JP2022000609A - Ultrasonic inspection device and ultrasonic inspection method - Google Patents

Abstract

To provide an ultrasonic inspection device having excellent detection accuracy of a defective portion.SOLUTION: An ultrasonic inspection device Z that inspects a test object E by irradiating the test object E with an ultrasonic beam through a gas includes: a scanning measurement device 1 that scans the test object E with an ultrasonic beam and performs measurements; a control device 2 that controls a drive of the scanning measurement device 1; and a display device 3. The scanning measurement device 1 is equipped with a transmitting probe 110 for emitting an ultrasonic beam, and an eccentrically placed receiving probe 120 that is installed on the opposite side of the transmitting probe 110 with respect to the test object E to receive an ultrasonic beam. The position of the eccentrically placed receiving probe 120 is adjusted so that an eccentric distance L between a transmitting sound axis AX1 of the transmitting probe 110 and a receiving sound axis AX2 of the eccentrically placed receiving probe 120 becomes larger than zero.SELECTED DRAWING: Figure 1

Description

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

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

The technique described in Patent Document 1 is known for an ultrasonic inspection apparatus. In the ultrasonic inspection apparatus described in Patent Document 1, a square wave burst signal composed of a predetermined number of continuous negative rectangular waves is applied to a transmission ultrasonic probe arranged to face the subject through air. The ultrasonic waves that are placed facing the subject via air and propagate through the subject with the received ultrasonic probe are converted into a transmitted wave signal. The presence or absence of defects in the subject is determined based on the signal level of this transmitted wave signal. Further, the transmitting ultrasonic probe and the receiving ultrasonic probe are contact type in which the acoustic impedance of the transducer and the front plate attached to the transmission / reception side of the ultrasonic wave of the transducer is used in contact with the subject. It is set lower than the ultrasonic probe.

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

In the ultrasonic inspection apparatus described in Patent Document 1, in a defect portion smaller than the magnitude (beam diameter) of the ultrasonic beam, there are many ultrasonic beams transmitted around the defect portion, and a signal change derived from the defect portion is detected. hard. Therefore, there is room for improvement in the detection performance of the defective portion.
An object to be solved by the present invention is to provide an ultrasonic inspection apparatus and an ultrasonic inspection method having excellent detection performance of a defective portion, particularly detection sensitivity.

The ultrasonic inspection device of the present invention is an ultrasonic inspection device that inspects the inspected object by injecting an ultrasonic beam into the inspected object via a gas, and the ultrasonic waves to the inspected object. The scanning measuring device includes a scanning measuring device that operates and measures a beam, and a control device that controls the drive of the scanning measuring device. The scanning measuring device includes a transmission probe that emits the ultrasonic beam and the subject to be inspected. It is provided with an eccentric arrangement receiving probe installed on the opposite side of the transmitting probe to receive the ultrasonic beam, and the eccentric distance between the transmitting sound axis of the transmitting probe and the receiving sound axis of the eccentric arrangement receiving probe is larger than zero. The eccentric arrangement receiving probe is arranged so as to be. Other solutions will be described later in the form for carrying out the invention.

According to the present invention, it is possible to provide an ultrasonic inspection apparatus and an ultrasonic inspection method having excellent detection performance of a defective portion, particularly detection sensitivity.

It is a figure which shows the structure of the ultrasonic inspection apparatus of 1st Embodiment. It is a figure explaining the transmission sound axis, the reception sound axis and the eccentric distance, and is the case where the transmission sound axis and the reception sound axis extend in the vertical direction. It is a figure explaining the transmission sound axis, the reception sound axis and the eccentric distance, and is the case where the transmission sound axis and the reception sound axis extend incline. It is a functional block diagram of a control device. It is sectional drawing which shows the structure of a transmission probe. It is the reception waveform from the eccentric arrangement reception probe, and is the figure which shows the reception waveform in the sound part N of the inspected body E. It is the reception waveform from the eccentric arrangement reception probe, and is the figure which shows the reception waveform in the defect part D of the inspected body E. It is a figure which shows the example of the plot of the signal strength data. It is a propagation path of the ultrasonic beam in this embodiment, and is the figure which shows the case where the ultrasonic beam is incident on the sound part. It is a propagation path of the ultrasonic beam in this embodiment, and is the figure which shows the case where the ultrasonic beam is incident on the defect part. It is a figure which shows the propagation path of the ultrasonic beam by the conventional ultrasonic inspection method, and is the figure which shows the time of incident on a sound part. It is a figure which shows the propagation path of the ultrasonic beam by the conventional ultrasonic inspection method, and is the figure which shows the time of incident on the defect part. It is a figure which shows the plot of the signal strength data by the conventional ultrasonic inspection method. It is a figure which shows the interaction between the defect part and an ultrasonic beam in the body under test, and is the figure which shows the state which receives the ultrasonic beam which reaches directly. It is a figure which shows the interaction between a defective part in a test body and an ultrasonic beam, and is a figure which shows the state of receiving a scattered wave. It is a flowchart which shows the ultrasonic inspection method of 1st Embodiment. It is a figure which shows the hardware configuration of a control device. It is a figure which shows the relationship between the transmission probe and the eccentric arrangement receive probe in the ultrasonic inspection apparatus which concerns on 2nd Embodiment. It is a figure explaining the relationship between the beam incident area in a transmitting probe and the beam incident area in an eccentric arrangement receiving probe. It is a figure which shows the example of the eccentric arrangement receiving probe which concerns on 3rd Embodiment. It is a figure which shows the structure of the scanning measurement apparatus of the ultrasonic inspection apparatus which concerns on 4th Embodiment. It is a figure explaining the reason why the effect by 4th Embodiment occurs. It is a figure which shows the structure of the ultrasonic inspection apparatus which concerns on 5th Embodiment. It is a functional block diagram of the ultrasonic inspection apparatus which concerns on 5th Embodiment. It is a figure which shows the arrangement of the eccentric arrangement receiving probe in the 6th Embodiment. It is a figure which shows the arrangement of the eccentric arrangement receiving probe in 7th Embodiment, and is the figure which the unit probe is inclined and arranged. It is a figure which shows the arrangement of the eccentric arrangement receiving probe in 7th Embodiment, and is the figure which arranged the unit probe in the vertical direction. It is a figure which shows the structure of the ultrasonic inspection apparatus in 8th Embodiment. It is a functional block diagram of the ultrasonic inspection apparatus in 8th Embodiment. It is a figure which shows the structure of the defect information determination part of the ultrasonic inspection apparatus of 9th Embodiment. It is a figure which shows the change in the measurement point of the received signal received by a coaxial arrangement receiving probe. It is a figure which shows the change in the measurement point of the received signal received by an eccentric arrangement receiving probe. It is a figure which shows the change in the measurement point of the interference signal synthesized by the interference signal generation part 231. It is a figure which shows the structure of the ultrasonic inspection apparatus of 10th Embodiment. It is a figure which shows the structure of the ultrasonic inspection apparatus of 11th Embodiment. It is a figure which shows the structure of the ultrasonic inspection apparatus of the twelfth embodiment.

Hereinafter, embodiments (referred to as embodiments) for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and for example, different embodiments can be combined or arbitrarily modified as long as the effects of the present invention are not significantly impaired. Further, the same members shall be designated by the same reference numerals, and duplicate description will be omitted. Furthermore, those having the same function shall be given the same name. The contents of the illustration are merely schematic, and for the convenience of illustration, the actual configuration may be changed to the extent that the effect of the present invention is not significantly impaired.

FIG. 1 is a diagram showing a configuration of an ultrasonic inspection device Z according to the first embodiment. In FIG. 1, the scanning measuring device 1 is shown in a schematic cross-sectional view. Further, a coordinate system of three orthogonal axes including the x-axis as the direction orthogonal to the paper surface, the y-axis as the left-right direction of the paper surface, and the z-axis as the vertical direction of the paper surface is shown.

The ultrasonic inspection apparatus Z inspects the inspected body E by injecting an ultrasonic beam U (FIG. 4) into the inspected body E via a gas. The gas is, for example, air, and the inside of the housing 101 of the scanning measuring device 1 is hollow. As shown in FIG. 1, the ultrasonic inspection device Z includes a scanning measurement device 1, a control device 2, and a display device 3. The display device 3 is connected to the control device 2.

The scanning measuring device 1 scans and measures the ultrasonic beam U on the object E to be inspected, includes a sample table 102 fixed to the housing 101, and mounts the object E to be inspected on the sample table 102. Placed. The object E to be inspected is arbitrary as long as it is made of a material having a speed of sound faster than that of a gas such as air. The object E to be inspected is, for example, a solid material, and more specifically, for example, a metal, glass, resin material, or a composite material such as CFRP (carbon fiber reinforced plastic, Carbon-Fiber Reinforced Plastics). Further, in the example of FIG. 1, the inspected body E has a defective portion D inside. The defective portion D is a cavity or the like. In the body E to be inspected, the portion other than the defective portion D is referred to as a sound portion N.

