eccentrically arranged receiving probe 120 of the ultrasonic inspection device Z viewed from the negative side of the z-axis. That is, FIG. 23 is a view viewed from the eccentrically arranged receiving probe 120 side. In the third embodiment, the length b of the vibrator 111 ( FIG. 3 ) of the eccentrically arranged receiving probe 120 in the eccentric direction of the receiving sound axis AX2 relative to the sending sound axis AX1 is larger than the direction along the surface of the object E and the eccentricity. The length a of the direction perpendicular to the direction is long. The lengths a and b are characteristic lengths, which respectively refer to the length of the side of the rectangle for a rectangular vibrator, and refer to the major axis or minor axis of an ellipse for an elliptical vibrator.

If the aspect ratio of the eccentrically arranged receiving probe 120 is set in this way, the scattered wave U1 can be detected by the eccentrically arranged receiving probe 120 even if the depth of the defect D changes and the arrival position of the scattered wave U1 changes.

The scattered wave U1 is scattered in a radiation direction around the transmission sound axis AX1. Therefore, when the receiving probe 120 is arranged eccentrically at the position shown in FIG. 23 , the scattered wave U1 is scattered in the longitudinal direction of the receiving probe 120 arranged eccentrically (extending direction of "length b"). In other words, the extension direction of the "length b" is the direction in which the scattered wave U1 is emitted. Therefore, by increasing the value of the "length b", the scattered wave U1 scattered by the defect part D can be detected at various depths and the like. That is, even if the depth of the defect portion D changes and the arrival position of the scattered wave U1 changes, the scattered wave U1 can be detected by the eccentrically arranged receiving probe 120 .

The lengths a and b are not limited, as long as the length b is longer than the length a, that is, 1<b/a.

In addition, in FIG. 23 , the eccentric arrangement receiving probe 120 of a cuboid (rectangular shape) is shown, as the eccentric arrangement receiving probe 120, but it is set as an ellipse, and the major axis ratio and the minor axis ratio are set in the same way, and the same can be obtained. Effect.

(eighth embodiment) Fig. 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 adjustment unit 106 for adjusting the slope of the eccentrically arranged receiving probe 120 . Thereby, the strength of the received signal can be increased, and the signal-to-noise ratio (Signal to Noise ratio) of the signal can be increased. The installation angle adjustment unit 106 is, for example, not shown, and is composed of an actuator, a motor, and the like.

Here, the angle θ formed by the transmitting sound axis AX1 and the receiving sound axis AX2 is defined as the setting angle of the receiving probe. In the case of Figure 24, since the sending probe 110 is set in the vertical direction, the sending sound axis AX1 is in the vertical direction, so the setting angle of the receiving probe, that is, the angle θ, is the sending sound axis AX1 (that is, the vertical direction) and the eccentric arrangement of the receiving probe 120 is the angle formed by the normal of the probe face. And, by providing the angle adjustment unit 106, the angle θ is inclined toward 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 arranged obliquely. Specifically, the eccentric arrangement of the receiving probe 120 is inclined and arranged in a manner satisfying 0°<θ<90°, and the angle θ is, for example, 10°, but it is not limited thereto.

Also, the eccentric distance L when the eccentrically arranged receiving probe 120 is arranged obliquely is defined as follows. Define the intersection point C2 of the receiving sound axis AX2 and the probe surface of the eccentrically arranged receiving probe 120 . Furthermore, the intersection point C1 of the transmission sound axis AX1 and the probe surface of the transmission probe 110 is defined. The distance between the coordinate position (x4, y4) projected on the xy plane from the position of intersection C1 and the coordinate position (x5, y5) projected on the xy plane from the position of intersection C2 is defined as the eccentric distance L.

By disposing the receiving probe 120 obliquely and eccentrically in this way, when the present inventors actually detect the defect D, the signal strength of the received signal increases three times compared with the case of θ=0.

Fig. 25 is a diagram illustrating the cause of the effect of the eighth embodiment. The scattered wave U1 propagates in a direction deviated from the transmitting sound axis AX1. Therefore, as shown in FIG. 25 , when the scattered wave U1 reaches the outside of the subject E, it enters the interface between the subject E and the outside at an angle α2 with a non-zero normal vector to the surface of the subject E. Moreover, the angle of the scattered wave U1 emitted from the surface of the object E to be inspected has a non-zero outgoing angle relative to the normal direction of the surface of the object E to be inspected, that is, the angle β2. When the normal vector of the probe surface of the eccentrically arranged receiving probe 120 is aligned with the traveling direction of the scattered wave U1, the scattered wave U1 can be received with optimum efficiency. That is, by arranging the receiving probe 120 obliquely and eccentrically, the strength of the received signal can be increased.

