Ultrasonic examination apparatus and method

Abstract

Provided is an ultrasonic inspection apparatus having excellent detection performance of a defect portion, such as resolution of a display image. To this end, the ultrasonic inspection apparatus Z includes a scan measurement apparatus 1 that performs scanning and measurement of an ultrasonic beam on an object to be inspected, and a control apparatus 2 that controls driving of the scan measurement apparatus 1. The scan measurement apparatus 1 includes a transmission probe 110 that transmits an ultrasonic beam, and an eccentrically arranged reception probe 120 that receives an ultrasonic beam. The eccentrically arranged reception probe 120 is arranged so that an eccentric distance between a transmission sound axis of the transmission probe 110 and a reception sound axis of the eccentrically arranged reception probe 120 is greater than zero. The control apparatus 2 includes a phase extraction section 231 that extracts phase information of a signal of an ultrasonic beam received by the eccentrically arranged reception probe 120, and a phase change amount calculation section 232 that calculates a phase change amount of the extracted phase information with respect to a scan position.

Description

Technical Field

[0001] This disclosure relates to an ultrasonic inspection device and an ultrasonic inspection method. Background Technology

[0002] Methods for inspecting defects in an object using ultrasonic beams are known. For example, when a defect (cavity, etc.) with low acoustic impedance, such as air, exists inside the object, the transmission of the ultrasonic beam decreases because a gap with low acoustic impedance is created inside the object. Therefore, defects inside the object can be detected by measuring the transmission of the ultrasonic beam.

[0003] Regarding ultrasonic inspection devices, the technology described in Patent Document 1 is known. In the ultrasonic inspection device described in Patent Document 1, a rectangular wave burst signal containing a specific number of consecutive negative rectangular waves is applied to a transmitting ultrasonic probe disposed opposite to the subject in the air. A receiving ultrasonic probe disposed opposite to the subject in the air converts the ultrasonic waves propagating in the subject into a transmitted wave signal. The presence or absence of defects in the subject is determined based on the signal level of the transmitted wave signal. In addition, the acoustic impedance of the transmitting and receiving ultrasonic probes, including the transducer and the front panel mounted on the transducer side of the transducer, is set lower than that of a contact ultrasonic probe used in contact with the subject.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-128965 (especially the abstract) Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In the ultrasonic inspection apparatus described in Patent Document 1, when observing minute defects in the inspected object, there is a problem of reduced resolution of the observed defect image. Specifically, the image outline corresponding to the defect becomes blurred. This is because when a portion of the ultrasonic beam is blocked by the defect, the received signal also changes. This problem is particularly pronounced when the size of the defect to be detected is the same as or smaller than the size (beam diameter) of the ultrasonic beam.

[0009] The problem this disclosure aims to solve is to provide an ultrasonic inspection apparatus and method with excellent defect detection performance, such as high resolution for displaying images.

[0010] Technical means to solve the problem

[0011] The ultrasonic inspection apparatus disclosed herein relates to an ultrasonic inspection device that inspects an object by incident an ultrasonic beam onto the object via a fluid. This ultrasonic inspection device comprises: a scanning and measuring device for scanning and measuring the ultrasonic beam on the object; and a control device for controlling the driving of the scanning and measuring device. The scanning and measuring device includes a transmitting probe for emitting the ultrasonic beam and an off-center receiving probe, wherein the off-center receiving probe is configured such that the off-center distance between the transmitting tone axis of the transmitting probe and the receiving tone axis of the off-center receiving probe is greater than zero.

[0012] The control device includes: a phase extraction unit for extracting phase information of the signal from the ultrasonic beam received by the eccentrically positioned receiving probe; and a phase change calculation unit for calculating the change in the extracted phase information at each scanning position. Other solutions will be described later in the embodiments.

[0013] Invention Effects

[0014] According to this disclosure, an ultrasonic inspection apparatus and ultrasonic inspection method with excellent defect detection performance, such as excellent image resolution, can be provided. Attached Figure Description

[0015] Figure 1 This is a diagram showing the structure of the ultrasonic inspection device according to the first embodiment.

[0016] Figure 2A It is a diagram illustrating the transmitting tone shaft, the receiving tone shaft, and the eccentricity, and it shows the situation where the transmitting tone shaft and the receiving tone shaft extend in the vertical direction.

[0017] Figure 2B It is a diagram illustrating the transmitting tone shaft, the receiving tone shaft, and the eccentricity distance, and it shows the case where the transmitting tone shaft and the receiving tone shaft are tilted and extended.

[0018] Figure 3 This is a cross-sectional schematic diagram showing the structure of the transmitting probe.

[0019] Figure 4A It is a received waveform from the eccentrically configured receiving probe, and is a diagram showing the received waveform at the healthy part N of the inspected object E.

[0020] Figure 4B It is a received waveform from the eccentrically configured receiving probe, and is a diagram showing the received waveform at the defective part D of the inspected object E.

[0021] Figure 5 This is an example diagram showing a plot of signal strength data.

[0022] Figure 6AThis is the propagation path of the ultrasonic beam in this embodiment, and it is a diagram showing the case where the ultrasonic beam is incident on the healthy part.

[0023] Figure 6B This is the propagation path of the ultrasonic beam in this embodiment, and it is a diagram showing the case where the ultrasonic beam is incident on the defect.

[0024] Figure 7A It is a diagram showing the propagation path of the ultrasonic beam under existing ultrasonic examination methods, and it is a diagram showing the incident on a healthy part.

[0025] Figure 7B It is a diagram showing the propagation path of the ultrasonic beam under existing ultrasonic inspection methods, and it is also a diagram showing the incident on the defect.

[0026] Figure 8 It is a graph representing the signal strength data under existing ultrasound examination methods.

[0027] Figure 9A It is a diagram showing the interaction between the defect in the body being inspected and the ultrasonic beam, and also a diagram showing the case of receiving a direct ultrasonic beam.

[0028] Figure 9B It is a diagram showing the interaction between the defect in the body being inspected and the ultrasonic beam, and also a diagram showing the situation of receiving scattered waves.

[0029] Figure 10 This is a functional block diagram of the control device.

[0030] Figure 11 This is a diagram schematically showing the changes in the received signal of an eccentrically configured receiving probe at each scanning position along the x-axis.

[0031] Figure 12A This is a diagram showing the scanning position where the ultrasonic beam did not strike the defect.

[0032] Figure 12B This diagram shows the scanning position where the ultrasonic beam is incident on the defect, but the transmitting sound axis does not enter the defect.

[0033] Figure 12C This is a diagram showing the scanning position where the ultrasonic beam is incident on the defect and the transmitting shaft enters the defect.

[0034] Figure 13 It is a diagram showing the hardware structure of the control device.

[0035] Figure 14 This is a flowchart illustrating the ultrasonic examination method of the first embodiment.

[0036] Figure 15This is a diagram showing the structure of the ultrasonic inspection device according to the second embodiment.

[0037] Figure 16 This is a functional block diagram illustrating the ultrasonic inspection device of the second embodiment.

[0038] Figure 17 This is a diagram showing the structure of the ultrasonic inspection device according to the third embodiment.

[0039] Figure 18 This is a diagram showing the structure of the ultrasonic inspection device according to the fourth embodiment.

[0040] Figure 19 This is a diagram showing the structure of the ultrasonic inspection device in the fifth embodiment.

[0041] Figure 20 This is a functional block diagram illustrating the ultrasonic inspection device in the fifth embodiment.

[0042] Figure 21 This is a diagram showing the relationship between the transmitting probe and the eccentrically configured receiving probe of the ultrasonic inspection apparatus according to the sixth embodiment.

[0043] Figure 22 This is a diagram illustrating the relationship between the beam incident area of ​​the transmitting probe and the beam incident area of ​​the eccentrically configured receiving probe.

[0044] Figure 23 This is a diagram illustrating an example of an eccentrically configured receiving probe according to the seventh embodiment.

[0045] Figure 24 This is a diagram showing the structure of the scanning measurement device of the ultrasonic inspection apparatus according to the eighth embodiment.

[0046] Figure 25 This diagram illustrates the reason for the effects of the eighth embodiment.

[0047] Figure 26 This is a diagram showing the structure of the ultrasonic inspection device according to the 9th embodiment.

[0048] Figure 27 This is a functional block diagram of the ultrasonic inspection device according to the 9th embodiment.

[0049] Figure 28 This is a diagram showing the configuration of the eccentrically positioned receiving probe in the tenth embodiment.

[0050] Figure 29 This is a diagram showing the configuration of the eccentrically arranged receiving probes in the 11th embodiment, and a diagram showing the tilted arrangement of the unit probes.

[0051] Figure 30This is a diagram showing the configuration of the eccentrically configured receiving probe in the 11th embodiment, and it is a diagram showing the configuration of a unit probe in the vertical direction.

[0052] Figure 31 This is a diagram showing the structure of the ultrasonic inspection device according to the 12th embodiment.

[0053] Figure 32 This is a diagram showing the structure of the ultrasonic inspection device according to the 13th embodiment.

[0054] Figure 33 This is a diagram showing the structure of the ultrasonic inspection device according to the 14th embodiment. Detailed Implementation

[0055] Hereinafter, with reference to the accompanying drawings, methods for implementing this disclosure (referred to as embodiments) will be described. However, this disclosure is not limited to the following embodiments; for example, different embodiments can be combined with each other, or varied arbitrarily within the scope of not significantly impairing the effects of this disclosure. Furthermore, the same symbols are used to label the same components, and repeated descriptions are omitted. Moreover, those with the same function are labeled with the same name. The illustrations are merely illustrative; for the sake of clarity, the actual structure may sometimes be modified within the scope of not significantly impairing the effects of this disclosure.

[0056] (First Embodiment)

[0057] Figure 1 This is a diagram showing the structure of the ultrasonic inspection device Z according to the first embodiment. Figure 1 In the diagram, the scanning measuring device 1 is shown in a cross-sectional view. Figure 1 In the figure, represents an orthogonal three-axis coordinate system including the x-axis (left-right direction of the paper), the y-axis (orthogonal direction of the paper), and the z-axis (up-down direction of the paper).

[0058] The ultrasonic inspection device Z transmits an ultrasonic beam U to the object being inspected E via a fluid F. Figure 3 The apparatus for inspecting the object E. The fluid F is, for example, a liquid W such as water. Figure 17 The object being inspected, E, exists in a fluid F, which is a gas G such as air. In the first embodiment, air (an example of gas G) is used as the fluid F. Therefore, the interior of the housing 101 of the scanning measuring device 1 becomes a cavity filled with air. Figure 1 As shown, the ultrasonic inspection device Z includes a scanning and measuring device 1, a control device 2, and a display device 3. The display device 3 is connected to the control device 2.

[0059] The scanning measurement device 1 is a device for scanning and measuring the object E with an ultrasonic beam U. It includes a sample stage 102 fixed to a housing 101, on which the object E is placed. The object E is made of any material. For example, the object E may be a solid material, or more specifically, a metal, glass, resin, or a composite material such as CFRP (carbon-fiber reinforced plastics). Furthermore, in... Figure 1 In the example, the inspected object E has a defect D inside. The defect D is a cavity, etc. Examples of the defect D are cavities, foreign materials that are different from what should be the material, etc. In the inspected object E, the part other than the defect D is called the intact part N.

[0060] Because the defective part D and the intact part N are made of different materials, their acoustic impedances differ, causing a change in the propagation characteristics of the ultrasonic beam U. The ultrasonic inspection device Z observes this change and detects the defective part D.

[0061] The scanning measurement device 1 includes a transmitting probe 110 that emits an ultrasonic beam U and an eccentrically positioned receiving probe 120. The transmitting probe 110 is mounted on the housing 101 via a transmitting probe scanning unit 103 and emits the ultrasonic beam U. The eccentrically positioned receiving probe 120 is positioned opposite the transmitting probe 110 to the object being inspected, and is a receiving probe 121 that receives the ultrasonic beam U. The eccentrically positioned receiving probe 120 has a receiving axis AX2 at a position different from the transmitting axis AX1 of the transmitting probe 110. The distance between the transmitting axis AX1 and the receiving axis AX2 is the eccentric distance L. The eccentrically positioned receiving probe 120 is mounted on the housing 101 via a receiving probe scanning unit 104.