The scanning measuring device 1 includes a probe P (see FIG. 4), and has a transmitting probe 110 that emits an ultrasonic beam U and an eccentric arrangement receiving probe 120. The transmission probe 110 is installed in the housing 101 via the transmission probe scanning unit 103, and emits the ultrasonic beam U. The eccentric arrangement receiving probe 120 is a receiving probe 121 installed on the opposite side of the transmitting probe 110 with respect to the inspected body E to receive the ultrasonic beam U. The eccentric arrangement receiving probe 120 has a receiving sound axis AX2 at a position different from the transmitting sound axis AX1 of the transmitting probe 110. The distance between the transmission sound axis AX1 and the reception sound axis AX2 is the eccentric distance L. The eccentric arrangement receiving probe 120 is installed in the housing 101 via the receiving probe scanning unit 104.
In the present specification, among the receiving probes 121 that receive ultrasonic waves, those arranged at a position where the eccentric distance L is zero or more are defined as an eccentric arrangement receiving probe 120, and the eccentric distance L is set to a position where the eccentric distance L is zero. The arranged one is defined as the coaxially arranged receiving probe 140. In other words, the receiving probe 121 is a term that includes the eccentric arrangement receiving probe 120 and the coaxially arranged receiving probe 140.

Here, "the opposite side of the transmission probe 110" means the space on the opposite side (opposite side in the z-axis direction) of the space in which the transmission probe 110 is located, out of the two spaces separated by the object E to be inspected. Yes, it does not mean that the x and y coordinates are on the same opposite side (that is, the positions symmetrical with respect to the xy plane). As shown in FIG. 1, the transmission probe 110 and the eccentric arrangement reception probe 120 are installed so that the transmission sound axis AX1 and the reception sound axis AX2 deviate by the eccentric distance L. The specific contents of the transmission sound axis AX1, the reception sound axis AX2, and the eccentric distance L will be described later.

As the receiving probe scanning unit 104 moves, the eccentric arrangement receiving probe 120 scans the sample table 102 in the x-axis and y-axis directions. The transmitting probe 110 and the eccentric arrangement receiving probe 120 scan while maintaining the eccentric distance L in the x-axis direction or the y-axis direction with the inspected object E sandwiched between them (thick double-headed arrow).

The details of each of the scanning measuring devices 1 will be described later, but the eccentric distance L is set as follows. That is, the eccentric distance L is set to a distance at which the scattered wave U1 generated by the scattering of the ultrasonic beam U at the defective portion D of the inspected body E can be received. Alternatively, the eccentric arrangement when the inspected body E is incident on the defective portion D is eccentric so that the received signal strength at the receiving probe 120 is larger than the received signal strength when the inspected body E is incident on the healthy portion N. The distance L is set. Alternatively, the eccentricity distance L is set to a distance at which a received signal other than noise is not detected when the sound portion N of the inspected body E is irradiated.

The scanning measuring device 1 is an eccentric distance adjusting unit that adjusts the position of at least one of the transmitting probe 110 and the eccentric arrangement receiving probe 120 so that the eccentric distance L between the transmitting sound axis AX1 and the receiving sound axis AX2 becomes larger than zero. 105 is provided. The eccentric distance adjusting unit 105 (eccentric distance adjusting mechanism) is provided in the receiving probe scanning unit 104 installed in the housing 101. The eccentric distance adjusting unit 105 is provided with an eccentric arrangement receiving probe 120. The eccentric distance adjusting unit 105 can move the eccentric arrangement receiving probe 120 independently of the position of the receiving probe scanning unit 104, and the deviation between the receiving sound axis AX2 and the transmitting sound axis AX1 can be set to be the eccentric distance L. The eccentric distance adjusting unit 105 may be provided on the transmission probe scanning unit 103 side. That is, it suffices if the deviation between the reception sound axis AX2 and the transmission sound axis AX1 can be set to be the eccentric distance L. Therefore, even if the eccentric distance adjusting unit 105 is provided on the reception probe 121 side, it is provided on the transmission probe 110 side. You may.

A control device 2 is connected to the scanning measurement device 1. The control device 2 controls the drive of the scanning measurement device 1, and moves (scans) the transmitting probe 110 and the eccentric arrangement receiving probe 120 by instructing the transmitting probe scanning unit 103 and the receiving probe scanning unit 104. Control. As the transmitting probe scanning unit 103 and the receiving probe scanning unit 104 move synchronously in the x-axis and y-axis directions, the transmitting probe 110 and the eccentric arrangement receiving probe 120 scan the inspected object E in the x-axis and y-axis directions. do. Further, the control device 2 emits an ultrasonic beam U from the transmitting probe 110 and performs waveform analysis based on the signal acquired from the eccentric arrangement receiving probe 120.

In the present embodiment, the inspected body E is fixed to the housing 101 via the sample table 102, that is, the inspected body E is fixed to the housing 101 and is eccentric with the transmission probe 110. An example of scanning with the arrangement receiving probe 120 is shown. On the contrary, the transmitting probe 110 and the eccentric arrangement receiving probe 120 may be fixed to the housing 101, and the object E to be inspected may move to perform scanning.

A gas phase, which is a gas, is interposed between the transmitting probe 110 and the inspected body E, and between the eccentric arrangement receiving probe 120 and the inspected body E. In other words, the ultrasonic inspection device Z is a non-contact type ultrasonic inspection device Z in which neither the transmission probe 110 nor the eccentric arrangement receiving probe 120 comes into contact with the inspected object E.

The transmission probe 110 is a convergent transmission probe 110. On the other hand, the eccentric arrangement receiving probe 120 uses a probe whose convergence is looser than that of the transmitting probe 110. In the present embodiment, the eccentric arrangement receiving probe 120 uses a non-convergent probe having a planar probe surface. By using such a non-convergent eccentric arrangement receiving probe 120, it is possible to collect information on the defect portion D over a wide range.

In the present embodiment, the receiving probe 120 is displaced by the eccentric distance L in the x-axis direction of FIG. 1 with respect to the transmitting probe 110, but is displaced in the y-axis direction of FIG. The eccentric arrangement receiving probe 120 may be arranged. Alternatively, the eccentric arrangement receiving probe 120 may be arranged at L1 in the x-axis direction and L2 in the y-axis direction (that is, the positions of (L1, L2) when the position of the transmitting probe 110 in the xy plane is the origin). ..

FIG. 2A is a diagram illustrating a transmission sound axis AX1, a reception sound axis AX2, and an eccentric distance L, and is a case where the transmission sound axis AX1 and the reception sound axis AX2 extend in the vertical direction. FIG. 2B is a diagram illustrating a transmission sound axis AX1, a reception sound axis AX2, and an eccentric distance L, and is a case where the transmission sound axis AX1 and the reception sound axis AX2 are inclined and extended.

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

Further, the reception sound axis AX2 is defined as the sound axis of the propagation path of the virtual ultrasonic beam when it is assumed that the eccentric arrangement reception probe 120 emits the ultrasonic beam U. In other words, the reception sound axis AX2 is the central axis of the virtual ultrasonic beam assuming that the eccentric arrangement receiving probe 120 emits the ultrasonic beam U.
As a specific example, the case of a non-convergent receiving probe having a planar probe surface will be described. In this case, the direction of the received sound axis AX2 is the normal direction of the probe surface, and the axis passing through the center point of the probe surface is the received sound axis AX2. If the probe surface is rectangular, its center point is defined as the intersection of the diagonals of the rectangle.
The reason that the direction of the reception sound axis AX2 is the normal direction of the probe surface is that the virtual ultrasonic beam radiated from the reception probe is emitted in the normal direction of the probe surface. Even when receiving ultrasonic waves, the ultrasonic beam incident in the normal direction of the probe surface can be received with high sensitivity.

The eccentric distance L is defined by the distance between the transmission sound axis AX1 and the reception sound axis AX2. Therefore, as shown in FIG. 2B, when the ultrasonic beam U emitted from the transmission probe 110 is refracted, the eccentricity distance L is the distance between the refracting transmission sound axis AX1 and the reception sound axis AX2. Defined. In the ultrasonic inspection apparatus Z of the present embodiment, the transmission probe 110 and the eccentric arrangement receiving probe 120 are adjusted by the eccentric distance adjusting unit 105 so that the eccentric distance L defined in this way is a distance larger than zero. As a result, the ultrasonic beam U emitted from the transmitting probe 110 and transmitted around the defective portion D can be reduced, and the signal change derived from the defective portion D in the receiving probe 121 can be easily detected.

However, in the present embodiment, as a preferred example, the eccentric arrangement receiving probe 120 receives the scattered wave U1 generated by the scattering of the ultrasonic beam U at the defect portion D. Since the scattered wave U1 is generated by the presence of the defective portion D, the detection accuracy of the defective portion D can be further improved by detecting the scattered wave U1. In the following example, for the sake of simplification of the description, the present embodiment will be described by taking as an example an eccentric arrangement receiving probe 120 installed at a position where the scattered wave U1 can be received.

FIG. 2A shows a case where the transmission probe 110 is arranged in the normal direction on the surface of the inspected body E. In FIGS. 2A and 2B, the transmission sound axis AX1 is indicated by a solid arrow. Further, the received sound axis AX2 is indicated by an arrow of a alternate long and short dash line. In FIGS. 2A and 2B, the position of the receiving probe 121 shown by the broken line is the position where the eccentric distance L is zero, and the receiving probe 121 in which the transmitting sound axis AX1 and the receiving sound axis AX2 coincide with each other is the coaxially arranged receiving probe 140. Is. Further, the receiving probe 121 shown by a solid line is an eccentric arrangement receiving probe 120 arranged at a position having an eccentric distance L larger than zero. When the transmission probe 110 is installed so that the transmission sound axis AX1 is perpendicular to the horizontal plane (xy plane in FIG. 1), the propagation path of the ultrasonic beam U is not refracted. That is, the transmission sound axis AX1 is not refracted.