In addition, when the angle β2 of the ultrasonic beam U emitted from the subject E coincides with the angle θ formed by the transmitting sound axis AX1 and the receiving sound axis AX2, the receiving effect is the highest. However, when the angle β2 does not completely coincide with the angle θ, the effect of increasing the received signal can also be obtained, so as shown in FIG. 25 , the angle β2 and the angle θ may not completely coincide.

In addition, in the scanning measurement device 1 ( FIG. 24 ), an installation angle adjustment unit 106 is provided, and the eccentric arrangement receiving probe 120 is installed by the installation angle adjustment unit 106 . The setting angle of the receiving probe 120 arranged eccentrically can be adjusted by setting the angle adjusting part 106 . Since the path of the scattered wave U1 varies slightly depending on the material, thickness, etc. of the object E to be inspected, the optimal value of the installation angle of the eccentrically arranged receiving probe 120 also varies. Therefore, since the installation angle of the receiving probe can be adjusted by the installation angle adjustment unit 106, the installation angle of the eccentrically arranged receiving probe 120 can be appropriately adjusted according to the material and thickness of the object E to be inspected.

In addition, in the eighth embodiment, the eccentric arrangement of the receiving probe 120 is arranged in an inclined state with respect to the horizontal plane, but the transmitting probe 110 may be arranged in an inclined state. Alternatively, the transmitting probe 110 may be arranged in a state inclined to the horizontal plane, and the probe surface of the eccentrically arranged receiving probe 120 may be arranged in parallel with 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 an offset state. In addition, in order to obtain the effect of inclined arrangement described in this embodiment, the angle θ (inclination angle) is set within the range of 0°<θ<90°. On the other hand, in other embodiments of the present disclosure, θ=0° is of course also possible.

(ninth embodiment) Fig. 26 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a ninth embodiment. In the ninth embodiment, the eccentrically arranged receiving probes 120 include a plurality of unit probes 120a. In the illustrated example, there are three unit probes 120a. The unit probes 120a are respectively disposed at positions with different eccentric distances L (distance from the transmission sound axis AX1).

Depending on the depth, shape, slope, 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 ) at the time of scattering is generally the same. Therefore, the deeper the defect D is, the closer the scattered wave U1 reaches to the transmitting sound axis AX1, and the shallower the defect D is, the farther the scattered wave U1 reaches from the transmitting sound axis AX1. Therefore, by using a plurality of unit probes 120a, information on the defect portion D (the depth of the defect portion D, etc.) can be obtained using the information at which position the unit probe 120a receives.

As the plurality of unit probes 120a, an array-type probe 122 ( FIGS. 28 and 29 ) in which a plurality of acoustic elements 122a ( FIGS. 28 and 29 ) are housed in one case may also be used. In this case, the unit probes 120a in FIG. 26 correspond to the acoustic elements respectively, and they are housed in one casing. The sensory element is an element that converts ultrasonic waves into electrical signals. As the acoustic sensing element, in addition to the piezoelectric element, a capacitive acoustic sensing element (CMUT, Capacitive Micro-machined Ultrasonic Transducer) and the like may also be used.

Fig. 27 is a functional block diagram of an ultrasonic inspection device Z according to the ninth embodiment. A plurality of unit probes 120a are connected to corresponding receiving systems 220c, 220d, 220e. The configuration of each of the receiving systems 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 are not shown in FIG. 27 , but are provided with a signal amplifier 222 , a waveform analysis unit 221 , and a phase acquisition unit 231 as shown in FIG. 10 . The signal from each unit probe 120 a is amplified by the signal amplifier 222 and input to the waveform analysis unit 221 and the phase acquisition unit 231 . The waveform analysis unit 221 outputs the amplitude of the received signal (scattered wave U1 ), and the phase extraction unit 231 outputs phase information of the received signal (scattered wave U1 ). The outputs from each of the receiving systems 220c, 220d, and 220e are input to the defect information judging section 205 .