[0062] In addition, in this specification, the probe in the receiving probe 121 that receives the ultrasonic beam U and is positioned at an eccentric distance L greater than zero is defined as the eccentrically positioned receiving probe 120, and the probe positioned at an eccentric distance L of zero is defined as the coaxially positioned receiving probe 140. Figure 2A (etc.). In other words, receiving probe 121 is a term that includes eccentrically configured receiving probe 120 and coaxially configured receiving probe 140, and is the name of a probe that receives ultrasonic waves regardless of the eccentricity distance L.

[0063] Here, "opposite side of sending probe 110" refers to the space opposite to the space where sending probe 110 is located (opposite side in the z-axis direction) among the two spaces separated by the inspected object E. The x and y coordinates do not refer to the same opposite side (i.e., positions symmetrical with respect to the xy plane). Figure 1As shown, the transmitting probe 110 and the eccentrically configured receiving probe 120 are set up with the transmitting tone shaft AX1 and the receiving tone shaft AX2 offset by an eccentric distance L. The specific details of the transmitting tone shaft AX1, the receiving tone shaft AX2, and the eccentric distance L are described below.

[0064] By moving the receiving probe scanning section 104, the eccentrically configured receiving probe 120 scans the sample stage 102 in the x-axis and y-axis directions. The transmitting probe 110 and the eccentrically configured receiving probe 120 clamp the object under inspection E while maintaining an eccentric distance L in the x-axis or y-axis direction and scanning (thick double arrow).

[0065] Furthermore, in the scanning measurement device 1, details are described below, but the eccentricity distance L is set as follows: That is, the eccentricity distance L is set to the distance at which the scattered wave U1 generated by the scattering of the ultrasonic beam U at the defect D of the inspected object E is received. Alternatively, the eccentricity distance L is set such that the received signal intensity received by the eccentrically positioned receiving probe 120 when incident on the defect D of the inspected object E is greater than the received signal intensity when incident on the intact part N of the inspected object E. Alternatively, the eccentricity distance L is set to the distance at which no received signal other than noise is detected when irradiating the intact part N of the inspected object E.

[0066] The scanning measurement device 1 includes an eccentricity adjustment unit 105, which adjusts the position of at least one of the transmitting probe 110 or the eccentrically positioned receiving probe 120 such that the eccentricity distance L between the transmitting tone shaft AX1 and the receiving tone shaft AX2 is greater than zero. The eccentricity adjustment unit 105 (eccentricity adjustment mechanism) is provided in the receiving probe scanning unit 104 provided in the housing 101. Furthermore, the eccentrically positioned receiving probe 120 is provided in the eccentricity adjustment unit 105. The eccentrically positioned receiving probe 120 can be moved independently of the position of the receiving probe scanning unit 104 by means of the eccentricity adjustment unit 105, and can be set such that the offset between the receiving tone shaft AX2 and the transmitting tone shaft AX1 is the eccentricity distance L. Alternatively, the eccentricity adjustment unit 105 can also be provided on the transmitting probe scanning unit 103 side. That is, since it can be set by setting the offset between the receiving tone shaft AX2 and the transmitting tone shaft AX1 as the eccentric distance L, the eccentric distance adjustment unit 105 can be set on the receiving probe 121 side or on the transmitting probe 110 side.

[0067] The scanning measurement device 1 is connected to a control device 2. The control device 2 controls the drive of the scanning measurement device 1, and controls the movement (scanning) of the transmitting probe 110 and the eccentrically positioned receiving probe 120 by issuing instructions to the transmitting probe scanning unit 103 and the receiving probe scanning unit 104. By synchronously moving the transmitting probe scanning unit 103 and the receiving probe scanning unit 104 in the x-axis and y-axis directions, the transmitting probe 110 and the eccentrically positioned receiving probe 120 scan the object E to be inspected in the x-axis and y-axis directions. Furthermore, the control device 2 emits an ultrasonic beam U from the transmitting probe 110 and performs waveform analysis based on the signal obtained from the eccentrically positioned receiving probe 120.

[0068] Furthermore, in this embodiment, an example is shown where the subject E is fixed to the housing 101 via the sample stage 102, i.e., the subject E is fixed to the housing 101, and the scanning transmitting probe 110 and the eccentrically positioned receiving probe 120 are used. Alternatively, the structure could be configured such that the transmitting probe 110 and the eccentrically positioned receiving probe 120 are fixed to the housing 101, and the subject E is moved to perform the scanning.

[0069] In the illustrated example, gas G (is an example of fluid F. It could also be liquid W). Figure 17 The transducer probe 110 and the object being inspected, and the eccentrically positioned receiver probe 120 and the object being inspected, are positioned between each other. Therefore, the transducer probe 110 and the eccentrically positioned receiver probe 120 can be inspected without contact with the object being inspected, allowing for smooth and high-speed changes in their relative positions in the xy-plane. In other words, by positioning the fluid F between the transducer probe 110 and the eccentrically positioned receiver probe 120 and the object being inspected, smooth scanning can be achieved.

[0070] The transmitting probe 110 is a converging transmitting probe 110. On the other hand, the eccentrically configured receiving probe 120 uses a probe with less convergence than the transmitting probe 110. In this embodiment, the eccentrically configured receiving probe 120 uses a non-converging probe with a flat probe surface. By using this non-converging eccentrically configured receiving probe 120, information about the defect D can be collected over a wide range.

[0071] In this embodiment, relative to the transmitting probe 110, in Figure 1 The receiver probe 120 is configured with an off-center configuration by offsetting the x-axis direction by an eccentric distance L, but it can also be configured to receive the receiver probe 120. Figure 1 The receiving probe 120 is configured with an offset in the y-axis direction. Alternatively, the receiving probe 120 can be configured with an offset of L1 in the x-axis direction and L2 in the y-axis direction (i.e., the position of (L1, L2) if the position of the transmitting probe 110 in the xy plane is taken as the origin).

[0072] Figure 2AIt is a diagram illustrating the transmitting tone shaft AX1, the receiving tone shaft AX2, and the eccentricity distance L, and it shows the case where the transmitting tone shaft AX1 and the receiving tone shaft AX2 extend in the vertical direction. Figure 2B It is a diagram illustrating the transmitting tone shaft AX1, the receiving tone shaft AX2, and the eccentric distance L, and it shows the case where the transmitting tone shaft AX1 and the receiving tone shaft AX2 are extended at an angle.

[0073] The tone axis is defined as the central axis of the ultrasonic beam U. Here, the transmitting tone axis AX1 is defined as the tone axis of the propagation path of the ultrasonic beam U emitted by the transmitting probe 110. In other words, the transmitting tone axis AX1 is the central axis of the propagation path of the ultrasonic probe U emitted by the transmitting probe 110. The transmitting tone axis AX1 is as follows: Figure 2B As shown, refraction occurs at the interface containing the inspected object E. That is, as... Figure 2B As shown, when the ultrasonic beam U emitted from the transmitting probe 110 is refracted at the interface of the object being inspected E, the center (tone axis) of the propagation path of the ultrasonic beam U becomes the transmitting tone axis AX1.

[0074] Furthermore, the receiving tone axis AX2 is defined as the tone axis of the propagation path of the virtual ultrasonic beam when the receiving probe 120 is configured with an off-center orientation to emit the ultrasonic beam U. In other words, the receiving tone axis AX2 is the central axis of the virtual ultrasonic beam when the receiving probe 120 is configured with an off-center orientation to emit the ultrasonic beam U.

[0075] As a specific example, we describe the case of a non-converging receiving probe with a planar probe surface. In this case, the direction of the receiving tone axis AX2 is the normal direction of the probe surface, and the axis passing through the center point of the probe surface is the receiving tone axis AX2. When the probe surface is rectangular, its center point is defined as the intersection of the diagonals of the rectangle.

[0076] The reason why the direction of the receiving tone axis AX2 is the normal direction of the probe surface is that the virtual ultrasonic beam U emitted from the receiving probe 121 is emitted in the normal direction of the probe surface. When receiving the ultrasonic beam U, it is also possible to receive the ultrasonic beam U incident in the normal direction of the probe surface with good sensitivity.

[0077] The eccentricity distance L is defined as the offset distance between the transmitting tone axis AX1 and the receiving tone axis AX2. Therefore, as... Figure 2B As shown, when the ultrasonic beam U emitted from the transmitting probe 110 is refracted, the offset distance L is defined as the distance between the refracted transmitting sound axis AX1 and the receiving sound axis AX2. The ultrasonic inspection device Z of this embodiment uses the offset distance L defined in this way to make it greater than zero, via the offset distance adjustment unit 105 (…). Figure 1 Adjust the transmitting probe 110 and eccentrically configure the receiving probe 120. This reduces the amount of defect D emitted and transmitted from the transmitting probe 110. Figure 1 The surrounding ultrasonic beam U ( Figure 3 It is easy to use the receiving probe 121 to detect signal changes originating from the defect D.

[0078] However, in this embodiment, as a preferred example, as described above, the eccentrically configured receiving probe 120 receives the scattered wave U1 generated by the scattering of the ultrasonic beam U at the defect D. Figure 6B Since the presence of the defect D generates a scattered wave U1, the detection accuracy of the defect D can be further improved by detecting the scattered wave U1. In the following example, for the sake of simplicity, an eccentrically positioned receiving probe 120 located at a position that can receive the scattered wave U1 will be used as an example to illustrate this embodiment.

[0079] Figure 2A This indicates the case where the probe 110 is positioned in the normal direction of the surface of the object being inspected, E. Figure 2A and Figure 2B In the diagram, a solid arrow indicates the transmitting tone shaft AX1. A dashed arrow indicates the receiving tone shaft AX2. Additionally, Figure 2A and Figure 2B In the diagram, the position of the receiving probe 121 shown by the dashed line is where the eccentricity distance L is zero. The receiving probe 121, whose transmitting tone axis AX1 and receiving tone axis AX2 are aligned, is a coaxial receiving probe 140. Conversely, the receiving probe 121 shown by the solid line is an eccentrically configured receiving probe 120 positioned at an eccentricity distance L greater than zero. With the transmitting tone axis AX1 relative to the horizontal plane (… Figure 1 When the transmitting probe 110 is set perpendicular to the xy plane, the propagation path of the ultrasonic beam U is not refracted. That is, the transmitting tone axis AX1 is not refracted.

[0080] Figure 2B This diagram illustrates the configuration of the probe 110 at an angle α from the normal direction of the surface of the object being inspected, E. Figure 2B Also with Figure 2A Similarly, a solid arrow indicates the transmitting tone shaft AX1, and a single-dot dashed arrow indicates the receiving tone shaft AX2. Figure 2B In the example shown, as described above, at the interface between the object being inspected E and the fluid F, the propagation path of the ultrasonic beam U is refracted at a refraction angle β. Therefore, the transmitting tone axis AX1 is as follows: Figure 2B The solid arrow indicates a bend (refraction). In this case, since the position of the coaxial receiving probe 140 (shown by the dashed line) is on the transmitting tone axis AX1, it is a position where the eccentricity distance L is zero. Furthermore, as described above, when the ultrasonic beam U is refracted, the eccentrically configured receiving probe 120 is also configured such that the distance between the transmitting tone axis AX1 and the receiving tone axis AX2 is L. Additionally, in Figure 1In the example shown, since the transmitting probe 110 is positioned in the normal direction of the surface of the object being inspected E, the eccentricity distance L becomes as follows: Figure 2A As shown.

[0081] The eccentricity distance L is set at a position where the signal strength at the defective part D is greater than the received signal at the healthy part N of the inspected object E. This point will be described below.

[0082] Figure 3 This is a cross-sectional schematic diagram showing the structure of the transmitting probe 110. Figure 3 For simplicity, only the outline of the emitted ultrasonic beam U is shown in the diagram. In reality, a large number of ultrasonic beams U are emitted throughout the entire area of ​​the probe surface 114 in the direction of the normal vector of the probe surface 114.

[0083] The transmitting probe 110 is configured to converge an ultrasonic beam U. This allows for high-precision detection of minute defects D in the inspected object E. The reason for detecting minute defects D is explained below. The transmitting probe 110 includes a transmitting probe housing 115, inside which are a backing 112, a transducer 111, and a mating layer 113. Electrodes (not shown) are mounted on the transducer 111, and the electrodes are connected to a connector 116 via leads 118. Furthermore, the connector 116 is connected to a power supply device (not shown) and a control device 2 via leads 117.