FIG. 2B is a diagram showing a case where the transmission probe 110 is arranged at an angle α from the normal direction on the surface of the inspected body E. In FIG. 2B as well as in FIG. 2A, the transmission sound axis AX1 is indicated by a solid arrow, and the reception sound axis AX2 is indicated by a one-dot chain line arrow. In the case of the example shown in FIG. 2B, as described above, the propagation path of the ultrasonic beam U is refracted at the refraction angle β at the interface between the inspected body E and the air. Therefore, the transmission sound axis AX1 bends (refracts) as shown by the solid arrow in FIG. 2B. In this case, the position of the coaxially arranged receiving probe 140 shown by the broken line is the position where the eccentric distance L is zero because it is located on the transmission sound axis AX1. Then, as described above, even when the ultrasonic beam U is refracted, the eccentric arrangement receiving probe 120 is arranged so that the distance between the transmitting sound axis AX1 and the receiving sound axis AX2 is L. In the example shown in FIG. 1, since the transmission probe 110 is installed in the normal direction on the surface of the inspected body E, the eccentric distance L is as shown in FIG. 2A.

The eccentricity distance L is set at a position where the signal strength at the defective portion D is larger than the received signal at the healthy portion N of the inspected body E. This point will be described later.

FIG. 3 is a functional block diagram of the control device 2. The control device 2 includes a transmission system 210, a reception system 220, a data processing unit 201, a scan controller 204, a drive unit 202, and a position measurement unit 203.

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

The receiving system 220 is a system for detecting a received signal output from the eccentric arrangement receiving probe 120. The signal output from the eccentric arrangement 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 (see FIG. 6) described later from the received signal. The generated signal strength data is sent to the data processing unit 201.

The data processing unit 201 processes the acquired information into a desired form, such as imaging information about the defect portion D of the inspected body E and detecting the presence or absence of the defect portion D. The images and information generated by the data processing unit 201 are displayed on the display device 3.

The scan controller 204 drives and controls the transmission probe scanning unit 103 and the reception probe 104 shown in FIG. The drive control of the transmission probe scanning unit 103 and the reception probe 104 is performed through the drive unit 202. Further, the scan controller 204 measures the position information of the transmission probe 110 and the eccentric arrangement reception probe 120 via the position measurement unit 203.

Here, the data processing unit 201 plots and images the signal strength data at each position based on the position information of the transmission probe 110 and the eccentric arrangement reception probe 120 received from the scan controller 204, and displays the image on the display device 3. indicate. As will be described later, in the present embodiment, the signal strength data acquired by the defective portion D is larger than the signal strength data of the sound portion N. Therefore, when the signal strength data is plotted against the (x, y) scanning position of the transmission probe 110, an image showing where the defect is located at the (x, y) position can be obtained. The display device 3 displays an image showing the defect position.

FIG. 4 is a schematic cross-sectional view showing the structure of the transmission probe 110. In FIG. 4, only the outer shell of the emitted ultrasonic beam U is shown for simplification, but in reality, the normal vector direction of the probe surface 114 covers the entire area of the probe surface 114. A large number of ultrasonic beams U are emitted.

The transmission probe 110 is configured to converge the ultrasonic beam U. As a result, the minute defect portion D in the inspected body E can be detected with high accuracy. The reason why the minute defect portion D can be detected will be described later. The transmission probe 110 includes a transmission probe housing 115, and a probe P inside the transmission probe housing 115. The probe P includes a backing 112, an oscillator 111, and a matching layer 113. The probe P is connected to the connector 116 by a lead wire 118. Further, the connector 116 is connected to the power supply device (not shown) and the control device 2 by the lead wire 117.

FIG. 5A is a reception waveform from the eccentric arrangement reception probe 120, and is a diagram showing a reception waveform at the sound portion N of the inspected body E. FIG. 5B is a reception waveform from the eccentric arrangement reception probe 120, and is a diagram showing a reception waveform at the defective portion D of the inspected body E. FIG. 5B shows a received signal when the transmitting probe 110 is arranged at the xy coordinate position of the cavity (defect portion D) having a width of 2 mm provided in the object E to be inspected. In FIGS. 5A and 5B, the time indicates the elapsed time since the burst wave was applied to the transmission probe 110, and a stainless steel plate having a thickness of 2 mm was used as the inspected body E. A burst wave having a frequency of 800 kHz was applied to the transmission probe 110. More specifically, a burst wave composed of 10 sine waves was applied to the inspected object E at regular intervals.

In FIG. 5A, no significant signal was observed, but in FIG. 5B, a significant signal was observed 90 microseconds after the burst wave was applied to the transmission probe 110. The 90 microsecond delay until this significant signal is observed is due to the time it takes for the scattered wave U1 to reach the eccentric arrangement receiving probe 120 from the emission of the ultrasonic beam U. Specifically, while the speed of sound in the air is 340 (m / s), it is about 6000 (m / s) in the stainless steel constituting the object E to be inspected, so a delay of 90 microseconds occurs. ..

FIG. 6 is a diagram showing an example of plotting signal strength data. In this example, the transmission probe 110 and the eccentric arrangement reception probe 120 are scanned in the x-axis direction for the defective portion D having a width of 2 mm, and the signal is extracted from the reception signal (receive signal shown in FIG. 5B) at the x-axis position. The intensity data is plotted. In the present embodiment, the signal strength data extraction method extracts the Peak To Peak value of the received signal shown in FIG. 5B, that is, the difference between the maximum value and the minimum value in an appropriate time domain. As another example of the method for extracting signal strength data, the received signal shown in FIG. 5B may be converted into a frequency component by signal processing such as a short-time Fourier transform, and the strength of an appropriate frequency component may be extracted. Further, as the signal strength data, the correlation function may be calculated with reference to an appropriate reference wave. In this way, the signal strength data is acquired corresponding to each scanning position of the transmission probe 110.

In the plot of the signal strength data shown in FIG. 6, the cavity having a width of 2 mm (defect portion D) corresponds to the reference numeral D1 in FIG. The sound level signal is in the sound portion N (the portion other than the reference numeral D1) of the inspected body E, whereas the received signal is significantly larger in the position where the defective portion D is inside (reference numeral D1). I understand.

Therefore, the eccentric distance adjusting unit 105 sets the eccentric distance L so that the intensity of the received signal at the time of incident on the defective portion D is larger than the intensity of the received signal at the time of incident on the sound portion N. It is preferable to adjust. By doing so, the defective portion D can be detected based on the received signal strength. Such an eccentric distance L is, for example, a distance between the reception sound axis AX2 of the eccentric arrangement reception probe 120 and the transmission sound axis AX1 of the transmission probe 110 arranged at a position where the scattered wave U1 (described later) can be received. The eccentric distance adjusting unit 105 is composed of, for example, an actuator, a motor, or the like, although none of them is shown.

Further, 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 sound portion N is irradiated. That is, it is preferable that the eccentric distance adjusting unit 105 sets the eccentric distance L so that a significant received signal is not output in the sound portion N of the inspected body E. By doing so, the SN ratio can be increased, the defective portion D can be determined at the location where the received signal other than noise is detected, and the defective portion D can be detected.

The eccentricity distance L can be determined, for example, by using a standard sample made of the same material as the inspected body E and having a defect portion D inside. Then, the defect portion D of the standard sample is irradiated with the ultrasonic beam U, and the eccentric distance L can be determined based on the position where the ultrasonic beam U or the scattered wave U1 can be received.

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

FIG. 7A is a propagation path of the ultrasonic beam U in the present embodiment, and is a diagram showing a case where the ultrasonic beam U is incident on the sound portion N. FIG. 7B is a propagation path of the ultrasonic beam U in the present embodiment, and is a diagram showing a case where the ultrasonic beam U is incident on the defective portion D.

As shown in FIGS. 7A and 7B, the ultrasonic beam U emitted from the transmission probe 110 is incident on the inspected body E. As shown in FIG. 7A, when the ultrasonic beam U is incident on the sound portion N, the ultrasonic beam U passes so as to converge toward the transmission sound axis AX1. Therefore, the received signal is not observed by the eccentric arrangement receiving probe 120 arranged while maintaining the eccentric distance L. On the other hand, as shown in FIG. 7B, when the ultrasonic beam U is incident on the defective portion D, the ultrasonic beam U is scattered by the defective portion D, and the scattered wave U1 is eccentrically installed in the eccentric arrangement receiving probe. Received at 120. Therefore, a significant received signal is observed.

In this way, the scattered wave U1 scattered by the defect portion D in the inspected body E is observed by the eccentric arrangement receiving probe 120. Therefore, the received signal in the defective portion D is larger than the received signal in the sound portion N. That is, it is determined that the defect portion D is located at a position where the signal is large. Therefore, it is preferable that the eccentric distance adjusting unit 105 adjusts the eccentric distance L to a distance at which the scattered wave U1 generated by the scattering of the irradiated ultrasonic beam U at the defective portion D of the inspected body E can be received. .. By doing so, the scattered wave U1 peculiar to the defective portion D can be detected, and the detection accuracy of the defective portion D can be improved.

The eccentricity distance L is preferably such that the ultrasonic beam U emitted from the transmission probe 110 is not received and only the scattered wave U1 can be selectively received. As a result, the SN ratio can be increased and the detection performance of the defective portion D, particularly the detection sensitivity, can be improved. Here, "high detection sensitivity" means that a defect portion D smaller than that of the conventional method can be detected. That is, the lower limit of the size of the detectable defect portion D is smaller than that of the conventional method.

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

FIG. 8A is a diagram showing a propagation path of the ultrasonic beam U in the conventional ultrasonic inspection method, and is a diagram showing the time of incident on the sound portion N. FIG. 8B is a diagram showing a propagation path of the ultrasonic beam U in the conventional ultrasonic inspection method, and is a diagram showing the time of incident on the defective portion D. In the conventional ultrasonic inspection method, for example, as described in Patent Document 1, the coaxially arranged receiving probe 140 as the transmitting probe 110 and the receiving probe 121 so that the transmitting sound axis AX1 and the receiving sound axis AX2 coincide with each other. Is placed.