The defect information determination part 205 is equipped in the control device 2, and is based on the unit probe that receives the scattered wave U1 of the irradiated ultrasonic beam U due to the scattering of the defect part D of the object E, among the plurality of unit probes 120a The received signal at 120a determines information related to the defect D of the object E (the depth of the defect D, etc.). Specifically, the defect information determining unit 205 determines the receiving system 220 most suitable for observing the scattered wave U1 based on the amplitude information from the waveform analyzing unit 221 of each of the receiving systems 220c, 220d, and 220e. In the ninth embodiment, the defect information judging unit 205 selects the receiving system 220 with the largest amplitude. And, the phase information from the phase acquisition unit 231 of the selected receiving system 220 is output to the data processing unit 201 .

The defect information determination unit 205 determines information related to the defect part D based on the waveform analysis results of each of the receiving systems 220c, 220d, and 220e. The term "based on the received signal" refers to which unit probe 120a detects which level of the received signal (scattered wave U1). Thereby, the accuracy of the position 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 calculation unit 232 . The phase variation calculation unit 232 uses the scanning position information from the scanning controller 204 of the scanning probe to calculate the phase variation of the received signal related to the scanning position variation. As described above, the amount of phase change related to the change in the scanning position is given to an image corresponding to the contour information of the defect part D. FIG. This information is visualized and displayed on the display device 3 .

In addition, the defect information determination unit 205 can also be provided as a part of the data processing unit 201 .

(tenth embodiment) Fig. 28 is a diagram showing the arrangement of eccentrically arranged receiving probes 120 according to the tenth embodiment. In this example, it is a plan view of the sending probe 110 and the eccentrically arranged receiving probe 120 viewed from the negative side of the z-axis in FIG. 1 , that is, the eccentrically arranged 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 eccentrically arranged receiving probes 120 include a plurality of unit probes 120a that are rectangular in plan view, and the plurality of unit probes 120a are arranged radially around the transmission sound axis AX1. In the illustrated example, there are eight unit probes 120a.

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

(Eleventh Embodiment) Fig. 29 is a diagram showing the arrangement of the eccentrically arranged receiving probes 120 in the eleventh embodiment, and is a diagram in which the unit probes 120a are arranged obliquely. The plurality of unit probes 120a are arranged symmetrically with respect to the transmission sound axis AX1. Therefore, at least two unit probes 120a are arranged at positions with the same eccentric distance L. In the illustrated example, three unit probes 120 a are arranged symmetrically on both sides of the transmitting sound axis AX1 in a plan view including the transmitting sound axis AX1 . In addition, two unit probes 120a are arranged at each of three different eccentric distances L positions. In addition, the unit probes 120a are arranged obliquely as in the above-mentioned eighth embodiment (FIG. 25).

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

By arranging at least two unit probes 120a at positions with the same eccentric distance L, scattered waves U1 scattered in plural directions can be detected. Also, in a plan view including the transmitting sound axis AX1 (FIG. 29 and FIG. 30), at least two unit probes 120a are arranged on both sides of the transmitting sound axis AX1, so that the scattered wave U1 in a wide range can be received. Furthermore, the control device 2 may determine that the defect portion D is actually detected when the scattered waves U1 are detected by the unit probes 120a on both sides, and it is determined to be an error when only one of them detects the scattered waves U1. Thereby, the detection accuracy of the defect part D can be improved.

(12th embodiment) Fig. 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 arranged receiving probes 140 is shorter than the focal length R2 of the eccentrically arranged receiving probes 120 . Thus, the coaxially arranged receiving probe 140 has higher bundling performance than the eccentrically arranged receiving probe 120 .

By making the focal length R3 of the coaxially arranged receiving probe 140 shorter than the focal length R2 of the eccentrically arranged receiving probe 120, the coaxially arranged receiving probe 140 can efficiently receive the ultrasonic beam U emitted from the sending probe 110, and receive sound. Ultrasound beam U on axis AX2. On the other hand, since the scattered wave U1 has a plurality of propagation paths, the scattered wave U1 can be sufficiently received by reducing the beam concentration of the eccentrically arranged receiving probe 120 that receives it. Therefore, it is possible to detect defects more efficiently by using the receiving probe 121 having a beam focus matching the characteristics of each of the direct wave U3 and the scattered wave U1 .

(13th Embodiment) Fig. 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 eccentrically arranged receiving probe 120 and the coaxially arranged receiving probe 140 is used. The array probe 122 is a receiving probe 121 arranged in a single dimension ( FIG. 32 ) or a two-dimensional ( FIG. 33 ) arrangement of a plurality of acoustic elements 122 a (also functioning as a unit probe 120 a ( FIG. 26 ).