[0084] In this specification, the probe surface 114 of the transmitting probe 110 or the receiving probe 121 is defined as the surface of the matching layer 113 when the matching layer 113 is present, and as the surface of the oscillator 111 when the matching layer 113 is not present. That is, when the probe is the transmitting probe 110, the probe surface 114 is the surface that transmits the ultrasonic beam U, and when the probe is the receiving probe 121, the probe surface is the surface that receives the ultrasonic beam U.

[0085] Figure 4A It is a received waveform from the eccentrically configured receiving probe 120, and is a diagram showing the received waveform at the healthy part N of the inspected object E. Figure 4B It is a received waveform from the eccentrically configured receiving probe 120, and is a diagram showing the received waveform at the defective part D of the inspected object E. Figure 4B This indicates the received signal when the transmitting probe 110 is positioned at the xy coordinates of a 2mm wide cavity (defect D) within the inspected object E. Additionally, in Figure 4A and Figure 4B In the figure, time represents the elapsed time after the burst wave is applied to the transmitting probe 110, and a 2mm thick stainless steel plate is used as the object under inspection, E. A burst wave with a frequency of 800kHz is applied to the transmitting probe 110. More specifically, a burst wave consisting of 10 sine waves is applied to the object under inspection, E, at a certain period.

[0086] exist Figure 4A No obvious signal was observed in the middle, but Figure 4B In the experiment, a noticeable signal was observed 90 microseconds after the burst wave was applied to the transmitting probe 110. The 90-microsecond delay until this noticeable signal was observed is due to the time required for the transmitted ultrasonic beam U to reach the scattered wave U1 and then to the eccentrically positioned receiving probe 120. Specifically, the speed of sound in air is 340 m / s, while in stainless steel, which constitutes the inspected object E, it is approximately 6000 m / s, hence the 90-microsecond delay.

[0087] Figure 5 This is a diagram illustrating an example of signal strength data plotting. In this example, the transmitting probe 110 and the eccentrically positioned receiving probe 120 scan a defect D with a width of 2 mm along the x-axis, and the received signal at the x-axis position is plotted. Figure 4B The received signal (shown) is extracted as signal strength data (signal amplitude at each scan position). In this embodiment, the signal strength data is extracted by extracting... Figure 4B The peak-to-peak value of the received signal, as shown, is the difference between the maximum and minimum values ​​within a suitable time range. As another example of a method for extracting signal strength data, it can also be... Figure 4B The received signal is converted into frequency components through signal processing such as short-time Fourier transform, and the intensity of an appropriate frequency component is extracted. Furthermore, as signal strength data, a correlation function can be calculated based on an appropriate reference wave. In this way, signal strength data is obtained at each scanning position of the transmitting probe 110.

[0088] exist Figure 5 In the plot of the signal strength data shown, the 2mm wide cavity (defect D) and Figure 5 The symbol D1 corresponds to this. It can be seen that the signal in the healthy part N of the inspected object E (the part other than the symbol D1) is of the noise level. In contrast, the received signal is significantly larger at the location of the defective part D (symbol D1).

[0089] Therefore, it is preferable that the eccentricity adjustment unit 105 adjusts the eccentricity distance L such that the received signal strength received by the eccentrically positioned receiving probe 120 when incident on the defective part D is greater than the received signal strength when incident on the intact part N. Thus, the defective part D can be detected based on the received signal strength. This eccentricity distance L is, for example, positioned to receive scattered waves U1 (… Figure 6B The eccentric configuration of the receiving tone axis AX2 of the receiving probe 120 and the transmitting tone axis AX1 of the transmitting probe 110 is used to adjust the distance between them. The eccentric distance adjustment unit 105 is not shown in the figure, but it is composed of an actuator, a motor, etc.

[0090] Furthermore, it is preferable that the eccentricity adjustment unit 105 adjusts the eccentricity distance L to a distance at which no received signal other than noise is detected when irradiating the intact part N. That is, it is preferable that the eccentricity distance adjustment unit 105 sets the eccentricity distance L so that no obvious received signal is emitted in the intact part N of the inspected object E. As a result, the SN ratio can be increased, and the location where a received signal other than noise is detected can be identified as a defect part D, and the defect part D can be detected.

[0091] The eccentricity L can be determined, for example, using a standard specimen made of the same material as the object being inspected E, and having an internal defect D. Furthermore, an ultrasonic beam U can be irradiated onto the defect D of the standard specimen, and the eccentricity L can be determined based on the position where the ultrasonic beam U or the scattered wave U1 can be received.

[0092] When the transmitting probe 110 scans only in one dimension along the x-axis, the display device 3 shows... Figure 5 The signal strength data is shown as a graph. Regarding the two-dimensional case where the scanning direction of the transmitting probe 110 is the x-axis and y-axis, the position of the defect D is represented as a 2D image by plotting the signal strength data and displayed on the display device 3.

[0093] Figure 6A This is the propagation path of the ultrasonic beam U in this embodiment, and it is a diagram showing when the ultrasonic beam U is incident on the healthy part N. Figure 6B This is the propagation path of the ultrasonic beam U in this embodiment, and it is a diagram showing when the ultrasonic beam U is incident on the defect portion D.

[0094] like Figure 6A and Figure 6B As shown, the ultrasonic beam U emitted from the transmitting probe 110 is incident on the object being inspected, E. Figure 6A As shown, when an ultrasonic beam U is incident on the intact part N, the ultrasonic beam U passes through in a manner that converges towards the transmitting sound axis AX1. Therefore, in the eccentrically configured receiving probe 120, which maintains an eccentric distance L, no received signal is observed. In contrast, as Figure 6B As shown, when an ultrasonic beam U is incident on the defect D, the ultrasonic beam U is scattered within the defect D, and this scattered wave U1 is received by the eccentrically positioned receiving probe 120. Therefore, a clear received signal is observed.

[0095] Thus, the eccentrically positioned receiving probe 120 observes the scattered wave U1 caused by the defect D of the inspected object E. Therefore, the received signal at the defect D is greater than the received signal at the intact part N. That is, it is determined that a defect D exists at the location with the larger signal. Therefore, it is preferable that the eccentric distance adjustment unit 105 adjusts the eccentric distance L to a distance that can receive the scattered wave U1 generated by the irradiated ultrasonic beam U due to scattering at the defect D of the inspected object E. This allows for the detection of the unique scattered wave U1 of the defect D, improving the detection accuracy of the defect D.

[0096] The eccentricity distance L is preferably the length that prevents the reception of the ultrasonic beam U emitted from the transmitting probe 110, allowing only selective reception of the scattered wave U1. This increases the SN ratio and improves the detection performance of the defect D, particularly its detection sensitivity. Here, "higher detection sensitivity" means that smaller defects D can be detected than in previous methods. That is, the lower limit of the detectable defect size D is smaller than in existing methods.

[0097] Here, as a comparative example, existing ultrasound examination methods are explained.

[0098] Figure 7A It is a diagram showing the propagation path of the ultrasonic beam U under existing ultrasonic examination methods, and also a diagram showing the incident beam onto the healthy part N. Figure 7B This is a diagram showing the propagation path of the ultrasonic beam U in a conventional ultrasonic inspection method, and also a diagram showing the beam incident on the defect D. In conventional ultrasonic inspection methods, for example as described in Patent Document 1, the transmitting probe 110 is configured with the transmitting tone axis AX1 aligned with the receiving tone axis AX2, and the receiving probe 140 is coaxially configured as the receiving probe 121.

[0099] like Figure 7A As shown, when an ultrasonic beam U is incident on the intact portion N of the object being inspected E, the ultrasonic beam U passes through the object being inspected E and reaches the coaxially positioned receiving probe 140. Therefore, the received signal increases. On the other hand, as... Figure 7B As shown, when an ultrasonic beam U is incident on the defect D, the received signal is reduced because the defect D blocks the transmission of the ultrasonic beam U. Thus, the defect D is detected by the reduction in the received signal. This is as shown in Patent Document 1.

[0100] Here, as Figure 7A and Figure 7B As shown, the method of detecting defect D by reducing the received signal by blocking the transmission of ultrasonic beam U in defect D is referred to here as the "blocking method". On the other hand, as in this embodiment, the method of detecting the scattered wave U1 at defect D is referred to as the "scattering method".

[0101] Figure 8This is a graph representing signal intensity data under existing ultrasound examination methods. This graph is a signal intensity graph, which was created by the inventors based on... Figure 7A and Figure 7B The ultrasonic testing method shown is a blocking method, namely, a configuration in which the transmitting tone shaft AX1 and the receiving tone shaft AX2 are aligned, to inspect the ultrasonic equipment having the same characteristics as described above. Figure 5 The defect D is the same as that of the inspected object E. Figure 8 In the diagram, the part marked D1 corresponds to the defect part D.

[0102] exist Figure 8 It was confirmed that the signal decreased at the center of defect D (position 0mm), but the decrease was small. This is believed to be because more ultrasonic waves U are transmitted through defect D, which is smaller than the size of the ultrasonic beam U. Therefore, in the blocking method where the transmitting tone axis AX1 and the receiving tone axis AX2 are aligned, it is difficult to detect signal changes originating from defect D, resulting in low detection sensitivity.

[0103] In contrast, by offsetting the transmitting tone axis AX1 and the receiving tone axis AX2, the signal intensity received by the eccentrically configured receiving probe 120 can be reduced, specifically the signal of the ultrasonic beam U around the defect D, which is smaller than the size of the ultrasonic beam U. This relatively increases the reduction in signal intensity caused by the defect D, improving the detection performance of the defect D, and particularly increasing the detection sensitivity. As described above... Figure 5 As shown, the structure of the preferred scattering method according to this embodiment is similar to that using the blocking method. Figure 8 By comparing the results of the comparative example, the location of defect D can be clearly identified. That is, if the comparative example... Figure 8 The received results shown, and Figure 5 The receiving results of the method of this embodiment shown are compared, then Figure 5 The method of this embodiment shown can achieve a high SN ratio.

[0104] Therefore, regarding the reason why the scattering method of this embodiment can obtain a high SN ratio, refer to... Figure 9A and Figure 9B Please provide an explanation.

[0105] Figure 9A This diagram illustrates the interaction between the defect D within the inspected object E and the ultrasonic beam U, and specifically shows the reception of the direct ultrasonic beam U (hereinafter referred to as "direct wave U3"). The direct wave U3 will be described below. Figure 9BThis diagram illustrates the interaction between the defect D within the inspected object E and the ultrasonic beam U, specifically showing the case where the scattered wave U1 is received. Here, we examine the case where the size of the defect D is smaller than the width of the ultrasonic beam U (hereinafter referred to as the beam width BW). The beam width BW here refers to the width of the ultrasonic beam U reaching the defect D.

[0106] In addition, due to Figure 9A and Figure 9B The shape of the ultrasonic beam U in a tiny region near the defect D is schematically shown; therefore, the ultrasonic beam U is depicted in parallel, but in reality, it is a converging ultrasonic beam U. Furthermore, Figure 9A and Figure 9B The position of the receiving probe 121 is shown conceptually for ease of understanding; the position and shape of the receiving probe 121 are not accurately scaled. That is, if considered using a magnified scale of the shape of the defect D and the ultrasonic wave U, the receiving probe 121 is located relatively close to the top and bottom of the drawing. Figure 9A and Figure 9B The location shown is further away. Here, the receiving probe 121 is at... Figure 9A The middle is a coaxial receiving probe 140, in Figure 9B The center refers to the eccentric configuration of the receiving probe 120.

[0107] Even if the ultrasonic beam U is incident at a convergent point, it still has a finite width near the defect D. Let this be the beam width BW at the location of the defect D. Incidentally, in Figure 9A and Figure 9B In the figure, it indicates that the beam width BW at the location of the defect D is wider than the size of the defect D.

[0108] Figure 9A This diagram illustrates a blocking method where the transmitting tone axis AX1 and the receiving tone axis AX2 are aligned. When the defect D is smaller than the beam width BW, the received signal decreases, but does not become zero, because a portion of the ultrasonic beam U is blocked. For example, when the cross-sectional area of ​​the defect D is 20% of the beam cross-sectional area defined by the beam width BW, the received signal is limited to a reduction of approximately 20%, making it difficult to detect the defect D. That is, in cases such as... Figure 9A In the situation shown, at the location where defect D exists, the received signal is reduced by 20% (see reference). Figure 8 ).