As shown in FIG. 8A, when the ultrasonic beam U is incident on the sound portion N of the inspected body E, the ultrasonic beam U passes through the inspected body E and reaches the coaxially arranged receiving probe 140. Therefore, the received signal becomes large. On the other hand, as shown in FIG. 8B, when the ultrasonic beam U is incident on the defective portion D, the received signal is reduced because the defective portion D blocks the transmission of the ultrasonic beam U. In this way, the defective portion D is detected by reducing the received signal. This is as shown in Patent Document 1.

Here, as shown in FIGS. 8A and 8B, a method of detecting the defective portion D by reducing the received signal by blocking the transmission of the ultrasonic beam U in the defective portion D is described here as a “blocking method”. I will call it. On the other hand, the inspection method for detecting the scattered wave U1 in the defective portion D as in the present embodiment will be referred to as a "scattering method".

FIG. 9 is a diagram showing a plot of signal intensity data in a conventional ultrasonic inspection method. This figure was used in FIG. 6 above by the inventors in the ultrasonic inspection method by the blocking method shown in FIGS. 8A and 8B, that is, the arrangement in which the transmission sound axis AX1 and the reception sound axis AX2 are matched. It is a signal strength graph which inspected the inspected body E which has the same defect part D as the inspected body E. In FIG. 9, the portion of the reference numeral D1 is a portion corresponding to the defect portion D.

In FIG. 9, a decrease in the signal is observed at the center position (position is 0 mm) of the defect portion D, but the amount of decrease is small. It is considered that this is because the defect portion D, which is smaller than the size of the ultrasonic beam U, has a large number of ultrasonic beams U passing around the defect portion D. Therefore, in the blocking method in which the transmission sound axis AX1 and the reception sound axis AX2 are matched, it is difficult to detect the signal change derived from the defective portion D, and the detection sensitivity is low.

On the other hand, by shifting the transmission sound axis AX1 and the reception sound axis AX2, the signal strength received by the eccentric arrangement reception probe 120 is transmitted around the defect portion D smaller than the size of the ultrasonic beam U. The signal of the ultrasonic beam U can be reduced. As a result, the signal strength caused by the defect portion D can be reduced by a relatively large amount, and the detection performance of the defect portion D, particularly the detection sensitivity can be improved. Above all, as shown in FIG. 6 above, according to the configuration by the scattering method suitable for the present embodiment, it can be seen that the position of the defective portion D can be clearly detected as compared with the result of FIG. 9 by the blocking method. That is, when the reception result shown in FIG. 9, which is a comparative example, and the reception result of the method according to the present embodiment shown in FIG. 6 are compared, the method according to the present embodiment shown in FIG. 6 has a higher SN ratio. ..

As described above, the reason why the scattering method of the present embodiment can obtain a high SN ratio will be described with reference to FIGS. 10A and 10B.

FIG. 10A is a diagram showing the interaction between the defective portion D and the ultrasonic beam U in the inspected body E, and shows how the ultrasonic beam U (hereinafter referred to as “direct wave U3”) that reaches directly is received. It is a figure which shows. The epilogue U3 will be described later. FIG. 10B is a diagram showing the interaction between the defective portion D and the ultrasonic beam U in the inspected body E, and is a diagram showing how the scattered wave U1 is received. Here, a case where the size of the defect portion D is smaller than the width of the ultrasonic beam U (hereinafter referred to as the beam width BW) will be considered. The beam width BW here is the width of the ultrasonic beam U when it reaches the defect portion D.

Further, since FIGS. 10A and 10B schematically show the shape of the ultrasonic beam U in the minute region near the defect portion D, the ultrasonic beam U is drawn in parallel, but it is actually converged. The ultrasonic beam U. Further, the positions of the receiving probe 121 in FIGS. 10A and 10B are conceptually marked for easy understanding, and the positions and shapes of the receiving probe 121 are not accurately scaled. That is, considering the magnified scale of the shape of the defect portion D and the ultrasonic beam U, the receiving probe 121 is located at a position farther in the vertical direction of the drawing than the positions shown in FIGS. 10A and 10B. Here, the receiving probe 121 is a coaxially arranged receiving probe 140 in FIG. 10A, and means an eccentric arrangement receiving probe 120 in FIG. 10B.

The ultrasonic beam U has a finite width in the vicinity of the defect portion D even if it is converged and incident. This is defined as the beam width BW at the position of the defective portion D. Incidentally, FIGS. 10A and 10B show a case where the beam width BW at the position of the defect portion D is wider than the size of the defect portion D.

FIG. 10A is a diagram showing the case of a blocking method in which the transmission sound axis AX1 and the reception sound axis AX2 are matched. When the defect portion D is smaller than the beam width BW, a part of the ultrasonic beam U is blocked, so that the received signal is reduced, but it does not become zero. For example, when the cross-sectional area of the defective portion D is 20% of the beam cross-sectional area defined by the beam width BW, the received signal is reduced by only about 20%, so that it is difficult to detect the defective portion D. That is, in the case as shown in FIG. 10A, the received signal is reduced by only 20% at the place where the defective portion D exists (see FIG. 9).

FIG. 10B is a diagram showing the case of the preferred method of the present embodiment, that is, the case of the scattering method. In the scattering method, when the ultrasonic beam U does not hit the defective portion D, the ultrasonic beam U does not enter the eccentric arrangement receiving probe 120, so that the received signal is zero. Then, as shown in FIG. 10B, even when a part of the ultrasonic beam U hits the defective portion D, the scattered wave U1 is observed by the eccentric arrangement receiving probe 120, so that the defective portion D is compared with the blocking method. Easy to detect. That is, if the defective portion D does not exist, the received signal becomes zero, and if the defective portion D exists even if it is minute, the received signal becomes non-zero. Therefore, it is possible to increase the SN ratio (see FIG. 6). As described above, according to the method (scattering method) according to the present embodiment, the defect portion D smaller than the beam width BW can be detected with high sensitivity. Here, "can be detected with high sensitivity" means that a defect portion D smaller than that of the conventional method can be detected. That is, the lower limit of the size of the detectable defect portion D is smaller than that of the conventional method.

Further, as shown in FIG. 10A, in the blocking method, the defective portion D is determined based on the amount of decrease from the received signal amount corresponding to the sound portion N as a reference. Therefore, it is preferable that the received signal in the sound portion N is a constant value. However, especially in ultrasonic waves propagating in gas, the intensity of reaching the receiving probe 121 is extremely small as compared with ultrasonic waves propagating in water. Therefore, it is preferable to amplify the received signal with a high amplification factor (gain). Therefore, a high-precision signal amplification circuit is preferable to keep the gain constant. On the other hand, in the scattering method according to the present embodiment, as shown in FIG. 6, the signal is almost zero in the sound portion N and the signal is observed in the defective portion D, so that the gain stability of the signal amplifier circuit is required. Can be made smaller. However, in FIG. 6 above, the value of the signal strength is raised by the offset value.

Further, in the present embodiment, a positive image can be obtained. That is, in the scattering method, a signal is not generated or is small in the sound portion N, and a new signal is generated or the signal is large in the defective portion D. That is, a positive image of the defect portion D can be obtained. On the other hand, in the blocking method, in the blocking method, the signal is large in the sound portion N and the signal is decreased in the defective portion D. That is, a negative image of the defective portion D can be obtained.

Further, the ultrasonic inspection device Z according to the present embodiment can be realized only by shifting the position of the coaxially arranged receiving probe 140 of the ultrasonic inspection device of the conventional blocking method by the eccentric distance L. That is, the ultrasonic inspection device that has been used so far can be used, and the installation cost can be reduced.

FIG. 11 is a flowchart showing the ultrasonic inspection method of the first embodiment. The ultrasonic inspection method of the first embodiment can be carried out by the above-mentioned ultrasonic inspection apparatus Z, and will be described with reference to FIGS. 1 and 3 as appropriate. The ultrasonic inspection method of the first embodiment inspects the inspected body E by injecting the ultrasonic beam U into the inspected body E (FIG. 1) via a gas. First, according to the command of the control device 2 (FIG. 3), the emission step S101 for emitting the ultrasonic beam U from the transmission probe 110 (FIG. 1) is performed. Subsequently, the reception step S102 for receiving the ultrasonic beam U (scattered wave U1 in this example) is performed in the eccentric arrangement receiving probe 120 (FIG. 1).

After that, the analysis step S103 for generating signal intensity data is performed based on the waveform signal of the received ultrasonic beam U (scattered wave U1 in this example). The analysis step S103 is performed by the waveform analysis unit 221 (FIG. 3), and the waveform analysis unit 221 extracts (generates) signal strength data from, for example, the received signal shown in FIG. 5B. The signal strength data can be extracted, for example, by the method described with reference to FIG. 6 above. In this way, the signal strength data is acquired corresponding to each scanning position of the transmission probe 110.

The scan position information of the transmission probe 110 and the eccentric arrangement reception probe 120 is transmitted from the position measurement unit 203 (FIG. 3) to the scan controller 204 (FIG. 3). The data processing unit 201 (FIG. 3) plots the signal strength data at each scanning position with respect to the scanning position information of the transmission probe 110 acquired from the scan controller 204. In this way, for example, the signal strength graph G shown in FIG. 6 above is obtained, and the signal strength data is visualized. Note that FIG. 6 shows a case where the scanning position information is one-dimensional (one direction). When the scanning position information is two-dimensional in x and y, the defect position is shown as a two-dimensional image by plotting the signal strength data, and the defect position is displayed on the display device 3.