The array type probe 122 is arranged such that the receiving sound axis AX2 of one acoustic sensor 122a is aligned with the sending sound axis AX1. The acoustic sensor 122a arranged in this arrangement functions as the coaxial arrangement receiving probe 140 . Similar to the example shown in FIG. 26, the remaining acoustic elements 122a are continuously and symmetrically arranged in the left and right directions of the paper with the transmitting sound axis AX1 as the center in FIG. In this example, the acoustic elements 122a are arranged in one dimension.

By using the array-type probe 122, the sensor element 122a is arranged in one dimension, and the number of sensor elements 122a is reduced, so the installation cost of the array-type probe 122 can be reduced, and scattered waves can be received by a plurality of sensor elements 122a U1. In addition, when the defect D is small and completely prevents the ultrasonic wave from propagating, the acoustic element 122a having the receiving sound axis AX2 coincident with the sending sound axis AX1 can also detect the reduction of the signal amount. Thereby, the small defect part D to the large defect part D can be detected efficiently.

(14th Embodiment) Fig. 33 is a diagram showing the configuration of an ultrasonic inspection apparatus Z according to a fourteenth embodiment. FIG. 33 is a top view of the transmitting probe 110 and the array probe 122 viewed from the negative side of the z-axis in FIG. 1 , that is, the side of the array probe 122 . In FIG. 32 mentioned above, the acoustic elements 122a constituting the array type probe 122 are arranged one-dimensionally in only one direction. However, in the array type probe 122 shown in FIG. 33, the acoustic elements 122a are two-dimensionally arranged in two xy directions. In the illustrated example, the same number of sound sensing elements 122a are arranged in each xy direction (7 pieces each), and they are arranged in a square shape. However, the acoustic sensing element 122a is not limited to the arrangement of a square shape, and may also be arranged in various shapes such as a rectangle, a circle, and an ellipse.

By using the array type probe 122 and arranging the acoustic elements 122a two-dimensionally, more acoustic elements 122a can receive the scattered wave U1, and the missed detection of the scattered wave U1 can be suppressed. In addition, when the defect D is relatively large and completely prevents the propagation of ultrasonic waves, the acoustic element 122a having the receiving sound axis AX2 coincident with the sending sound axis AX1 can also detect the reduction of the signal amount. Thereby, the small defect part D - the large defect part D can be detected efficiently.

In each of the above embodiments, an example is described in which the defect portion D is a cavity, but the defect portion D may be foreign matter mixed in a material different from that of the object E to be inspected. In this case, since there is a difference in acoustic impedance (Gap) at the interface between different materials, scattered waves U1 are generated, so the configurations of the above-mentioned embodiments are effective. The ultrasonic inspection device Z of this embodiment is based on an ultrasonic defect imaging device, but it can also be applied to a non-contact in-line internal defect inspection device.

This indication is not limited to the said embodiment, Various modification examples are included. For example, the above-mentioned embodiments are described in detail for the sake of easy understanding of the present disclosure, and are not necessarily limited to those having all the configurations described. Also, a part of the configuration of a certain embodiment may be replaced with a configuration of another embodiment, or a configuration of another embodiment may be added to the configuration of a certain embodiment. In addition, other configurations may be added, deleted, or substituted for a part of the configuration of each embodiment.

In addition, each of the above-mentioned configurations, functions, and parts constituting the block diagram can also be realized by hardware by designing a part or all of them, for example, with an integrated circuit. In addition, as shown in FIG. 13, the above-mentioned configurations, functions, etc. can also be realized by software by making processors such as CPU 252 interpret and execute programs for realizing each function. Information such as programs, forms, and files that realize various functions can be stored in memory, SSD (Solid State Drive: Solid State Drive) and other recording devices, or IC (Integrated Circuit: Integrated Circuit) cards, in addition to HDD. SD (Secure Digital: Secure Digital) card, DVD (Digital Versatile Disc: Digital Versatile Disc) and other recording media.

In addition, in each embodiment, the display of the control line and the information line is considered necessary for explanation, and not all the control lines and information lines may be shown on the product. It can be considered that virtually all components are connected to each other.