[0109] Figure 9B This diagram illustrates the preferred method of this embodiment, namely the scattering method. In the scattering method, when the ultrasonic beam U does not reach the defect D, the ultrasonic beam U does not incident on the eccentrically positioned receiving probe 120, therefore the received signal is zero. Furthermore, as... Figure 9BAs shown, when a portion of the ultrasonic beam U illuminates the defect D, the scattered wave U1 is observed by the eccentrically positioned receiving probe 120, making it easier to detect the defect D compared to the blocking method. That is, if the defect D is absent, the received signal is zero; if the defect D is present, even if it is small, the received signal is not zero. Therefore, the signal-to-noise ratio (SN ratio) can be improved (see reference). Figure 5 ).

[0110] Thus, according to the method of this embodiment (scattering method), defects D smaller than the beam width BW can be detected with high sensitivity. Here, "can be detected with high sensitivity" means that defects D smaller than those in existing methods can be detected. That is, the lower limit of the size of the detectable defect D is smaller than that in existing methods.

[0111] In addition, such as Figure 9A As shown, in the blocking method, the defective part D is determined by the amount of the received signal corresponding to the healthy part N, based on its reduction. Therefore, it is preferable to set the received signal at the healthy part N to a fixed value. However, ultrasonic waves propagating in fluid F, especially in gas G, differ from those propagating in liquid W ( Figure 17 Compared to the ultrasonic waves propagating in the scattering method, the intensity reaching the receiving probe 121 is extremely small. Therefore, it is preferable to amplify the received signal with a high amplification rate (gain). Therefore, to maintain a fixed gain, a high-precision signal amplification circuit is preferred. On the other hand, in the scattering method of this embodiment, such as Figure 5 As shown, the signal is approximately zero in the healthy part N, but a signal is observed due to the defective part D, thus reducing the requirement for the gain stability of the signal amplification circuit. In the aforementioned... Figure 5 In this case, the signal strength value increases the offset value.

[0112] Furthermore, in this embodiment, a positive image can be obtained. That is, in the scattering method, the healthy portion N generates no signal, or even if a signal is generated, it is small, while a new signal is generated or the signal becomes larger in the defective portion D. In other words, a positive image of the defective portion D can be obtained. In contrast, in the blocking method, the signal is larger in the healthy portion N, while the signal is reduced in the defective portion D. In other words, a negative image of the defective portion D can be obtained.

[0113] Figure 10 This is a functional block diagram of the control device 2. The control device 2 includes a transmitting system 210, a receiving system 220, a data processing unit 201, a scanning controller 204, a drive unit 202, and a position measuring unit 203.

[0114] The transmitting system 210 is a system that generates an applied voltage to the transmitting probe 110. The transmitting system 210 includes a waveform generator 211 and a signal amplifier 212. A burst signal is generated in the waveform generator 211. The generated burst signal is amplified by the signal amplifier 212. The voltage output from the signal amplifier 212 is applied to the transmitting probe 110.

[0115] The receiving system 220 is a system for detecting the received signal output from the eccentrically configured receiving probe 120. The signal output from the eccentrically configured receiving probe 120 is input to the signal amplifier 222 and amplified. The amplified signal is then input to the waveform analysis unit 221. The waveform analysis unit 221 generates signal strength data from the received signal. Figure 5 The generated signal strength data is sent to the data processing unit 201.

[0116] The receiving system 220 includes a phase extraction unit 231. The output signal of the signal amplifier 222 is input to the phase extraction unit 231. The phase extraction unit 231 extracts the phase information of the ultrasonic beam U (scattered wave U1) signal received by the eccentrically positioned receiving probe 120. The extracted phase information is sent to the phase change calculation unit 232 of the data processing unit 201.

[0117] The phase of the signal is the delay time from when the ultrasonic beam U is emitted by the transmitting probe 110 until it reaches a specific position of the received signal. The specific position of the received signal refers to the location of a characteristic received signal whose delay time can be easily calculated. For example, in the case of using a burst wave of 10 waves, it is the position of the 3rd wave.

[0118] Furthermore, the delay time within the fundamental period of the signal can also be used as the phase of the signal. The fundamental period of the signal is the reciprocal of the fundamental frequency f0. For example, in the case of using a burst wave with a fundamental frequency f0 = 800 kHz, the fundamental period is 1.25 μs. The phase extraction unit 231 calculates the specific location of the received signal, for example, where the zero-crossing point is located within the fundamental period. In this embodiment, the phase extraction unit 231 calculates the remainder obtained by dividing the delay time by the fundamental period T0 of the signal, thereby calculating the phase within the fundamental period.

[0119] The data processing unit 201 includes a phase change calculation unit 232. The phase change calculation unit 232 receives phase information as an input signal and also receives scan position information from the scan controller 204. Using this two pieces of information, the phase change calculation unit 232 calculates the phase change of the phase information extracted by the phase extraction unit 231 in relation to the scan position (the phase change at each scan position). This change corresponds to the spatial differential component of the signal's phase information related to the scan position.

[0120] In the "phase change related to the scanning position", in addition to the change (spatial infinitesimal component), it also includes signal quantities (change quantities) that represent the magnitude change of the change (spatial infinitesimal component), such as its square value and absolute value. If a scan is performed in the xy two-dimensional plane and the change quantity is calculated for the two-dimensional scan position (x, y), an image of the contour of the defect D can be obtained that is easy to grasp.

[0121] The calculation method for the phase change of the phase information of the phase change calculation unit 232 includes, for example, arithmetic processing using a CPU (Central Processing Unit) or a microcomputer (microcontroller), digital signal processing using an FPGA (Field-Programmable Gate Array), and signal processing using analog circuits.

[0122] Thus, through the phase extraction unit 231 and the phase change calculation unit 232, the phase change of the signal is extracted at each scanning position in the x-axis and y-axis directions, and the phase change related to that scanning position is calculated. The signal changes caused by different scanning positions are explained below.

[0123] Figure 11 This diagram schematically illustrates the changes in the received signal of the eccentrically positioned receiving probe 120 at various scanning positions along the x-axis. The vertical dashed line represents the location of the defect D, and the width of the defect D is WD. For reference, graph G1 shows the signal amplitude when the coaxially positioned receiving probe 140 based on the transmission method is set. Graph G2 shows the signal amplitude of the signal received by the eccentrically positioned receiving probe 120, and is the output signal of the waveform analysis unit 221. It can be seen that in either graph G1 or G2, the signal amplitude increases near the defect D, and the defect D can be detected.

[0124] However, in either graphic G1 or G2, the signal width is wider than the size (width) of the defect D, i.e., WD. This is because the beam size of the ultrasonic beam U is relatively large. That is, when a portion of the ultrasonic beam U irradiates the defect D, a scattered wave U1 is also generated, and therefore, the signal amplitude of the scattered wave U1 gradually increases near the defect D. Consequently, the signal amplitude is wider than the actual size of the defect D. When this is represented on the display device 3, the size of the defect D appears larger than it actually is, corresponding to a reduced resolution. Therefore, if only graphics G1 and G2 are used, the resolution of the image displaying the outline of the defect D on the display device 3 may be reduced.

[0125] Graph G3 is a graph depicting the phase of the scattered wave U1 signal, and is the phase extraction unit 231 ( Figure 10 The output signal of ). It can be known that the scattered wave U1 ( Figure 6B The phase signal of ) in defect D ( Figure 6B The position of ) changes drastically. The reason for this is explained in [reference needed]. Figures 12A-12C As described below. Graph G4 is a graph plotting the phase change of the phase signal of the scattered wave U1 relative to the scanning position in the x-axis direction, and is the phase change calculation unit 232 ( Figure 10The output signal of the scattered wave U1 is shown in Figure G4. Figure G4 corresponds to the signal obtained by spatially differentiating the phase signal of the scattered wave U1 with respect to the scanning position along the x-axis. Furthermore, Figure G5 is a graph obtained by squaring the value of Figure G4. Based on Figures G4 and G5, it can be seen that a signal corresponding to the contour of the defect D, i.e., a high-resolution image representing the contour of the defect D, can be obtained. Therefore, by comparing Figure G2 with Figures G3 to G5, it can be seen that by calculating the phase change of the phase of the scattered wave U1 signal related to the scanning position, the defect D can be detected with good resolution.

[0126] Figure 12A This is a diagram showing the scanning position where the ultrasonic beam U did not strike the defect D. Figure 12B This diagram shows the scanning position where the ultrasonic beam U is incident on the defect D, but the transmitting shaft AX1 does not enter the defect D. Figure 12C This diagram shows the scanning position of the ultrasonic beam U incident on the defect D and the transmitting tone axis AX1 entering the defect D. According to the inventors' research, the reason for the abrupt change in the phase of the scattered wave U1 at the position of the defect D is speculated to be as follows.

[0127] When scanning at the position (x1) where the ultrasonic beam U has not yet struck the defect D ( Figure 12A Since no scattered wave U1 was generated, the above... Figure 11 The signal amplitudes shown in graphs G1 and G2 do not change. However, when the ultrasonic beam U is incident on the defect D, but the transmitting tone axis AX1 does not enter the scanning position (x2) of the defect D, the signal amplitude remains unchanged. Figure 12B Even if only a portion of the ultrasonic beam U is incident on the defect D, a scattered wave U1 is generated. Therefore, as described above... Figure 11 As shown in graphs G1 and G2, changes can be observed in the signal amplitude. However, as mentioned above... Figure 11 As shown in graphs G3 to G5, the phase remains unchanged. This is believed to be because the eccentrically configured receiving probe 120 receives components containing scattered wave U1 and ultrasonic beams U from various directions, which are mixed, making it difficult to confirm the phase change as the cause.

[0128] like Figure 12C As shown, when the ultrasonic beam U is incident on the defect D, and the transmitting tone axis AX1 enters the scanning position (x3) of the defect D, as described above... Figure 11 As shown in graphs G3 to G5, a significant phase change is observed. This is believed to be due to the ultrasonic beam U being incident on the defect D via its transmitting tone axis AX1, and the ultrasonic beam U being incident on the defect D in a manner suitable for scattering at the defect D. Therefore, it is believed that this is caused by the eccentrically positioned receiving probe 120 receiving most of the received component containing the scattered wave U1, resulting in a significant phase change.

[0129] Thus, when the transmitting axis AX1 of the ultrasonic beam U irradiates the defect D, that is, when the majority of the receiving component of the eccentrically positioned receiving probe 120 is the scattered wave U1, the phase change of the scattered wave U1 can be clearly captured. Therefore, the position of the defect D can be determined based on the phase change of the scattered wave U1.

[0130] Return to Figure 10 The data processing unit 201 processes the information related to the defect D of the inspected object E into an image or detects whether the defect D exists, thus processing the acquired information into a desired form. Furthermore, the images and information generated by the data processing unit 201 are displayed on the display unit 3.

[0131] Scan controller 204 drive control Figure 1 The transmitting probe scanning unit 103 and the receiving probe 104 are shown. The drive control of the transmitting probe scanning unit 103 and the receiving probe 104 is performed by the drive unit 202. In addition, the scanning controller 204 measures the position information (scanning positions in the x-axis direction and y-axis direction, xy coordinates) of the transmitting probe 110 and the eccentrically configured receiving probe 120 via the position measurement unit 203.

[0132] The data processing unit 201, based on the position information of the transmitting probe 110 and the eccentrically configured receiving probe 120 received from the scanning controller 204, plots signal strength data at each position, visualizes it, and displays it on the display device 3. As described above, the signal strength data obtained at the defective part D is greater than the signal strength data at the intact part N. Therefore, if signal strength data is plotted at the scanning position of the transmitting probe 110, an image indicating where the defective part D exists can be obtained. The display device 3 displays this image.

[0133] The data processing unit 201 generates an image by plotting the output signal from the phase change calculation unit 232 at the scanning position of the transmitting probe 110, and displays the image on the display device 3. As will be described later, the output signal from the phase change calculation unit 232 provides an image corresponding to the contour image of the defect unit D.

[0134] The image generated from the signal strength data and the image output by the phase change calculation unit 232 can also be displayed as a single image, superimposed on each other. The superimposed image is an image where the second image is displayed on top of the first image. In this case, the first and second images are superimposed in a manner that aligns the scan positions of the two images. For example, the signal strength data image can be represented by a grayscale black and white image, while the image output by the phase change calculation unit 232 can be superimposed using other colors such as yellow.

[0135] Figure 13This is a diagram showing the hardware structure of the control device 2. The control device 2 is configured to include memory such as RAM (Random Access Memory) 251, CPU (Central Processing Unit) 252, storage devices such as ROM (Read Only Memory) and HDD (Hard Disk Drive) 253, communication devices such as NIC (Network Interface Card) 254, and I / F (Interface) 255.