Further, a determination step S104 is performed in which the presence or absence of the defective portion D of the inspected body E is determined by determining whether or not the signal strength data generated in the analysis step S103 is equal to or higher than a preset threshold value. The determination step S104 is performed by the data processing unit 201. In the determination step S104, it is determined whether or not the defect portion D is detected. When the value of the generated signal strength data is equal to or greater than a predetermined threshold value (determination step S104, Yes), the data processing unit 201 notifies the user that the defect unit D has been detected (notification step S105). The process of the notification step S105 may be performed after all the scans are completed. The notification that the defective portion D has been detected is displayed on, for example, the display device 3 (FIG. 3). After that, the data processing unit 201 advances the processing to step S111.

As a result of the determination step S104, when the value of the generated signal strength graph G is less than a predetermined threshold value (No), the data processing unit 201 determines whether or not the scanning is completed (step S111). When the scan is completed (Yes), the control device 2 ends the process. When scanning is not completed (No), the data processing unit 201 outputs a command to the driving unit 202 (FIG. 3) to move the transmitting probe 110 and the eccentric arrangement receiving probe 120 to the next scanning position (step). S112), the process is returned to the release step S101.

FIG. 12 is a diagram showing a hardware configuration of the control device 2. The control device 2 includes a memory 251 such as a RAM (Random Access Memory), a CPU (Central Processing Unit) 252, a ROM (Read Only Memory), a storage device 253 such as an HDD (Hard Disk Drive), and a NIC (Network) Network. Etc. 254, I / F (Interface) 255, etc. are provided.

Then, in the control device 2, a predetermined control program stored in the storage device 253 is loaded into the memory 251 and executed by the CPU 252. As a result, the data processing unit 201, the position measurement unit 203, the scan controller 204, the defect information determination unit 205, the waveform analysis unit 221 and the like in FIG. 3 are embodied.

FIG. 13 is a diagram showing the relationship between the transmission probe 110 and the eccentric arrangement reception probe 120 in the ultrasonic inspection apparatus Z according to the second embodiment. In the second embodiment, the relationship between the transmit probe 110 and the eccentric arrangement receive probe 120 will be described.

In the second embodiment, the convergence of the eccentric arrangement receiving probe 120 is looser than the convergence of the transmitting probe 110. The propagation path of the scattered wave U1 changes slightly depending on the depth of the defect portion D inside the inspected body E, the shape and inclination of the defect portion D, and the like. Therefore, in the second embodiment, the convergence of the eccentric arrangement receiving probe 120 is loosened so that the eccentric arrangement receiving probe 120 can detect the scattered wave U1 even if the path of the scattered wave U1 changes.

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

FIG. 14 is a diagram illustrating the relationship between the beam incident area T1 in the transmitting probe 110 and the beam incident area T2 in the eccentric arrangement receiving probe 120. The beam incident area T1 of the transmitting probe 110 is the crossing area of the ultrasonic beam U emitted from the transmitting probe 110 on the surface of the inspected body E. Further, the beam incident area T2 of the eccentric arrangement receiving probe 120 is the intersection area between the virtual ultrasonic beam U2 and the surface of the object E to be inspected assuming the case where the ultrasonic beam U is emitted from the eccentric arrangement receiving probe 120. be.

In addition, in FIG. 14, the path of the ultrasonic beam U shows the path when there is no inspected body E. When there is an inspected body E, the ultrasonic beam U is refracted on the surface of the inspected body E, so that it propagates in a path different from the path shown by the broken line. Here, as shown in FIG. 14, the beam incident area T2 of the eccentric arrangement receiving probe 120 in the inspected body E is larger than the beam incident area T1 of the transmitting probe 110 in the inspected body E. By doing so, the convergence of the eccentric arrangement receiving probe 120 can be made looser than the convergence of the transmitting probe 110.

Further, the focal length R2 of the eccentric arrangement receiving probe 120 is longer than the focal length R1 of the transmitting probe 110. Even in this way, the convergence of the eccentric arrangement receiving probe 120 can be made looser than the convergence of the transmitting probe 110. At this time, the distances from the inspected body E to the transmitting probe 110 and the eccentric arrangement receiving probe 120 are, for example, the same, but may not be the same.

As described above, in the second embodiment, the convergence of the eccentric arrangement receiving probe 120 is looser than the convergence of the transmitting probe 110. That is, the focal length R2 of the eccentric arrangement receiving probe 120 is set longer than the focal length R1 of the transmitting probe 110. As a result, the beam incident area T2 of the eccentric arrangement receiving probe 120 becomes wide, so that the scattered wave U1 in a wide range can be detected. As a result, even if the propagation path of the scattered wave U1 changes slightly, the scattered wave U1 can be detected by the eccentric arrangement receiving probe 120. As a result, a wide range of defective portions D can be detected.

Further, the focal point of the eccentric arrangement receiving probe 120 is located on the side of the transmitting probe 110 (above in the illustrated example) with respect to the focal point of the transmitting probe 110. By shifting the focus in this way, the scattered wave U1 can be easily received by the eccentric arrangement receiving probe 120, and the scattered wave U1 can be easily detected.

As the eccentric arrangement receiving probe 120, a non-convergent probe as used in the first embodiment may be used. Since the focal length R2 is infinite in the non-convergent probe, it is longer than the focal length R1 of the transmission probe 110. That is, even in the non-convergent eccentric arrangement receiving probe 120, the convergence of the eccentric arrangement receiving probe 120 is looser than the convergence of the transmission probe 110.

FIG. 15 is a diagram showing an example of an eccentric arrangement receiving probe 120 according to the third embodiment. It is a top view of the ultrasonic inspection apparatus Z, which saw the transmission probe 110 and the eccentric arrangement receive probe 120 from the minus side of the z-axis. That is, it is a figure seen from the eccentric arrangement receiving probe 120 side. In the third embodiment, the length b of the oscillator 111 (FIG. 4) of the eccentric arrangement receiving probe 120 in the eccentric direction of the receiving sound axis AX2 with respect to the transmitting sound axis AX1 is in the direction along the surface of the object E to be inspected. It is longer than the length a in the direction orthogonal to the eccentric direction. The lengths a and b are characteristic lengths, which mean the lengths of the sides of a rectangle for a rectangular oscillator, and the elliptical major axis or minor axis for an elliptical oscillator. means.

When the aspect ratio of the eccentric arrangement receiving probe 120 is set in this way, the scattered wave U1 is detected by the eccentric arrangement receiving probe 120 even if the depth of the defective portion D changes and the arrival position of the scattered wave U1 changes. be able to.

The scattered wave U1 is scattered in the radial direction about the transmission sound axis AX1. Therefore, when the eccentric arrangement receiving probe 120 is arranged at the position of FIG. 15, the scattered wave U1 is scattered in the longitudinal direction of the eccentric arrangement receiving probe 120 (the extending direction of the “length b”). In other words, the extending direction of the "length b" is the direction in which the scattered wave U1 is radiated. Therefore, by increasing the value of "length b", it is possible to detect the scattered wave U1 scattered at the defect portion D having 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 eccentric arrangement receiving probe 120.

There is no limitation on the lengths a and b, and the length b may be longer than the length a, that is, 1 <b / a, but the upper limit b / a (length b divided by length a) is used. Value) is, for example, 100 or less, preferably 50 or less.

Although the rectangular parallelepiped (rectangular) eccentric arrangement receiving probe 120 is shown as the eccentric arrangement receiving probe 120 in FIG. 15, the same effect can be obtained by making the elliptical shape and setting the major axis / minor axis ratio in the same manner. can get.

FIG. 16 is a diagram showing a configuration of a scanning measuring device 1 of the ultrasonic inspection device Z according to the fourth embodiment. In the fourth embodiment, the scanning measuring device 1 includes an installation angle adjusting unit 106 that adjusts the inclination of the eccentric arrangement receiving probe 120. As a result, the strength of the received signal can be increased, and the SN ratio (Signal to Noise ratio, signal noise ratio) of the signal can be increased. The installation angle adjusting unit 106 is composed of, for example, an actuator, a motor, or the like, although none of them is shown.

Here, the angle θ formed by the transmission sound axis AX1 and the reception sound axis AX2 is defined as the reception probe installation angle. In the case of FIG. 16, since the transmission probe 110 is installed in the vertical direction, the transmission sound axis AX1 is in the vertical direction. Therefore, the angle θ, which is the reception probe installation angle, is eccentric with the transmission sound axis AX1 (that is, the vertical direction). It is an angle formed by the normal of the probe surface of the receiving probe 120. Then, the installation angle adjusting unit 106 tilts the angle θ toward the side where the transmission sound axis AX1 exists, and sets the angle θ to a value larger than zero. That is, the eccentric arrangement receiving probe 120 is inclined arrangement. Specifically, the eccentric arrangement receiving probe 120 is inclined so as to satisfy 0 ° <θ <90 °, and the angle θ is, for example, 10 °, but the present invention is not limited to this.

Further, the eccentric distance L when the eccentric arrangement receiving probe 120 is inclined is defined as follows. An intersection C2 between the reception sound axis AX2 and the eccentric arrangement reception probe 120 (probe) is defined. Further, the intersection C1 between the transmission sound axis AX1 and the transmission probe 110 (probe P) is defined. The distance between the coordinate position (x1, y1) in which the position of the intersection C1 is projected on the xy plane and the coordinate position (x2, y2) in which the position of the intersection C2 is projected on the xy plane is defined as the eccentric distance L.