1: Scanning measuring device 2: Control device 3: Display device 101: Shell 102: Sample table 103:Send probe scanning part 104: Receiving probe scanning part 105: Eccentric distance adjustment part 106: setting angle adjustment part 110:Send probe 111: vibrator 112: Backing 113: Integration layer 114: probe surface 115: Send probe housing 116: connector 117: Lead 118:lead 119: Send and receive probe 120: Eccentric configuration receiving probe 120a: unit probe 121: Receive probe 122: Array probe 122a: sensory element 140: coaxial configuration receiving probe 201: Data Processing Department 202: Drive Department 203: Position measurement department 204: scan controller 205: Defect Information Judgment Department 210: sending system 211: Waveform generator 212: signal amplifier 220: Receiving system 220a: receiving system 220b: receiving system 220c: receiving system 220d: receiving system 220e: receiving system 221:Waveform analysis department 222: signal amplifier 223: signal amplifier 224: Amplitude image generation part 225: Image synthesis department 231: Phase acquisition unit 232: Phase variation calculation unit 235: switch 251: memory 252:CPU 253: memory device 254: Communication device 255:I/F a: length AX1: send audio axis AX2: receiving audio axis b: length BW: beam width C1: Intersection C2: Intersection D: defect department D1: Cavity E: Subject to be inspected F: Fluid G: gas G1: Chart G2: Chart G3: Chart G4: Chart G5: Chart L: eccentric distance L0: liquid level N: healthy part R1: focal length R2: focal length R3: focal length S101: release step S102: receiving step S103: Phase acquisition step S104: Phase change calculation step S105: Shape display step S111: step S112: step T1: Beam incident area T2: Beam incident area U: Ultrasonic beam U1: scattered wave U2: Ultrasonic beam U3: Direct wave W: Liquid WD: width x1: scan position x2: scan position x3: scan position Z: Ultrasonic inspection device α: tilt angle α2: Angle β: angle of refraction β2: Angle θ: angle

Fig. 1 is a diagram showing the configuration of an ultrasonic inspection device according to a first embodiment. Fig. 2A is a diagram illustrating the sending sound axis, the receiving sound axis and the eccentric distance, and it is the case where the sending sound axis and the receiving sound axis extend in the vertical direction. Fig. 2B is a diagram illustrating the sending sound axis, the receiving sound axis and the eccentric distance, and it is the situation where the sending sound axis and the receiving sound axis extend obliquely. Fig. 3 is a schematic cross-sectional view showing the structure of the sending probe. FIG. 4A is a received waveform from an eccentrically arranged receiving probe, and is a diagram showing a received waveform of a healthy part N of an object E to be inspected. FIG. 4B is a reception waveform from an eccentrically arranged reception probe, and is a diagram showing a reception waveform of a defect portion D of the object E to be inspected. Fig. 5 is a graph showing an example of plotting signal strength data. Fig. 6A is the propagation path of the ultrasonic beam of the present embodiment, and is a diagram showing the situation of incident ultrasonic beams to healthy parts. Fig. 6B is a propagation path of an ultrasonic beam according to the present embodiment, and is a diagram showing a situation where an ultrasonic beam is incident on a defect portion. Fig. 7A is a diagram showing the propagation path of the ultrasonic beam in the previous ultrasonic inspection method, and it is a diagram showing the incident time to healthy parts. Fig. 7B is a diagram showing the propagation path of the ultrasonic beam in the conventional ultrasonic inspection method, and is a diagram showing the time when it is incident on a defect