[0136] Control device 2 loads a specific control program stored in storage device 253 into memory 251, and executes it via CPU 252. Thus, Figure 3 The data processing unit 201, the position measurement unit 203, the scanning controller 204, the phase extraction unit 231, the phase change calculation unit 232, etc. are specified.

[0137] Figure 14 This is a flowchart illustrating the ultrasonic inspection method of the first embodiment. The ultrasonic inspection method of the first embodiment can be performed by the ultrasonic inspection apparatus Z described above, with appropriate reference. Figure 1 and Figure 10 The method described in the first embodiment involves ultrasound examination via gas G ( Figure 1 ) for the examined body E ( Figure 1 An ultrasonic beam U is incident on the object being inspected, thereby inspecting the object E. Furthermore, this ultrasonic inspection method is described with respect to an embodiment using gas G as the fluid F, but of course, this ultrasonic inspection method can also be applied to liquids W (…). Figure 17 This method is also effective as an implementation of fluid F.

[0138] First, according to control device 2 ( Figure 10 The instruction from probe 110 is used to send the signal. Figure 1 ) emits an ultrasonic beam U ( Figure 6B The transmission step S101 is performed. Next, the receiving probe 120 is configured in an eccentric position. Figure 1 The receiving step S102 is the receiving step of receiving the ultrasonic beam U (in this example, the scattered wave U1) in the ) .

[0139] Subsequently, based on the signal (e.g., waveform signal) of the ultrasonic beam U (scattered wave U1 in this example) received by the eccentrically configured receiving probe 120, a phase extraction step S103 is performed to extract the phase information of the signal. The phase extraction step S103 is performed by the phase extraction unit 231 ( Figure 10 The phase extraction unit 231, for example, extracts the phase from the aforementioned... Figure 4BThe received signal is used to extract (generate) the phase information of the signal.

[0140] The output signal of the phase extraction unit 231 is input to the phase change calculation unit 232. Figure 10 The phase change calculation step S104 calculates the phase change amount related to the scan position of the extracted phase information. In the phase change amount calculation step S104, the phase change amount is calculated with reference to the scan controller 204. Figure 10 The phase change is calculated per unit length change of the scan position based on the scan position information (coordinate position) sent. The phase change calculation step S104 is performed by the phase change calculation unit 232.

[0141] The scanning position information of the transmitting probe 110 and the eccentrically configured receiving probe 120 is transmitted from the position measurement unit 203. Figure 10 Send to scan controller 204 ( Figure 10 Data Processing Department 201 Figure 10 The phase change at each scanning position is plotted based on the scanning position information of the transmitting probe 110 obtained from the scanning controller 204. In this way, the phase change can be obtained as described above. Figure 11 The graphs G3 to G5 shown visualize the phase change.

[0142] In addition, the above Figure 11 In the case where the scanning position information is one-dimensional (one direction), in the case where the scanning position information is two-dimensional (x, y), the contour information of the defect D is represented by a two-dimensional image by plotting the phase change amount, and then displayed on the display device 3.

[0143] After the phase change amount calculation step S104, the shape display step S105 is performed. The shape display step S105 determines whether the phase change amount of the phase information generated in the phase change amount calculation step S104, related to the scan position, is above a preset threshold, and then displays the shape of the defect portion D of the inspected object E on, for example, the display device 3. The display device 3 displays, for example, an image depicting the scan position exceeding the threshold. This achieves the effect of clearly representing the outline of the defect portion D, which is therefore more preferable. The shape display step S105 is performed by the data processing unit 201.

[0144] The data processing unit 201 determines whether the scan is complete (step S111). If the scan is complete (Yes), the control device 2 ends the process. If the scan is incomplete (No), the data processing unit 201 controls the drive unit 202 ( Figure 10 The output command causes the transmitting probe 110 and the eccentrically configured receiving probe 120 to move to the next scanning position (step S112), and the processing is returned to the transmitting step S101.

[0145] Based on the ultrasonic inspection device Z and ultrasonic inspection method described above, the detection performance of defects can be improved, such as the resolution of the displayed image, and the location of the defect D can be easily determined.

[0146] In addition, fluid F can be gas G as described above ( Figure 1 ), or as described below, liquid W ( Figure 17 However, when using a gas such as air (G) as the fluid (F), it provides better performance for the following reasons.

[0147] Compared to liquid W, ultrasonic waves attenuate more significantly in gas G. It is known that the attenuation of ultrasonic waves in gas G is proportional to the square of the frequency. Therefore, the upper limit for ultrasonic wave propagation in gas G is approximately 1 MHz. In the case of liquid W, ultrasonic waves can propagate at frequencies from 5 MHz to tens of MHz; therefore, the usable frequencies in gas G are lower than those in liquid W.

[0148] Generally, as the frequency of ultrasound decreases, it becomes more difficult to converge the ultrasound beam U. Therefore, a 1 MHz ultrasound beam propagating in gas G has a larger convergent beam diameter compared to an ultrasound beam U in liquid W. Therefore, when using gas G as fluid F, a coaxial wiring receiving probe 140 ( Figure 2A The resolution of the detected amplitude image is reduced.

[0149] However, according to this disclosure, when using gas G as fluid F, an image can also be obtained in which the phase change (spatial micro-component) of the scattered wave U1 detected by the eccentrically configured receiving probe 120, related to the scanning position, is close to the contour image of the defect D. Therefore, high resolution is obtained not only when using liquid W as fluid F, but also when using gas G. Thus, the effect of this disclosure is even greater when using gas G as fluid F.

[0150] (Second Implementation)

[0151] Figure 15 This diagram schematically illustrates the structure of the ultrasonic testing apparatus Z according to the second embodiment. In this second embodiment, the scanning measurement apparatus 1 includes both an eccentrically positioned receiving probe 120 and a coaxially positioned receiving probe 140. Here, the coaxially positioned receiving probe 140 is the receiving probe 121 positioned at a point where the eccentricity distance L is zero. That is, the receiving tone axis AX2 of the coaxially positioned receiving probe 140 is the same as the transmitting tone axis AX1 of the transmitting probe 110.

[0152] Figure 16This diagram illustrates the structure of the control device 2 according to the second embodiment. The output signal of the eccentrically positioned receiving probe 120 is input to the receiving system 220a, where phase information is extracted by the phase extraction unit 231. The phase information is input to the data processing unit 201, where the phase change calculation unit 232 calculates the phase change of the signal related to the scanning position. This phase change, as described above, corresponds to the contour of the defect portion D. Contour image data is generated in the phase change calculation unit 232.

[0153] The output signal of the coaxial receiving probe 140 is input to the receiving system 220b, amplified by the signal amplifier 223, and the amplitude information of the signal is extracted by the waveform analysis unit 221. Since the receiving tone axis AX2 of the coaxial receiving probe 140 is set in the same manner as the transmitting tone axis AX1 of the transmitting probe 110, the transmission amount of the ultrasonic beam U in the defect section D is blocked, and thus the amplitude of the received signal of the coaxial receiving probe 140 is reduced in the defect section D. This is the prior art defect detection method under the "blocking mode". The output signal of the waveform analysis unit 221 of the receiving system 220b connected to the coaxial receiving probe 140 is input to the data processing unit 201, and the amplitude image generation unit 224 therein generates amplitude image data.

[0154] Following the above sequence, contour image data is generated from the signal received by the eccentrically configured receiving probe 120, and amplitude image data is generated from the signal received by the coaxially configured receiving probe 140. These two image data are input to the image synthesis unit 225 of the data processing unit 201. The image synthesis unit 225 synthesizes (overlays) the amplitude image data (first image) and the contour image data (second image). The amplitude image data, as described above, is based on the direct wave U3 received by the coaxially configured receiving probe 140. Figure 9A The amplitude of the wave is generated by the amplitude image generation unit 224, representing the position of the defect D inside the inspected object E. The contour image data is generated by the phase change calculation unit 232, based on the phase change amount related to the scanning position, representing the contour of the defect D inside the inspected object E. The synthesized image is input to the display device 3 and displayed.

[0155] When observing a defect D with a convergence size smaller than the ultrasonic beam U, the amplitude image data becomes an image with blurred outlines, but the outline image data provides a clear shape that is closer to the actual size of the defect D. Therefore, according to the second embodiment, it is possible to image the defect D at a higher resolution.

[0156] Furthermore, in the second embodiment, information (contour image data) obtained from the phase change calculation unit 232 based on the signal received by the eccentrically configured receiving probe 120, and information (amplitude image data) obtained from the amplitude image generation unit 224 based on the signal received by the coaxially configured receiving probe 140 are synthesized and displayed overlaid on the display device 3. However, in this disclosure, the effective utilization method of these two pieces of information, namely the phase change amount and amplitude information, is not limited to synthesizing two images.

[0157] The following describes other embodiments of the method for effectively utilizing these two pieces of information. In the following embodiments, by appropriately combining the phase change obtained from the signal received by the eccentrically configured receiving probe 120 and the amplitude obtained from the signal received by the coaxially configured receiving probe 140, a high-resolution image of the defect D can be generated and displayed.

[0158] As a first example of the method for combining these two signals, when the output signal of the phase change calculation unit 232 exceeds a predetermined threshold at a scanning position, and the change in the amplitude signal of the output signal from the waveform analysis unit 221 of the coaxially configured receiving probe 140 exceeds a predetermined threshold, it can be determined that a defect D exists at that scanning position. The information of the defect D thus determined, together with the scanning position information, is displayed as an image of the defect D on the display device 3. Therefore, when calculating the spatial change in phase change, i.e., the phase change amount, even if the signal changes due to unintentional noise interference, the false detection of the defect D can be suppressed.

[0159] In the second example, the output signal of the phase change calculation unit 232 can be used as the contour information of the defect D. Using the amplitude value of the received signal from the coaxially configured receiving probe 140, it is determined which region in the image divided by the contour line corresponds to the position of the defect D. Based on this determination, the defect image is displayed on the display device 3. Thus, the defect D can be displayed with good resolution.

[0160] (Third implementation)

[0161] Figure 17 This diagram illustrates the structure of the ultrasonic inspection apparatus Z according to the third embodiment. In the third embodiment, the fluid F is liquid W, and in the illustrated example, it is water. The ultrasonic inspection apparatus Z inspects the object E by incidenting an ultrasonic beam U onto the object E via the fluid F, i.e., liquid W. The object E is placed below the liquid surface L0 of the liquid W and is immersed in the liquid W. The ultrasonic inspection apparatus Z includes a scanning and measuring device 1, a control device 2, and a display device 3. The display device 3 is connected to the control device 2.

[0162] The scanning measurement device 1 is an apparatus for scanning and measuring an object E with an ultrasonic beam U. It includes a sample stage 102 fixed to a housing 101, on which the object E is placed. The object E is made of any material. For example, it may be a solid material, or more specifically, a metal, glass, or resin. Furthermore, the object E has a defect D inside. The defect D may be a cavity, etc. Examples of the defect D include cavities or foreign materials different from the intended material. The portion of the object E other than the defect D is called the intact portion N.

[0163] Because the defective part D and the intact part N are made of different materials, their acoustic impedances differ, causing a change in the propagation characteristics of the ultrasonic beam. This change is observed in the ultrasonic inspection device Z to detect the defective part D.

[0164] The scanning measurement device 1 includes a transmitting probe 110 that emits an ultrasonic beam U and an eccentrically positioned receiving probe 120. The transmitting probe 110 is mounted on the housing 101 via a transmitting probe scanning unit 103 and emits the ultrasonic beam U. The eccentrically positioned receiving probe 120 is positioned opposite the transmitting probe 110 to the object being inspected, E, and receives the ultrasonic beam U. The eccentrically positioned receiving probe 120 has a receiving axis AX2 at a position different from the transmitting axis AX1 of the transmitting probe 110. The distance between the transmitting axis AX1 and the receiving axis AX2 is the eccentric distance L. The eccentrically positioned receiving probe 120 is mounted on the housing 101 via a receiving probe scanning unit 104.

[0165] In addition, when using a liquid such as water W as the fluid F, the receiving probe 121 that receives ultrasonic waves will also be used. Figure 18 The probe positioned at an eccentricity distance L greater than or equal to zero is defined as an eccentrically positioned receiving probe 120, and the probe positioned at an eccentricity distance L of zero is defined as a coaxially positioned receiving probe 140. Figure 18 In other words, the term "receiver probe 121" is used to include both the eccentrically configured receive probe 120 and the coaxially configured receive probe 140.