When the inventors actually detected the defective portion D by arranging the eccentric arrangement receiving probe 120 in an inclined manner in this way, the signal strength of the received signal increased three times.

FIG. 17 is a diagram illustrating the reason why the effect of the fourth embodiment occurs. The scattered wave U1 propagates in a direction deviating from the transmission sound axis AX1. Therefore, as shown in FIG. 17, when the scattered wave U1 reaches the outside of the inspected body E, it enters the inspected body E-external interface at an angle α2 that is non-zero with the normal vector on the surface of the inspected body E. do. The angle of the scattered wave U1 emitted from the surface of the inspected body E has an angle β2 which is a non-zero emission angle with respect to the normal direction of the surface of the inspected body E. The scattered wave U1 can be received most efficiently when the normal vector of the probe surface of the eccentric arrangement receiving probe 120 is matched with the traveling direction of the scattered wave U1. That is, the received signal strength can be increased by arranging the eccentric arrangement receiving probe 120 at an angle.

From the structure shown in FIG. 17, when the angle β2 of the ultrasonic beam U emitted from the inspected body E and the angle θ formed by the transmission sound axis AX1 and the reception sound axis AX2 match, the reception effect is most effective. It gets higher. However, even when the angle β2 and the angle θ do not completely match, the effect of increasing the received signal can be obtained. Therefore, as shown in FIG. 17, even if the angle β2 and the angle θ do not completely match, the angle β2 and the angle θ do not completely match. good.

In the scanning measuring device 1 of FIG. 16 above, the installation angle adjusting unit 106 is provided, and the eccentric arrangement receiving probe 120 is installed by the installation angle adjusting unit 106. The installation angle adjusting unit 106 can adjust the receiving probe installation angle of the eccentric arrangement receiving probe 120. Since the path of the scattered wave U1 changes slightly depending on the material of the object E to be inspected, the thickness, and the like, the optimum value of the receiving probe installation angle also changes. Therefore, by allowing the receiving probe installation angle to be adjusted by the installation angle adjusting unit 106, the receiving probe installation angle can be appropriately adjusted according to the material, thickness, and the like of the object E to be inspected.

Further, in the fourth embodiment, the eccentric arrangement receiving probe 120 is arranged in an inclined state with respect to the horizontal plane, but the transmitting probe 110 may also be arranged in an inclined state. Alternatively, the transmitting probe 110 may be arranged so as to be tilted with respect to the horizontal plane, and the probe surface of the eccentric arrangement receiving probe 120 may be arranged so as to be parallel to the horizontal plane (xy plane). In either case, as shown in FIG. 2B, the transmission sound axis AX1 and the reception sound axis AX2 are arranged in a staggered state.

FIG. 18 is a diagram showing a configuration of an ultrasonic inspection device Z according to a fifth embodiment. In a fifth embodiment, the eccentric arrangement receiving probe 120 includes a plurality of unit probes 120a. In the illustrated example, there are three unit probes 120a. The unit probes 120a are arranged at positions where the eccentric distance L (distance from the transmission sound axis AX1) is different.

The path of the scattered wave U1 changes slightly depending on the depth, shape, inclination, etc. of the defect portion D. For example, since the scattering angle at the time of scattering (the angle formed by the scattered wave U1 with respect to the transmission sound axis AX1) is usually about the same, the deeper the defect portion D, the closer the scattered wave U1 reaches the place closer to the transmission sound axis AX1. As the defect portion D becomes shallower, the scattered wave U1 reaches a place farther from the transmission sound axis AX1. Therefore, by using the information on which position of the unit probe 120a received by using the plurality of unit probes 120a, information on the defect portion D (depth of the defect portion D, etc.) can be obtained.

As the plurality of unit probes 120a, an array type probe 122 (described later with reference to FIGS. 28 and 29) in which a plurality of sound sensing elements 122a are housed in one housing may be used. In this case, the unit probes 120a of FIG. 18 correspond to sound sensing elements, respectively, and they are housed in one housing. The sound sensitive element is an element that converts ultrasonic waves into electric signals. As the sound-sensitive element, in addition to the piezoelectric element, a capacitive sound-sensitive element (CMUT, Capacitive Micro-machined Ultrasonic Transducer) or the like may be used.

FIG. 19 is a functional block diagram of the ultrasonic inspection device Z according to the fifth embodiment. The plurality of unit probes 120a are connected to the corresponding receiving systems 220a to 220c. The configuration of each receiving system 220a to 220c is the same as the configuration of the receiving system 220 shown in FIG. The outputs from the receiving systems 220a to 220c are input to the defect information determination unit 205.

The defect information determination unit 205 is provided in the control device 2 and receives the scattered wave U1 generated by the scattering of the irradiated ultrasonic beam U in the defect portion D of the inspected object E among the plurality of unit probes 120a. Based on the received signal of the unit probe 120a, the information regarding the defective portion D in the inspected object E (depth of the defective portion D, etc.) is determined. Specifically, the defect information determination unit 205 determines information regarding the defect unit D based on the waveform analysis results of the receiving systems 220a to 220c, respectively. What is based on the received signal is how much received signal (scattered wave U1) is detected by which unit probe 120a. By doing so, the accuracy of the position information of the defective portion D can be improved.

The output of the defect information determination unit 205 is input to the data processing unit 201. In the data processing unit 201, the information of the defect unit D is imaged and displayed on the display device 3 by matching with the position information from the scan controller 204 that scans the probe.

The defect information determination unit 205 may be provided as a part of the data processing unit 201.

FIG. 20 is a diagram showing the arrangement of the eccentric arrangement receiving probe 120 in the sixth embodiment. In this example, it is a plan view of the transmitting probe 110 and the eccentric arrangement receiving probe 120 as viewed from the minus side of the z-axis of FIG. 1, that is, the eccentric arrangement receiving probe 120 side. In the sixth embodiment, the eccentric arrangement receiving probe 120 is arranged two-dimensionally in the xy plane direction. That is, the eccentric arrangement receiving probe 120 includes a plurality of unit probes 120a having a rectangular shape in a 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 changes slightly depending on the shape of the defect portion D, the inclination direction, and the like. Therefore, as shown in FIG. 17, by arranging the unit probes 120a radially and recording in which direction the scattered wave U1 is detected, information such as the shape and the inclination direction of the defect portion D can be obtained with higher accuracy. be able to.

FIG. 21 is a diagram showing the arrangement of the eccentric arrangement receiving probe 120 in the seventh embodiment, and is a diagram in which the unit probe 120a is arranged in an inclined manner. A plurality of unit probes 120a are arranged symmetrically with respect to the transmission sound axis AX1. Therefore, at least two unit probes 120a are arranged at positions where the eccentricity distance L is the same. In the illustrated example, three unit probes 120a are symmetrically arranged on both sides of the transmission sound axis AX1 in a plan view including the transmission sound axis AX1. Then, two unit probes 120a are arranged at each position of the three different eccentric distances L. The unit probe 120a is arranged in an inclined manner in the same manner as in the fourth embodiment (FIG. 17) described above.

FIG. 22 is a diagram showing the arrangement of the eccentric arrangement receiving probe 120 in the seventh embodiment, and is a diagram in which the unit probe 120a is arranged in the vertical direction. A set of unit probes 120a are arranged symmetrically with respect to the transmission sound axis AX1. Therefore, at least two unit probes 120a are arranged at positions where the eccentricity distance L is the same.

By arranging at least two unit probes 120a at positions having the same eccentricity distance L, it is possible to detect scattered waves U1 scattered in a plurality of directions. Further, by arranging at least two unit probes 120a on both sides of the transmission sound axis AX1 in a plan view including the transmission sound axis AX1 (FIGS. 21 and 22), the scattered wave U1 in a wide range can be received. Further, the control device 2 actually detects the defective portion D when the scattered wave U1 is detected by the unit probes 120a on both sides, and determines that an error occurs when the scattered wave U1 is detected in only one of them. Can be done. As a result, the detection accuracy of the defective portion D can be improved.

FIG. 23 is a diagram showing the configuration of the ultrasonic inspection device Z according to the eighth embodiment. In the eighth embodiment, the receiving probe 121 further includes a coaxially arranged receiving probe 140 arranged at a position where the eccentric distance L is zero, in addition to the eccentric arrangement receiving probe 120. The coaxially arranged reception probe 140 is provided in the scanning measuring device 1, and is arranged so as to coincide with the transmission sound axis AX1 and the reception sound axis AX2. In the present specification, the receiving probe 121 arranged at a position where the eccentric distance L is zero is referred to as a coaxially arranged receiving probe 140.

The scanning measuring device 1 includes a coaxially arranged receiving probe 140 in addition to the configuration of the first embodiment (FIG. 1). The eccentric arrangement receiving probe 120 can be moved to a position where the scattered wave U1 can be received independently of the coaxial arrangement receiving probe 140 by the eccentric distance adjusting unit 105. When scanning the inspected object E, the transmission probe 110, the eccentric arrangement reception probe 120, and the coaxial arrangement reception probe 140 move integrally by the movement of the transmission probe scanning unit 103 and the reception probe scanning unit 104 in the xy plane. The output signal of the coaxially arranged receiving probe 140 is input to the control device 2.