portion. FIG. 8 is a graph showing the plotting of signal strength data from previous ultrasound inspection methods. FIG. 9A is a diagram showing the interaction between a defect portion in the subject to be inspected and an ultrasonic beam, and is a diagram showing a situation in which a direct ultrasonic beam is received. FIG. 9B is a diagram showing the interaction between a defect portion in the subject and an ultrasonic beam, and is a diagram showing a state of receiving scattered waves. Fig. 10 is a functional block diagram of the control device. FIG. 11 is a diagram schematically showing changes in received signals of eccentrically arranged receiving probes at various scanning positions in the x-axis direction. FIG. 12A is a diagram showing a scanning position where an ultrasonic beam is not incident on a defect portion. Fig. 12B is a diagram showing the scanning position where the ultrasonic beam is incident on the defect, but the transmitting sound axis does not enter the defect. FIG. 12C is a diagram showing the scanning position where the ultrasonic beam is incident on the defect and the sending sound axis enters the defect. Fig. 13 is a diagram showing the hardware configuration of the control device. Fig. 14 is a flow chart showing the ultrasonic inspection method of the first embodiment. Fig. 15 is a diagram showing the configuration of an ultrasonic inspection device according to the second embodiment. Fig. 16 is a functional block diagram showing the ultrasonic inspection device of the second embodiment. Fig. 17 is a diagram showing the configuration of an ultrasonic inspection device according to a third embodiment. Fig. 18 is a diagram showing the configuration of an ultrasonic inspection device according to a fourth embodiment. Fig. 19 is a diagram showing the configuration of an ultrasonic inspection device according to a fifth embodiment. Fig. 20 is a functional block diagram showing the ultrasonic inspection device of the fifth embodiment. Fig. 21 is a diagram showing the relationship between the transmitting probe and the eccentrically arranged receiving probe of the ultrasonic inspection device according to the sixth embodiment. Fig. 22 is a graph illustrating the relationship between the beam incident area of the transmitting probe and the beam incident area of the eccentrically arranged receiving probe. Fig. 23 is a diagram showing an example of receiving probes arranged eccentrically in the seventh embodiment. Fig. 24 is a diagram showing the configuration of a scanning measurement device of an ultrasonic inspection device according to an eighth embodiment. Fig. 25 is a diagram illustrating the cause of the effects of the eighth embodiment. Fig. 26 is a diagram showing the configuration of an ultrasonic inspection device according to a ninth embodiment. Fig. 27 is a functional block diagram of an ultrasonic inspection device according to a ninth embodiment. Fig. 28 is a diagram showing the arrangement of eccentrically arranged receiving probes according to the tenth embodiment. Fig. 29 is a diagram showing the arrangement of eccentrically arranged receiving probes in the eleventh embodiment, and is a diagram in which unit probes are arranged obliquely. Fig. 30 is a diagram showing the arrangement of eccentrically arranged receiving probes according to the eleventh embodiment, and is a diagram in which unit probes are arranged in the vertical direction. Fig. 31 is a diagram showing the configuration of an ultrasonic inspection device according to a twelfth embodiment. Fig. 32 is a diagram showing the configuration of an ultrasonic inspection device according to a thirteenth embodiment. Fig. 33 is a diagram showing the configuration of an ultrasonic inspection device according to a fourteenth embodiment.