[0166] In the third embodiment, for the transmitting probe 110, in Figure 17 The x-axis offset distance L is used to configure the eccentrically configured receiving probe 120, but it can also be configured in a different way. Figure 17 The receiving probe 120 is configured with an offset in the y-axis direction. Alternatively, the receiving probe 120 can be configured with an offset of L1 in the x-axis direction and an offset of L2 in the y-axis direction (i.e., the position of (L1, L2) if the position of the transmitting probe 110 in the xy plane is taken as the origin).

[0167] In the third embodiment, as a preferred example, the eccentrically configured receiving probe 120 receives the scattered wave U1 generated by the scattering of the ultrasonic beam U at the defect D. Figure 6B Because a scattered wave U1 is generated due to the presence of a defect D, the detection accuracy of the defect D can be further improved by detecting the scattered wave U1. In the following example, for the sake of simplicity, an eccentrically positioned receiving probe 120 located at a position that can receive the scattered wave U1 will be used as an example to illustrate this embodiment.

[0168] The eccentricity distance L is set such that the signal strength at the defective part D is greater than the received signal at the healthy part N of the inspected object E. This point is the same as in the first embodiment.

[0169] Regarding the control device 2 of the ultrasonic inspection apparatus Z in the third embodiment, further reference will be made to the above-described control device 2. Figure 10 The following will be explained. In the third embodiment, the control device 2 also includes a transmitting system 210, a receiving system 220, a data processing unit 201, a scanning controller 204, a drive unit 202, and a position measuring unit 203. The structure and operation of the control device 2 are the same as in the first embodiment.

[0170] The receiving system 220 includes a phase extraction unit 231. The output signal of the input signal amplifier 222 is received by the phase extraction unit 231. The phase information described above is generated from the received signal in the phase extraction unit 231. The generated phase information is then transmitted to the data processing unit 201.

[0171] The data processing unit 201 includes a phase change calculation unit 232. The phase change calculation unit 232 receives phase information as an input signal and also receives scan position information from the scan controller 204. Using these two pieces of information, the phase change calculation unit 232 calculates the phase change caused by the change in scan position.

[0172] Similar to the first embodiment, the amount of phase change caused by the change in scanning position corresponds to the contour information of the defect portion D. Therefore, by imagering the amount of phase change in relation to the scanning position, a high-resolution image of the defect portion can be obtained.

[0173] (Fourth implementation)

[0174] Figure 18 This diagram illustrates the structure of the ultrasonic testing apparatus Z according to the fourth embodiment. In this fourth embodiment, the scanning measurement apparatus 1 includes both an eccentrically positioned receiving probe 120 and a coaxially positioned receiving probe 140. Here, the coaxially positioned receiving probe 140 is the receiving probe 121 positioned at a point where the eccentricity distance L is zero. That is, the receiving tone axis AX2 of the coaxially positioned receiving probe 140 is the same as the transmitting tone axis AX1 of the transmitting probe 110.

[0175] Furthermore, in the fourth embodiment, the fluid F is liquid W, such as water. The ultrasonic inspection device Z of the fourth embodiment is, for example, composed of… Figure 16 Controlled by the control device 2 shown.

[0176] The fourth embodiment is similar to the second embodiment described above, synthesizing contour image data (second image) from amplitude image data (first image). The amplitude image data (first image) is based on data from a signal received by the coaxially configured receiving probe 140, and the synthesized contour image data (second image) is based on data from a signal received by the eccentrically configured receiving probe 120, and on data related to the amount of phase change associated with the change in scanning position. The image synthesis unit 225 ( Figure 16 This process is performed. Therefore, defects in part D can be detected at high resolution.

[0177] (Fifth implementation)

[0178] Figure 19 This diagram illustrates the structure of the ultrasonic inspection apparatus Z in the fifth embodiment. In the fifth embodiment, a transceiver probe 119 is included, replacing the ultrasonic inspection apparatus Z of the third embodiment. Figure 17 The transmitting probe 110 is responsible for transmitting the signal. The receiving probe 119 is responsible for receiving the signal in the coaxial configuration of the fourth embodiment. Figure 18 The function of the transmitting probe 110 in the third embodiment, and the function of the transmitting probe 110 in the third embodiment. Figure 17 Therefore, the transceiver probe 119 emits an ultrasonic beam U and receives reflected waves from the inspected object E (containing the defective part D).

[0179] Figure 20 This is a functional block diagram of the ultrasonic inspection device Z in the fifth embodiment. The transceiver probe 119 emits an ultrasonic beam U by being subjected to an excitation pulse output from the transmitting system 210 of the control device 2. Subsequently, the connection target of the transceiver probe 119 is immediately switched to the receiving system 220b of the control device 2. Typically, this switching is performed using a switch 235 within the control device 2. In the fifth embodiment, the switch 235 is, for example, a relay element or a semiconductor analog switch.

[0180] The transceiver probe 119 detects the ultrasonic beam U (reflected wave) reflected in the defect section D. The transceiver probe 119 converts the sound wave of the reflected wave into an electrical signal, which is then input to the receiving system 220b via switch 235. In the waveform analysis unit 221 within the receiving system 220b, the amplitude information of the reflected wave signal is extracted, and the amplitude image generation unit 224 generates amplitude image data (first image) based on the amplitude of the direct wave received by the transceiver probe 119.

[0181] On the other hand, the signal detected by the eccentrically configured receiving probe 120 is input to the receiving system 220a, and the phase information of the signal is extracted in the phase extraction unit 231. The phase change calculation unit 232 calculates the phase change of this phase information related to the scanning position, and generates contour image data (second image). The image synthesis unit 225 synthesizes and overlaps the amplitude image data and the contour image data, and outputs them to the display device 3. Thus, the two synthesized images are overlaid and displayed on the display device 3.

[0182] As described above, the shape of the defect D can be detected with better resolution by measuring the phase change of the scattered wave signal in relation to the scanning position. Therefore, the defect D can be imaged at a higher resolution. Furthermore, since the transceiver probe 119 also functions as the transmitting probe 110 ( Figure 17 ) and coaxial configuration receiving probe 140 ( Figure 18 The function of scanning measurement device 1 can be simplified by using the scanning measurement device 1.

[0183] Furthermore, the ultrasonic inspection device Z according to the fifth embodiment can be realized simply by offsetting the position of the coaxially configured receiving probe 140 of the existing blocking ultrasonic inspection device by an eccentric distance L. That is, the ultrasonic inspection device currently in use can be utilized, thereby reducing installation costs.

[0184] (Sixth implementation)

[0185] Figure 21 This diagram illustrates the relationship between the transmitting probe 110 and the eccentrically positioned receiving probe 120 of the ultrasonic testing apparatus Z according to the sixth embodiment. In the sixth embodiment, the convergence relationship between the transmitting probe 110 and the eccentrically positioned receiving probe 120 will be explained.

[0186] In the sixth embodiment, the convergence of the eccentrically configured receiving probe 120 is less pronounced than that of the transmitting probe 110. The propagation path of the scattered wave U1 varies slightly depending on the depth, shape, and tilt of the defect D within the inspected object E. Therefore, in the second embodiment, the convergence of the eccentrically configured receiving probe 120 is less pronounced so that the scattered wave U1 can be detected even if its path changes.

[0187] The magnitude of convergence is defined by the relationship between the incident beam areas T1 and T2 on the surface of the object being inspected, E. The incident beam areas T1 and T2 will be explained below.

[0188] Figure 22This diagram illustrates the relationship between the beam incident area T1 of the transmitting probe 110 and the beam incident area T2 of the eccentrically configured receiving probe 120. The beam incident area T1 of the transmitting probe 110 is the intersection area of ​​the ultrasonic beam U emitted from the transmitting probe 110 with the surface of the object being inspected, E. Furthermore, the beam incident area T2 of the eccentrically configured receiving probe 120 is the intersection area of ​​a virtual ultrasonic beam U2 assuming the ultrasonic beam U is emitted from the eccentrically configured receiving probe 120 with the surface of the object being inspected, E.

[0189] In addition, Figure 22 In the diagram, the path of the ultrasonic beam U represents the path when the object E is not present. When the object E is present, the ultrasonic beam U propagates along a different path than the one shown by the dashed line because of refraction on the surface of object E. Here, as... Figure 22 As shown, the beam incident area T2 of the eccentrically configured receiving probe 120 on the inspected object E is greater than the beam incident area T1 of the transmitting probe 110 on the inspected object E. This allows the convergence of the eccentrically configured receiving probe 120 to be less pronounced than that of the transmitting probe 110.

[0190] Furthermore, the focal length R2 of the eccentrically configured receiving probe 120 is longer than the focal length R1 of the transmitting probe 110. This also allows the convergence of the eccentrically configured receiving probe 120 to be less pronounced than that of the transmitting probe 110. In this case, the distances from the object under inspection E to both the transmitting probe 110 and the eccentrically configured receiving probe 120 may be the same, but they may also be different.

[0191] Thus, in the sixth embodiment, the focusing property of the eccentrically configured receiving probe 120 is less concentrated than that of the transmitting probe 110. That is, the focal length R2 of the eccentrically configured receiving probe 120 is set to be longer than the focal length R1 of the transmitting probe 110. As a result, since the beam incident area T2 of the eccentrically configured receiving probe 120 is wider, a wider range of scattered waves U1 can be detected. Therefore, even if the propagation path of the scattered wave U1 changes slightly, the scattered wave U1 can still be detected by the eccentrically configured receiving probe 120. Consequently, a wider range of defects D can be detected.

[0192] Furthermore, the focal point of the eccentrically configured receiving probe 120 is located on the side closer to the transmitting probe 110 than the focal point of the transmitting probe 110 (upper in the example). By shifting the focal point, the scattered wave U1 can be easily received by the eccentrically configured receiving probe 120, and the scattered wave U1 can be easily detected.

[0193] Alternatively, the non-converging probe used in the first embodiment can be used as the off-center receiving probe 120. Since the focal length R2 of the non-converging probe is infinitely large, it is longer than the focal length R1 of the transmitting probe 110. That is, even if it is a non-converging off-center receiving probe 120, the convergence of the off-center receiving probe 120 is less than that of the transmitting probe 110.

[0194] (Seventh implementation)

[0195] Figure 23 This is a diagram illustrating an example of the eccentrically configured receiving probe 120 in the seventh embodiment. It is a top view of the transmitting probe 110 and the eccentrically configured receiving probe 120 of the ultrasonic testing apparatus Z, viewed from the negative side of the z-axis. That is, Figure 23 This is a view taken from the side of the eccentrically configured receiving probe 120. In the third embodiment, the oscillator 111 of the eccentrically configured receiving probe 120 ( Figure 3 The length b of the receiving tone shaft AX2 relative to the transmitting tone shaft AX1 in the eccentric direction is longer than the length a in the direction along the surface of the object being inspected E and orthogonal to the eccentric direction. Lengths a and b are characteristic lengths, which for a rectangular oscillator refer to the length of the rectangular side, and for an elliptical oscillator refer to the major or minor axis of the ellipse.

[0196] If the aspect ratio of the eccentrically configured receiving probe 120 is set in this way, the eccentrically configured receiving probe 120 can detect the eccentrically configured receiving probe 120 even if the depth of the defect D changes or the arrival position of the scattered wave U1 changes.

[0197] The scattered wave U1 is scattered in the radial direction with the transmitting tone axis AX1 as the center. Therefore, in Figure 23 When the receiving probe 120 is positioned off-center, the scattered wave U1 is scattered along the long side of the off-center receiving probe 120 (the direction of extension of "length b"). In other words, the direction of extension of "length b" is the direction in which the scattered wave U1 is emitted. Therefore, by increasing the value of "length b", the scattered wave U1 scattered by the defect portion D at various depths can be detected. 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 still be detected by the off-center receiving probe 120.

[0198] The lengths a and b are not limited, as long as the length b is longer than the length a, i.e., 1 < b / a. The upper limit of b / a (the value of length b divided by length a) is, for example, less than 100, preferably less than 50.

[0199] In addition, Figure 23 The figure shows an eccentrically configured receiving probe 120 in a cuboid (rectangular shape). As an eccentrically configured receiving probe 120, but set to an elliptical shape, the same effect can be obtained by setting the major axis ratio and minor axis ratio.