As shown in FIG. 8B above, the coaxially arranged receive probe 140 receives the signal by the blocking method. Therefore, when there is a defect larger than the convergence diameter of the ultrasonic beam U, a decrease in the received signal is observed, so that the defect can be detected. On the other hand, for defects smaller than the convergence diameter of the ultrasonic beam U, the defect portion D can be detected by observing the scattered wave U1 with the eccentric arrangement receiving probe 120. Therefore, by providing the eccentric arrangement receiving probe 120 and the coaxial arrangement receiving probe 140, in addition to being able to detect a defect portion D smaller than the diameter of the ultrasonic beam U, a defect portion larger than the diameter of the ultrasonic beam U can be detected. D can also be detected.

FIG. 24 is a functional block diagram of the ultrasonic inspection device Z according to the eighth embodiment. The output signal of the eccentric arrangement receiving probe 120 is input to the receiving system 220a. The output signal of the coaxially arranged reception probe 140 is input to the reception system 220b. The output signal of the receiving system 220a and the output signal of the receiving system 220b are input to the defect information determination unit 205, respectively. The defect information determination unit 205 determines the presence or absence of the defect unit D using the two received signals, and outputs the result to the data processing unit 201.

A specific example of the processing method of the defect information determination unit 205 will be described. Regarding the received signal from the eccentric arrangement receiving probe 120, it is determined that the defect portion D exists at the scanning position where the signal is increased by a certain amount. Regarding the received signal from the coaxially arranged receiving probe 140, it is determined that the defective portion D exists at the position where the signal is reduced by a certain amount. The logical sum of the determinations based on the two signals is taken as the output of the defect information determination unit 205. That is, if it is determined that there is a defect in either the determination based on the reception signal of the eccentric arrangement reception probe 120 or the determination based on the reception signal of the coaxial arrangement reception probe 140, the defect information determination unit 205 is defective. It is determined that the part D exists.

By providing the eccentric arrangement receiving probe 120 and the coaxial arrangement receiving probe 140, it is possible to reduce the detection omission of the defect portion D and improve the detection performance.

FIG. 25 is a diagram showing the configuration of the defect information determination unit 205 of the ultrasonic inspection device Z according to the ninth embodiment. In the ninth embodiment, for example, the ultrasonic inspection apparatus Z shown in FIG. 23 can be used, and the signal of the direct wave U3 observed by the coaxially arranged receiving probe 140 and the signal of the scattered wave U1 received by the eccentric arrangement receiving probe 120 can be used. Small defects are detected using the interference signal generated by synthesizing.

The defect information determination unit 205 includes an interference signal generation unit 231, a scattered wave feature amount extraction unit 232a, a direct wave feature amount extraction unit 232b, an interference signal feature amount extraction unit 232c, and a signal integration processing unit 240. First, both the output signal of the reception system 220a and the output signal of the reception system 220b are input to the interference signal generation unit 231. The interference signal generation unit 231 is provided in the control device 2 and synthesizes the output signal of the eccentric arrangement receiving probe 120 (the signal of the scattered wave U1) and the output signal of the coaxial arrangement receiving probe 140 (the signal of the direct wave U3). Since the phase of the scattered wave U1 generated in the defect portion D and the phase of the direct wave U3 are different, the interference signals generated by the synthesis cancel each other out, and the amount of signal change in the defect portion D becomes large. As a result, it is possible to detect a defect D that is smaller than the conventional blocking type, which observes the signal change amount of the direct wave U3.

Here, the principle of generating the interference signal will be described again with reference to FIGS. 10A and 10B described above. FIG. 10A schematically shows the propagation path of the direct wave U3 received by the coaxially arranged receiving probe 140. FIG. 10B schematically shows the propagation path of the scattered wave U1 received by the eccentric arrangement receiving probe 120.

It is assumed that the size (diameter) of the defect portion D is smaller than the beam diameter of the transmitted ultrasonic beam U. 10A and 10B are schematic views assuming such a case. In this case, as shown in FIG. 10A, a part of the ultrasonic beam U emitted from the transmission probe 110 (FIG. 1) is blocked by the defect portion D, but the direct wave U3 not blocked by the defect portion D is coaxial. It is incident on the arrangement receive probe 140. On the other hand, as shown in FIG. 10B, the scattered wave U1 scattered by the defect portion D is incident on the eccentric arrangement receiving probe 120. As shown in FIG. 10B, the scattered wave U1 has a different propagation path from the ultrasonic beam U incident on the coaxially arranged receiving probe 140, so that the phase of the wave is different. In addition, the phase of the wave changes even in the process of being scattered by the defect portion D.

As described above, the ultrasonic waves received by the coaxially arranged receiving probe 140 and the ultrasonic waves received by the eccentric arrangement receiving probe 120 have different wave phases. Therefore, when the two received signals are properly combined, they cancel each other out. The appropriate synthesis referred to here is a synthesis that reflects the phase, and for example, there is a synthesis that is Fourier transformed in the frequency domain, and among them, signal synthesis in the time domain is preferable. That is, it is preferable that the interference signal generation unit 231 performs signal synthesis in the time domain. It can be easily synthesized by synthesizing in the time domain.

FIG. 26A is a diagram showing changes in the received signal A received by the coaxially arranged reception probe 140 at the measurement point. FIG. 26B is a diagram showing changes in the received signal B received by the eccentric arrangement receiving probe 120 at the measurement point. FIG. 26C is a diagram showing changes at the measurement points of the interference signal C synthesized by the interference signal generation unit 231. In these figures, the horizontal axis is the x-coordinate of the measurement position, the vertical axis is the maximum value of the amplitude, and the defect portion D exists at the position of x = 0.

The received signal A received by the coaxially arranged reception probe 140 (FIG. 10A) decreases at the position of the defective portion D (x = 0; the same applies hereinafter). Since the received signal B received by the eccentric arrangement receiving probe 120 (FIG. 10B) corresponds to the scattered wave U1, it increases at the position of the defective portion D. The interference signal C, which is a combination of the two, is significantly reduced as compared with the reception signal A alone due to the interference effect between the reception signal A and the reception signal B whose phases are different at the position of the defect portion D. Therefore, the received signal B of the scattered wave U1 increases at the position of the defect portion D (FIG. 26B), but the interference signal C output from the interference signal generation unit 231 decreases at the position of the defect portion D (FIG. 26C). .. The degree of reduction is larger than that of the received signal A (FIG. 26A) of the coaxially arranged reception probe 140.

In this way, by synthesizing the received signal of the coaxially arranged reception probe 140 and the received signal of the eccentric arrangement receiving probe 120 by the interference signal generation unit 231, the amount of signal change caused by the defect unit D can be increased, and the detection performance can be increased. In particular, the detection sensitivity can be improved.

Returning to FIG. 25, the output signal of the reception system 220a and the output signal of the reception system 220b are further input to the scattered wave feature amount extraction unit 232a and the direct wave feature amount extraction unit 232b, respectively. The scattered wave feature amount extraction unit 232a extracts the feature amount derived from the defect portion D from the signal waveform of the scattered wave U1. The direct wave feature amount extraction unit 232b extracts the feature amount derived from the defect portion D from the signal waveform of the direct wave U3. The feature amount extraction is, for example, extraction of the maximum value of the signal amplitude in an appropriate delay time range in consideration of the signal delay time, feature amount extraction in the frequency domain such as short-time Fourier transform and wavelet transform, and the like.

Further, the output signal of the interference signal generation unit 231 is input to the interference signal feature amount extraction unit 232c. The interference signal feature amount extraction unit 232c extracts the feature amount derived from the defect portion D from the waveform of the generated interference signal in the same manner as the scattered wave feature amount extraction unit 232a and the direct wave feature amount extraction unit 232b.

The output signals (extracted feature amounts) obtained by the scattered wave feature amount extraction unit 232a, the direct wave feature amount extraction unit 232b, and the interference signal feature amount extraction unit 232c are input to the signal integration processing unit 240. The signal integration processing unit 240 determines that the defect unit D exists at the position where the feature amount is extracted. The signal integration processing unit 240 outputs the position where it is determined that the defect unit D exists to the data processing unit 201.

According to the defect information determination unit 205, it is possible to detect from a large defect portion D to a minute defect portion D, and the detection accuracy can be improved.

The scattered wave feature amount extraction unit 232a, the direct wave feature amount extraction unit 232b, and the interference signal feature amount extraction unit 232c may be output to the data processing unit 201 without going through the signal integration processing unit 240. With such a configuration, it is possible to visualize a plurality of types of defect images based on the three types of information, so that more information regarding the defect portion D can be obtained.

FIG. 27 is a diagram showing the configuration of the ultrasonic inspection device Z according to the tenth embodiment. In the tenth embodiment, the focal length R3 of the coaxially arranged receiving probe 140 is shorter than the focal length R2 of the eccentric arrangement receiving probe 120. As a result, the convergence of the coaxially arranged receiving probe 140 is higher than that of the eccentric arrangement receiving probe 120.

By making the focal length R3 of the coaxially arranged receiving probe 140 shorter than the focal length R2 of the eccentric arrangement receiving probe 120, among the ultrasonic beams U emitted from the transmitting probe 110, the ultrasonic beam U on the receiving sound axis AX2 Can be efficiently received by the coaxially arranged receiving probe 140. On the other hand, since the scattered wave U1 has a plurality of propagation paths, the eccentric arrangement receiving probe 120 that receives the scattered wave U1 can sufficiently receive the scattered wave U1 by lowering the convergence. Therefore, defects can be detected more efficiently by using the receiving probe 121 having convergence according to the characteristics of the direct wave U3 and the scattered wave U1.