1: Scanning measuring device

2: Control device

3: Display device

110:Send probe

120: Eccentric configuration receiving probe

121: Receive probe

201: Data Processing Department

202: Drive Department

203: Position measurement department

204: scan controller

210: sending system

211: Waveform generator

212: signal amplifier

220: Receiving system

221:Waveform analysis department

222: signal amplifier

231: Phase acquisition unit

232: Phase variation calculation unit

Z: Ultrasonic inspection device

Claims (19)

An ultrasonic inspection device that inspects an object to be inspected by injecting an ultrasonic beam on the object through a fluid, and includes: a scanning measurement device that scans the object to be inspected with the ultrasonic beam and measurement; and a control device, which controls the driving of the above-mentioned scanning measurement device; the above-mentioned scanning measurement device has: a sending probe that emits the above-mentioned ultrasonic beam, and an eccentrically configured receiving probe that receives the ultrasonic beam, and the above-mentioned sending probe In the way that the eccentric distance between the sending sound axis and the receiving sound axis of the above-mentioned eccentrically arranged receiving probe is greater than zero, the above-mentioned eccentrically arranged receiving probe is arranged, and the above-mentioned sending probe and the above-mentioned eccentrically arranged receiving probe are arranged in the x-axis direction or the y-axis direction For scanning, the transmitting probe is arranged in such a way that the transmitting sound axis is perpendicular to the xy plane formed by the x-axis direction and the above-mentioned y-axis direction, and the above-mentioned control device has: a phase acquisition part, which captures the above-mentioned eccentrically arranged receiving probe. Phase information of the received signal of the ultrasonic beam; and a phase variation calculation unit, which calculates the phase variation related to the scanning position of the extracted phase information. Such as the ultrasonic inspection device of claim 1, wherein The eccentric distance is set as a distance capable of receiving scattered waves of the ultrasonic beam caused by scattering of the defect portion of the object under inspection. The ultrasonic inspection device according to claim 1 or 2, wherein the strength of the received signal received by the eccentric arrangement of the receiving probe when incident on the defective part of the above-mentioned inspected object is greater than that when it is incident on the healthy part of the inspected object In the way of strength, set the above-mentioned eccentric distance. The ultrasonic inspection device according to claim 1 or 2, wherein the above-mentioned eccentric distance is set as a distance at which no received signal other than noise is detected when the healthy part of the above-mentioned object under inspection is irradiated. The ultrasonic inspection device according to claim 1 or 2, which includes: an eccentric distance adjustment unit for adjusting the position of at least one of the sending probe or the eccentrically arranged receiving probe. The ultrasonic inspection device according to claim 1 or 2, wherein the focal length of the above-mentioned eccentrically arranged receiving probe is longer than the focal length of the above-mentioned sending probe. The ultrasonic inspection device according to claim 1 or 2, wherein the focal point of the eccentrically arranged receiving probe exists on a side closer to the sending probe than the focus of the sending probe. The ultrasonic inspection device according to claim 1 or 2, wherein the incident area of the beam of the eccentrically arranged receiving probe on the object to be inspected is larger than the area of incident beam of the transmitting probe on the object to be inspected. The ultrasonic inspection device according to claim 1 or 2, wherein the scanning measurement device is equipped with: an angle adjustment unit, which makes the angle θ formed by the transmitting sound axis and the receiving sound axis satisfy 0°<θ<90°, Adjust the slope of the above-mentioned eccentric configuration to receive the probe. The ultrasonic inspection device according to claim 1 or 2, wherein the eccentrically arranged receiving probes include a plurality of unit probes. The ultrasonic inspection device according to claim 10, wherein the control device includes a defect information determination unit, which receives the irradiated ultrasonic beam from the scattering of the defective part of the object to be inspected based on the plurality of unit probes. The received signal of the above-mentioned unit probe of the generated scattered wave is used to determine the information related to the defect portion of the above-mentioned inspected object. The ultrasonic inspection device according to claim 1 or 2, wherein the scanning measurement device has a coaxial receiving probe arranged at a position where the eccentric distance is zero. Such as the ultrasonic inspection device of claim 12, wherein The above-mentioned control device has an image synthesizing unit which synthesizes the following first image and second image. The first image is based on the amplitude of the direct wave received by the coaxially arranged receiving probe and displays the The position of the defect part inside the inspection object; the second image, which is generated by the above-mentioned phase change amount calculation part based on the phase change amount related to the scanning position and shows the outline of the defect part inside the above-mentioned object under inspection. The ultrasonic inspection device according to claim 1 or 2, wherein the transmitting probe is a transmitting and receiving probe that emits the ultrasonic beam and receives reflected waves from the object to be inspected. The ultrasonic inspection device according to claim 14, wherein the above-mentioned control device has an image synthesis unit, which synthesizes the following first image and second image, the first image is based on the image received by the above-mentioned sending and receiving probe The one generated by the amplitude of the direct wave showing the position of the defect inside the above-mentioned object under inspection; the second image, which is generated by the above-mentioned phase change amount calculation unit based on the phase change amount related to the scanning position and shows the inside of the above-mentioned object under inspection Outline of the defective part. The ultrasonic inspection device according to claim 1 or 2, wherein the above-mentioned fluid is gas. An ultrasonic inspection method, which performs the inspection of the object to be inspected by injecting an ultrasonic beam on the object to be inspected through a fluid, scanning the sending probe and the eccentrically arranged receiving probe in the x-axis direction or the y-axis direction, The transmitting probe is arranged in such a way that the transmitting sound axis of the transmitting probe is perpendicular to the xy plane formed by the above-mentioned x-axis direction and the above-mentioned y-axis direction, and includes: an emitting step, which emits an ultrasonic beam from the above-mentioned transmitting probe The receiving step is to receive the above-mentioned ultrasonic beam in the above-mentioned eccentric configuration receiving probe having a receiving sound axis at a position different from the above-mentioned sending sound axis; the phase extraction step is to extract the above-mentioned ultrasonic beam received by the above-mentioned eccentric configuration receiving probe. The phase information of the signal of the sound beam; and the step of calculating the phase change amount, calculating the phase change amount related to the scanning position of the extracted phase information. The ultrasonic inspection method according to Claim 17, which includes: a shape display step, which determines whether the above-mentioned phase change amount related to the above-mentioned scanning position of the above-mentioned phase information generated in the above-mentioned phase change amount calculation step is a preset threshold value Above, the shape of the defective part of the above-mentioned object to be inspected is shown. The ultrasonic inspection method according to claim 17 or 18, wherein the above-mentioned fluid is gas.

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