[0200] (Eighth embodiment)

[0201] Figure 24 This diagram illustrates the structure of the scanning measurement device 1 of the ultrasonic inspection apparatus Z according to the eighth embodiment. In the eighth embodiment, the scanning measurement device 1 includes a setting angle adjustment unit 106 for adjusting the tilt of the eccentrically positioned receiving probe 120. This increases the strength of the received signal and improves the signal-to-noise ratio (SN ratio). The setting angle adjustment unit 106, for example (not shown), is composed of an actuator, motor, or the like.

[0202] Here, the angle θ between the transmitting tone axis AX1 and the receiving tone axis AX2 is defined as the receiving probe setting angle. Figure 24 In this case, since the transmitting probe 110 is positioned vertically, the transmitting tone axis AX1 is also vertical. Therefore, the angle θ of the receiving probe is the angle between the transmitting tone axis AX1 (i.e., the vertical direction) and the normal to the probe surface of the eccentrically positioned receiving probe 120. Furthermore, by providing the angle adjustment unit 106, the angle θ is tilted to the side towards the transmitting tone axis AX1, and the angle θ is set to a value greater than zero. That is, the eccentrically positioned receiving probe 120 is tilted. Specifically, the eccentrically positioned receiving probe 120 is tilted in such a way that 0° < θ < 90°, and the angle θ is, for example, 10°, but is not limited to this.

[0203] Furthermore, the eccentricity distance L when the eccentrically configured receiving probe 120 is tilted is defined as follows: The intersection point C2 of the receiving tone shaft AX2 and the probe surface of the eccentrically configured receiving probe 120 is defined. The intersection point C1 of the transmitting tone shaft AX1 and the probe surface of the transmitting probe 110 is defined. The distance between the coordinates (x4, y4) of the intersection point C1 projected onto the xy plane and the coordinates (x5, y5) of the intersection point C2 projected onto the xy plane is defined as the eccentricity distance L.

[0204] With the receiving probe 120 configured in such an eccentric and tilted manner, the signal strength of the received signal increases by three times compared to the case where θ=0 when the inventors actually perform the detection of the defect D.

[0205] Figure 25 This diagram illustrates the reason for the effect of the eighth embodiment. The scattered wave U1 propagates in a direction deviating from the transmitting tone axis AX1. Therefore, as... Figure 25As shown, when the scattered wave U1 reaches the outside of the object being inspected E, it is incident at the interface between the object being inspected E and the outside at an angle α2 that is non-zero with respect to the normal vector of the surface of the object being inspected E. Furthermore, the angle of the scattered wave U1 emitted from the surface of the object being inspected E has an exit angle β2 that is non-zero relative to the normal direction of the surface of the object being inspected E. When the normal vector of the probe surface of the eccentrically configured receiving probe 120 is aligned with the direction of travel of the scattered wave U1, the scattered wave U1 can be received with optimal efficiency. That is, by tilting the eccentrically configured receiving probe 120, the received signal strength can be increased.

[0206] Furthermore, the reception effect is highest when the angle β2 of the ultrasonic beam U emitted from the object being inspected E coincides with the angle θ formed by the transmitting sound axis AX1 and the receiving sound axis AX2. However, even when the angle β2 and angle θ are not perfectly aligned, an increased received signal can still be achieved. Figure 25 As shown, angle β2 and angle θ may not be completely identical.

[0207] In addition, in the scanning measurement device 1 ( Figure 24 The device includes an angle adjustment unit 106, through which an eccentrically configured receiving probe 120 is positioned. The angle adjustment unit 106 can adjust the receiving probe setting angle of the eccentrically configured receiving probe 120. Since the path of the scattered wave U1 varies slightly depending on the material and thickness of the object being inspected E, the optimal value of the setting angle of the eccentrically configured receiving probe 120 also varies. Therefore, by adjusting the receiving probe setting angle through the angle adjustment unit 106, the setting angle of the eccentrically configured receiving probe 120 can be appropriately adjusted according to the material and thickness of the object being inspected E.

[0208] Furthermore, in the eighth embodiment, the eccentrically configured receiving probe 120 is arranged in a state of inclination relative to the horizontal plane, but the transmitting probe 110 can also be arranged in an inclination state. Alternatively, the transmitting probe 110 can be arranged in a state of inclination relative to the horizontal plane, and the probe surface of the eccentrically configured receiving probe 120 can be arranged in a manner parallel to the horizontal plane (xy plane). In either case, the above description applies. Figure 2B As shown, the transmitting tone axis AX1 and the receiving tone axis AX2 are configured in an offset state.

[0209] Furthermore, in order to obtain the tilt configuration effect described in this embodiment, the angle θ (tilt angle) is set within the range of 0° < θ < 90°. On the other hand, in other embodiments of this disclosure, θ = 0° is of course also possible.

[0210] (9th implementation)

[0211] Figure 26This diagram illustrates the structure of the ultrasonic testing apparatus Z according to the ninth embodiment. In the ninth embodiment, the eccentrically configured 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 respectively disposed at positions with different eccentric distances L (distances from the transmitting tone axis AX1).

[0212] Depending on the depth, shape, and tilt of the defect D, the path of the scattered wave U1 varies slightly. For example, the scattering angle (the angle between the scattered wave U1 and the transmitting tone axis AX1) is usually the same. Therefore, the deeper the defect D, the closer the scattered wave U1 reaches the transmitting tone axis AX1; the shallower the defect D, the farther the scattered wave U1 reaches from the transmitting tone axis AX1. Therefore, by using multiple unit probes 120a and using information from which unit probe 120a received the data, information related to the defect D (such as the depth of the defect D) can be obtained.

[0213] As multiple unit probes 120a, multiple acoustic elements 122a can also be used. Figure 28 and Figure 29 ) An array of probes 122 housed in a housing Figure 28 and Figure 29 In this situation, Figure 26 Each unit probe 120a corresponds to a sound-sensing element, and they are housed in a housing. The sound-sensing element is a component that converts ultrasonic waves into electrical signals. In addition to piezoelectric elements, electrostatic capacitive sound-sensing elements (CMUT, Capacitive Micro-machined Ultrasonic Transducer) can also be used as sound-sensing elements.

[0214] Figure 27 This is a functional block diagram of the ultrasonic testing apparatus Z according to the ninth embodiment. Multiple unit probes 120a are connected to their respective receiving systems 220c, 220d, and 220e. The structures of each receiving system 220c, 220d, and 220e are similar to... Figure 10 The receiving systems 220 shown have the same structure. That is, receiving systems 220c, 220d, and 220e are... Figure 27 None of them are illustrated, but as Figure 10As shown, the system includes a signal amplifier 222, a waveform analysis unit 221, and a phase extraction unit 231. Signals from each unit probe 120a are amplified by the signal amplifier 222 and input to the waveform analysis unit 221 and the phase extraction unit 231. The waveform analysis unit 221 outputs the amplitude of the received signal (scattered wave U1), and the phase extraction unit 231 outputs the phase information of the received signal (scattered wave U1). These outputs from the receiving systems 220c, 220d, and 220e are then input to the defect information determination unit 205.

[0215] The defect information determination unit 205 is equipped in the control device 2. Based on the received signal of the unit probe 120a among the plurality of unit probes 120a that receives the scattered wave U1 generated by the scattering of the irradiated ultrasonic beam U by the defect D of the inspected object E, it determines information related to the defect D in the inspected object E (such as the depth of the defect D). Specifically, the defect information determination unit 205 determines the receiving system 220 most suitable for observing the scattered wave U1 based on the amplitude information from the waveform analysis units 221 of each of the receiving systems 220c, 220d, and 220e. In the ninth embodiment, the defect information determination unit 205 selects the receiving system 220 with the largest amplitude. Then, the phase information from the phase extraction unit 231 of the selected receiving system 220 is output to the data processing unit 201.

[0216] The defect information determination unit 205 determines information related to the defect D based on the waveform analysis results of the receiving systems 220c, 220d, and 220e. "Based on the received signal" refers to which unit probe 120a detected which level of received signal (scattered wave U1). This improves the accuracy of the location information of the defect D.

[0217] The output of the defect information determination unit 205 is input to the data processing unit 201. The data processing unit 201 includes a phase change calculation unit 232. The phase change calculation unit 232 matches the scan position information from the scan controller 204 of the scan probe to calculate the phase change of the received signal related to the scan position change. As described above, this phase change related to the scan position change provides an image corresponding to the contour information of the defect D. This information is visualized and displayed on the display device 3.

[0218] Alternatively, the defect information determination unit 205 can also be designed as part of the data processing unit 201.

[0219] (10th implementation)

[0220] Figure 28 This diagram illustrates the configuration of the eccentrically positioned receiving probe 120 according to the tenth embodiment. In this example, it is from... Figure 1The top view of the transmitting probe 110 and the eccentrically configured receiving probe 120 is taken from the negative side of the z-axis, i.e., the side of the eccentrically configured receiving probe 120. In the 10th embodiment, the eccentrically configured receiving probe 120 is configured two-dimensionally in the xy-plane direction. That is, the eccentrically configured receiving probe 120 includes a plurality of rectangular unit probes 120a in top view, and the plurality of unit probes 120a are arranged radially around the transmitting tone axis AX1. In the illustrated example, there are 8 unit probes 120a.

[0221] The direction of the scattered wave U1 varies slightly depending on the shape and tilt direction of the defect D. Therefore, as... Figure 28 The unit probe 120a is arranged radially to record the direction in which the scattered wave U1 is detected, thereby obtaining information such as the shape and tilt direction of the defect D with higher precision.

[0222] (11th implementation)

[0223] Figure 29 This diagram illustrates the configuration of the eccentrically arranged receiving probe 120 in the 11th embodiment, specifically the tilted arrangement of the unit probes 120a. Multiple unit probes 120a are symmetrically arranged relative to the transmitting tone axis AX1. Therefore, at least two unit probes 120a are arranged at positions with the same eccentricity distance L. In the illustrated example, when viewed from above including the transmitting tone axis AX1, three unit probes 120a are symmetrically arranged on each side of the transmitting tone axis AX1. Furthermore, two unit probes 120a are arranged at each of three different eccentricity distances L. Additionally, the unit probes 120a are similar to those in the 8th embodiment described above (…). Figure 25 Similarly, it is tilted.

[0224] Figure 30 This diagram illustrates the configuration of the eccentrically arranged receiving probes 120 in the 11th embodiment, showing the unit probes 120a arranged in the vertical direction. One set of unit probes 120a is symmetrically arranged with respect to the transmitting tone axis AX1. Therefore, at least two unit probes 120a are arranged at positions with the same eccentricity distance L.

[0225] By placing at least two unit probes 120a at positions with the same eccentricity L, scattered waves U1 scattered in multiple directions can be detected. Additionally, from a top-down view including the transmitting tone axis AX1 ( Figure 29 and Figure 30 When the transmission shaft AX1 is in operation, at least two unit probes 120a are arranged on both sides, thereby receiving a wide range of scattered waves U1. Furthermore, the control device 2 can determine that a defect D has been actually detected when scattered waves U1 are detected by each of the unit probes 120a on both sides, and determine that an error has occurred when scattered waves U1 are detected only by one side. This improves the detection accuracy of the defect D.

[0226] (12th implementation)

[0227] Figure 31 This diagram illustrates the structure of the ultrasonic testing apparatus Z according to the 12th embodiment. In the 12th embodiment, the focal length R3 of the coaxially configured receiving probe 140 is shorter than the focal length R2 of the eccentrically configured receiving probe 120. As a result, the convergence of the coaxially configured receiving probe 140 is improved compared to that of the eccentrically configured receiving probe 120.

[0228] By making the focal length R3 of the coaxial receiving probe 140 shorter than the focal length R2 of the eccentric receiving probe 120, the coaxial receiving probe 140 can efficiently receive the ultrasonic beam U on the receiving tone axis AX2 of the ultrasonic beam U emitted from the self-transmitting probe 110. On the other hand, since the scattered wave U1 has multiple propagation paths, the eccentric receiving probe 120, which receives it, can fully receive the scattered wave U1. Therefore, by using a receiving probe 121 with convergence that matches the characteristics of both the direct wave U3 and the scattered wave U1, defects can be detected more effectively.