FIG. 28 is a diagram showing the configuration of the ultrasonic inspection device Z according to the eleventh embodiment. In the eleventh embodiment, an array type probe 122 having the functions of both the eccentric arrangement receiving probe 120 and the coaxial arrangement receiving probe 140 is used. The array-type probe 122 is a receiving probe in which a plurality of sound sensing elements 122a (also functioning as a unit probe 120a (FIG. 18)) are arranged one-dimensionally (FIG. 28) or two-dimensionally (FIG. 29 below). 121.

The array type probe 122 arranges the received sound axis AX2 of one constituent sound sensing element 122a so as to coincide with the transmission sound axis AX1. The sound sensing element 122a arranged at this position functions as a coaxially arranged receiving probe 140. Similar to the example shown in FIG. 18, the remaining sound sensing elements 122a are arranged continuously and symmetrically in the left-right direction of the paper in FIG. 28 centered on the transmission sound axis AX1, and these are arranged as eccentric arrangement receiving probes 120. Function. In this example, the sound sensing element 122a is arranged one-dimensionally.

By using the array type probe 122 and arranging the sound sensing elements 122a one-dimensionally, the installation cost of the array type probe 122 can be reduced because the number of installed sound sensing elements 122a is small, and a plurality of sound sensing elements can be installed. The scattered wave U1 can be received at 122a. Further, even when the defect D is small and the ultrasonic wave propagation is completely blocked, the sound sensing element 122a having the reception sound axis AX2 corresponding to the transmission sound axis AX1 can detect the decrease in the signal amount. As a result, it is possible to efficiently detect from a small defect portion D to a large defect portion D.

FIG. 29 is a diagram showing the configuration of the ultrasonic inspection device Z according to the twelfth embodiment. FIG. 29 is a plan view of the transmission probe 110 and the array-type probe 122 as viewed from the minus side of the z-axis of FIG. 1, that is, the side of the array-type probe 122. In FIG. 28 above, the sound sensing elements 122a constituting the array type probe 122 are arranged one-dimensionally only in one direction. However, in the array type probe 122 shown in FIG. 29, the sound sensing element 122a is two-dimensionally arranged in two directions of xy. In the illustrated example, the sound sensing elements 122a are arranged in the same number (seven pieces) in each direction of xy, and are arranged in a square shape. However, the sound sensing element 122a is not limited to the square arrangement, and may be arranged in each shape such as a rectangle, a circle, and an ellipse.

By using the array type probe 122 and arranging the sound sensing elements 122a two-dimensionally, the scattered wave U1 can be received by many sound sensing elements 122a and the detection omission of the scattered wave U1 can be suppressed. Further, even when the defective portion D is small and the ultrasonic wave propagation is completely blocked, the sound sensing element 122a having the received sound axis AX2 corresponding to the transmitted sound axis AX1 can detect the decrease in the signal amount. As a result, it is possible to efficiently detect from a small defect portion D to a large defect portion D.

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

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

Further, each of the above-mentioned configurations, functions, and each part constituting the block diagram may be realized by hardware, for example, by designing a part or all of them by an integrated circuit or the like. Further, as shown in FIG. 22, each configuration, function, etc. described above may be realized by software by interpreting and executing a program in which a processor such as a CPU 252 realizes each function. In addition to storing information such as programs, tables, and files that realize each function in HD, memory 251 and recording devices such as SSD (Solid State Drive), IC (Integrated Circuit) cards, and SD ( It can be stored in a recording medium such as a Secure Digital) card or a DVD (Digital Versaille Disc).

Further, in each embodiment, the control lines and information lines are shown as necessary for explanation, and not all the control lines and information lines are shown in the product. In practice, you can think of almost all configurations as interconnected.

1 Scanning measuring device 101 Housing 102 Sample stand 103 Transmission probe scanning unit 104 Reception probe scanning unit 105 Eccentric distance adjustment unit 106 Installation angle adjustment unit 110 Transmission probe 111 Oscillator 112 Backing 113 Matching layer 114 Detector surface 115 Transmission probe housing Body 116 Connector 117, 118 Lead wire 120 Eccentric arrangement Receive probe (receive probe)
120a Unit probe 121 Receive probe 122 Array type probe (transmit probe, receive probe)
122a Sound sensor 140 Coaxially arranged receive probe (receive probe)
2 Control device 201 Data processing unit 202 Drive unit 203 Position measurement unit 204 Scan controller 205 Defect information determination unit 210 Transmission system 211 Waveform generator 212 Output amplifier 220, 220a, 220b, 220c Reception system 221 Waveform analysis unit 222 Signal amplifier 231 Interference Signal generation unit 232a Scattered wave feature amount extraction unit 232b Direct wave feature amount extraction unit 232c Interference signal feature amount extraction unit 240 Signal integration processing unit A, B Received signal AX1 Transmission sound axis AX2 Received sound axis C Interference signal D Defect part
E Subject L Eccentric distance N Sound part P Detector R1, R2, R3 Focal length S101 Emission step S102 Reception step S103 Analysis step S104 Judgment step S105 Notification step T1, T2 Beam incident area U, U2 Ultrasonic beam U1 Scattering Wave U3 Direct wave Z Ultrasonic inspection device

Claims (20)

It is an ultrasonic inspection device that inspects the inspected object by injecting an ultrasonic beam into the inspected object through a gas.
It is provided with a scanning measurement device that scans and measures the ultrasonic beam on the object to be inspected, and a control device that controls the drive of the scanning measurement device.
The scanning measuring device is
The transmission probe that emits the ultrasonic beam and
The object to be inspected is provided with an eccentric arrangement receiving probe installed on the opposite side of the transmitting probe to receive the ultrasonic beam.
An ultrasonic inspection apparatus in which the eccentric arrangement receiving probe is arranged so that the eccentric distance between the transmission sound axis of the transmission probe and the reception sound axis of the eccentric arrangement receiving probe is larger than zero. The ultrasonic inspection apparatus according to claim 1, wherein the eccentric distance is set to a distance at which a scattered wave generated by scattering of the ultrasonic beam at a defective portion of the inspected object can be received. The eccentric distance is set so that the received signal strength of the eccentric arrangement receiving probe when incident on the defective portion of the inspected object is larger than the received signal intensity when incident on the healthy portion of the inspected object. The ultrasonic inspection apparatus according to claim 1, wherein the ultrasonic inspection apparatus is set. The ultrasonic inspection apparatus according to claim 1, wherein the eccentric distance is set to a distance at which a received signal other than noise is not detected when the sound portion of the inspected object is irradiated. The ultrasonic inspection apparatus according to claim 1, further comprising an eccentric distance adjusting unit that adjusts the position of at least one of the transmitting probe and the eccentric arrangement receiving probe. The ultrasonic inspection apparatus according to claim 1, wherein the focal length of the eccentric arrangement receiving probe is longer than the focal length of the transmitting probe. The ultrasonic inspection apparatus according to claim 1, wherein the focal point of the eccentric arrangement receiving probe is closer to the transmitting probe than the focal point of the transmitting probe. The ultrasonic inspection apparatus according to claim 1, wherein the beam incident area of the eccentric arrangement receiving probe in the inspected body is larger than the beam incident area of the transmitting probe in the inspected body. The scanning measuring device includes an installation angle adjusting unit that adjusts the inclination of the eccentric arrangement receiving probe so that the angle θ formed by the transmitting sound axis and the receiving sound axis satisfies 0 ° <θ <90 °. The ultrasonic inspection apparatus according to claim 1. The ultrasonic inspection apparatus according to claim 1, wherein the eccentric arrangement receiving probe includes a plurality of unit probes. The control device is based on the reception signal of the unit probe that has received the scattered wave generated by the scattering of the irradiated ultrasonic beam in the defective portion of the inspected object among the plurality of unit probes. The ultrasonic inspection apparatus according to claim 10, further comprising a defect information determination unit for determining information regarding a defect portion in an inspected object. The ultrasonic inspection apparatus according to claim 10, wherein the plurality of unit probes are arranged radially around the transmission sound axis. The ultrasonic inspection apparatus according to claim 10, wherein at least two of the unit probes are arranged at positions having the same eccentric distance. The length of the oscillator of the eccentric arrangement receiving probe in the eccentric direction with respect to the transmitting sound axis is longer than the length in the direction along the surface of the inspected object and in the direction orthogonal to the eccentric direction. The ultrasonic inspection apparatus according to claim 1. The ultrasonic inspection device according to claim 1 or 10, wherein the scanning measuring device includes a coaxially arranged receiving probe arranged at a position where the eccentricity distance is zero. The ultrasonic inspection apparatus according to claim 15, wherein the focal length of the coaxially arranged receiving probe is shorter than the focal length of the eccentrically arranged receiving probe. The ultrasonic inspection device according to claim 15, wherein the control device includes an interference signal generation unit that synthesizes an output signal of the eccentric arrangement receiving probe and an output signal of the coaxial arrangement receiving probe. The ultrasonic inspection apparatus according to claim 17, wherein the interference signal generation unit performs signal synthesis in a time domain. An ultrasonic inspection method for inspecting an inspected object by injecting an ultrasonic beam into the inspected object via a gas.
The emission step, which emits an ultrasonic beam from the transmission probe,
A receiving step of receiving the ultrasonic beam in an eccentric arrangement receiving probe which is installed on the opposite side of the transmitting probe with respect to the inspected object and has a receiving sound axis at a position different from the transmitting sound axis of the transmitting probe.
An analysis step for generating signal intensity data based on the received ultrasonic beam signal, and
An ultrasonic inspection method comprising. It is characterized by including a determination step of determining the presence or absence of a defective portion of the inspected object by determining whether or not the signal strength data generated in the analysis step is equal to or higher than a preset threshold value. The ultrasonic inspection method according to claim 19.

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