[0229] (13th implementation)

[0230] Figure 32 This diagram illustrates the structure of the ultrasonic testing apparatus Z according to the 13th embodiment. In the 13th embodiment, an array-type probe 122 is used, which functions as both an eccentrically positioned receiving probe 120 and a coaxially positioned receiving probe 140. The array-type probe 122 consists of a plurality of acoustic elements 122a (also serving as unit probes 120a). Figure 26 (Function) One-dimensional ( Figure 32 ) or two-dimensional ( Figure 33 The receiving probe 121 is configured.

[0231] The array-type probe 122 is configured such that the receiving tone axis AX2 of a single acoustic element 122a is aligned with the transmitting tone axis AX1. The acoustic element 122a configured in this way functions as a coaxial receiving probe 140. The remaining acoustic elements 122a are similar to those described above. Figure 26 Similarly, the example shown is centered on the transmitting tone axis AX1. Figure 32 In this example, the sensors 122a are arranged continuously and symmetrically in the left-right direction on the paper, functioning as an off-center receiving probe 120. The sound-sensing element 122a is arranged one-dimensionally in this example.

[0232] By using an array-type probe 122 to unidimensionally arrange the acoustic elements 122a, the number of acoustic elements 122a required is reduced, thus lowering the setup cost of the array-type probe 122. Furthermore, multiple acoustic elements 122a can receive the scattered wave U1. Additionally, even when the defect D is small and completely blocks ultrasonic wave propagation, the acoustic elements 122a with a receiving acoustic axis AX2 aligned with the transmitting acoustic axis AX1 can detect a reduction in signal intensity. Therefore, efficient detection is possible for defects ranging from small to large.

[0233] (14th implementation)

[0234] Figure 33 This is a diagram showing the structure of the ultrasonic inspection device Z according to the 14th embodiment. Figure 33 From Figure 1 A top view of the transmitting probe 110 and the array probe 122 observed from the negative z-axis side, i.e., the side of the array probe 122. In the above... Figure 32 In this configuration, the acoustic elements 122a constituting the array-type probe 122 are arranged in only one dimension in one direction. However, in Figure 33 In the array-type probe 122 shown, the acoustic elements 122a are arranged two-dimensionally in the x and y directions. In the illustrated example, the same number (7 in each direction) of acoustic elements 122a are arranged in a square shape. However, the acoustic elements 122a are not limited to a square shape; they can also be arranged in various shapes such as rectangles, circles, and ellipses.

[0235] By using an array-type probe 122 and arranging the acoustic elements 122a in a two-dimensional configuration, more acoustic elements 122a can receive the scattered wave U1, thus suppressing the missed detection of the scattered wave U1. Furthermore, even when the defect D is large and completely blocks the propagation of ultrasound, the acoustic elements 122a with a receiving acoustic axis AX2 aligned with the transmitting acoustic axis AX1 can still detect the reduction in signal quantity. Therefore, defects ranging from small to large can be detected efficiently.

[0236] In the above embodiments, examples are described where the defect portion D is a cavity. However, the defect portion D can also be a foreign object mixed in with a material different from that of the inspected object E. In this case, since there is a difference in acoustic impedance (Gap) at the interface where different materials meet, a scattered wave U1 is generated, making the structures of the above embodiments more effective. The ultrasonic inspection device Z according to this embodiment is based on an ultrasonic defect imaging device, but it can also be applied to a non-contact series internal defect inspection device.

[0237] This disclosure is not limited to the above-described embodiments and includes various modifications. For example, the above embodiments have been described in detail for the purpose of illustrative purposes and are not necessarily limited to all structures described. Furthermore, a portion of the structure of one embodiment may be replaced with a structure of another embodiment, or a structure of another embodiment may be added to the structure of one embodiment. Additionally, for a portion of the structure of each embodiment, other structures may be added, deleted, or replaced.

[0238] Furthermore, the aforementioned structures, functions, and components of the block diagram can also be implemented in hardware, for example, by designing some or all of them using integrated circuits. Additionally, as... Figure 13 As shown, the aforementioned structures and functions can also be implemented in software by having a processor such as the CPU252 interpret and execute the programs that implement each function. In addition to being stored on an HDD, the information such as programs, tables, and files that implement each function can also be stored on memory, SSD (Solid State Drive) and other recording devices, or on recording media such as IC (Integrated Circuit) cards, SD (Secure Digital) cards, and DVD (Digital Versatile Disc).

[0239] Furthermore, in each embodiment, control lines and information lines are shown as those deemed necessary for the description; not all control lines and information lines may be shown on the manufactured product. It can be assumed that almost all structures are actually interconnected.

[0240] Symbol Explanation

[0241] 1: Scanning Measurement Device

[0242] 101: Shell

[0243] 102: Sample Stage

[0244] 103: Send probe scanning unit

[0245] 104: Receiving probe scanning unit

[0246] 105: Eccentricity Adjustment Section

[0247] 106: Set angle adjustment section

[0248] 110: Send probe

[0249] 111: Vibrator

[0250] 112: Backing

[0251] 113: Matching Layer

[0252] 114: Probe surface

[0253] 115: Send probe housing

[0254] 116: Connector

[0255] 117, 118: Lead wires

[0256] 119: Transceiver Probe

[0257] 120: Off-center configuration of the receiving probe

[0258] 120a: Unit probe

[0259] 121: Receiver probe

[0260] 122: Array-type probe

[0261] 122a: Sound sensor

[0262] 140: Coaxial configuration receiver probe

[0263] 2: Control device

[0264] 201: Data Processing Department

[0265] 202: Drive Unit

[0266] 203: Position Measurement Department

[0267] 204: Scan Controller

[0268] 205: Defect Information Judgment Department

[0269] 210: Sending System

[0270] 211: Waveform Generator

[0271] 212: Signal Amplifier

[0272] 220, 220a, 220b: Receiving system

[0273] 221: Waveform Analysis Section

[0274] 222, 223: Signal amplifiers

[0275] 224: Amplitude Image Generation Unit

[0276] 225: Image Composition Unit

[0277] 231: Phase Extraction Unit

[0278] 232: Phase Change Calculation Unit

[0279] 235: Switch

[0280] 251: Memory

[0281] 252: CPU

[0282] 253: Storage device

[0283] 254:Communication device

[0284] 255:I / F

[0285] 3: Display device

[0286] AX1: Send tone shaft

[0287] AX2: Receiver toneshaft

[0288] D: Defects Department

[0289] E: The body being inspected

[0290] F: Fluid

[0291] G: Gas

[0292] G1, G2, G3, G4, G5: Graphics

[0293] N: sound part

[0294] S101: Launch Procedure

[0295] S102: Receiving Steps

[0296] S103: Phase Extraction Steps

[0297] S104: Steps for calculating phase change

[0298] S105: Shape Display Steps

[0299] S111, S112: Steps

[0300] U: Ultrasonic beam

[0301] U1: Scattered wave

[0302] U2: Ultrasonic beam

[0303] U3: Direct Wave

[0304] Z: Ultrasonic inspection device

Claims

1. An ultrasonic inspection apparatus that performs inspection of an object under inspection by irradiating an ultrasonic beam to the object under inspection via a fluid, the ultrasonic inspection apparatus comprising: a scanning measurement apparatus that performs scanning and measurement of the ultrasonic beam to the object under inspection; and a control apparatus that controls driving of the scanning measurement apparatus; the scanning measurement apparatus comprising a transmitting probe that transmits the ultrasonic beam, and an eccentrically-arranged receiving probe that receives an ultrasonic beam, the scanning measurement apparatus being configured so that the eccentrically-arranged receiving probe is arranged at a distance from the transmitting axis of the transmitting probe that is greater than zero, the transmitting probe and the eccentrically-arranged receiving probe perform scanning in an x-axis direction or a y-axis direction, the transmitting probe is arranged so that the transmitting axis is perpendicular to an xy plane formed by the x-axis direction and the y-axis direction, the control apparatus comprises: a phase extraction section that extracts phase information of a signal of the ultrasonic beam received by the eccentrically-arranged receiving probe; and a phase change amount calculation section that calculates a phase change amount of the extracted phase information with respect to a scanning position.

2. 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 defect portion of the object under inspection can be received.

3. The ultrasonic inspection apparatus according to claim 1 or 2, wherein the eccentric distance is set so that a received signal intensity received by the eccentrically-arranged receiving probe when the ultrasonic beam is irradiated to a defect portion of the object under inspection is greater than the received signal intensity when the ultrasonic beam is irradiated to a healthy portion of the object under inspection.

4. The ultrasonic inspection apparatus according to claim 1 or 2, wherein the eccentric distance is set to a distance at which no received signal other than noise is detected when the ultrasonic beam is irradiated to a healthy portion of the object under inspection.

5. The ultrasonic testing apparatus according to claim 1 or 2, characterized by further comprising: an eccentric distance adjustment section that adjusts a position of at least one of the transmitting probe or the eccentrically-arranged receiving probe.

6. The ultrasonic inspection apparatus according to claim 1 or 2, wherein a focal length of the eccentrically-arranged receiving probe is longer than a focal length of the transmitting probe.

7. The ultrasonic inspection apparatus according to claim 1 or 2, wherein a focal point of the eccentrically-arranged receiving probe exists closer to the transmitting probe than a focal point of the transmitting probe.

8. The ultrasonic inspection apparatus according to claim 1 or 2, wherein a beam irradiation area of the eccentrically-arranged receiving probe on the object under inspection is larger than a beam irradiation area of the transmitting probe on the object under inspection.

9. The ultrasonic inspection apparatus according to claim 1 or 2, wherein the scanning measurement apparatus comprises a setting angle adjustment section that adjusts an inclination of the eccentrically-arranged receiving probe so that an angle θ formed by the transmitting axis and the receiving axis satisfies 0° < θ < 90°.

10. The ultrasonic inspection apparatus according to claim 1 or 2, wherein The eccentric configuration receiving probe comprises multiple unit probes.

11. The ultrasonic inspection device according to claim 10, characterized in that, The control device includes a defect information determination unit, which determines information related to the defect in the inspected object based on the received signal of one of the plurality of unit probes that receives the scattered wave generated by the irradiated ultrasonic beam due to the scattering of the defect in the inspected object.

12. The ultrasonic inspection device according to claim 1 or 2, characterized in that, The scanning measurement device includes a coaxially configured receiving probe, which is positioned at a point where the eccentricity is zero.

13. The ultrasonic inspection device according to claim 12, characterized in that, The control device includes an image compositing unit that combines the first image and the second image. The first image is an image representing the location of the internal defect of the inspected object, generated based on the amplitude of the direct wave received by the coaxially configured receiving probe. The second image is an image representing the outline of an internal defect of the inspected object, generated by the phase change calculation unit based on the phase change amount related to the scanning position.

14. The ultrasonic inspection device according to claim 1 or 2, characterized in that, The transmitting probe is a transceiver probe that emits the ultrasonic beam and receives reflected waves from the object being examined.

15. The ultrasonic inspection device according to claim 14, characterized in that, The control device includes an image compositing unit that combines the first image and the second image. The first image is an image representing the location of internal defects in the inspected object, generated based on the amplitude of the direct wave received by the transceiver probe. The second image is an image representing the outline of an internal defect of the inspected object, generated by the phase change calculation unit based on the phase change amount related to the scanning position.

16. The ultrasonic inspection device according to claim 1 or 2, characterized in that, The fluid is a gas.

17. An ultrasonic inspection method comprising inspecting the subject by incident an ultrasonic beam onto the subject via a fluid. The transmitting probe and the eccentrically configured receiving probe scan in either the x-axis or y-axis direction. The transmitting probe is configured such that its transmitting tone axis is perpendicular to the xy plane formed by the x-axis and the y-axis directions. The ultrasonic examination method has the following characteristics: The transmission step involves emitting an ultrasonic beam from the transmitting probe; The receiving step involves receiving the ultrasonic beam in an eccentrically configured receiving probe that has a receiving tone axis at a position different from the transmitting tone axis. The phase extraction step involves extracting the phase information of the ultrasonic beam signal received by the eccentrically configured receiving probe. as well as The phase change calculation step calculates the phase change of the extracted phase information in relation to the scanning position.

18. The ultrasonic inspection method of claim 17, wherein, It also has: In the shape display step, the shape of the defect portion of the inspected object is displayed by determining whether the phase change amount of the phase information generated in the phase change amount calculation step, which is related to the scanning position, is above a preset threshold.

19. The ultrasonic examination method according to claim 17 or 18, characterized in that, The fluid is a gas.

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