The present disclosure relates to an ultrasonic inspection device.
Conventionally, there is an ultrasonic inspection device that has a transmission unit that transmits ultrasonic waves to a subject and a reception unit that receives ultrasonic waves having transmitted through the subject, and that detects defects inside the subject by analyzing the reception state of the ultrasonic waves with respect to the reception unit. Japanese Unexamined Patent Application, First Publication No. JP 2020-176916 discloses an ultrasonic inspection device (ultrasonic flaw detector) which can detect defects inside an inspection target body highly precisely by making the reception surface of the reception unit smaller than the transmission surface of the transmission unit.
However, with conventional ultrasonic inspection devices, there is a problem in that it takes time to inspect defects in a subject highly precisely (high resolution) over a wide range.
The present disclosure has been made in view of the circumstances described above. An object of the present disclosure is to provide an ultrasonic inspection device capable of inspecting defects in a subject highly precisely and in a short time, even if the subject to be inspected has a large area.
According to a first aspect of the present disclosure, an ultrasonic inspection device includes a transmitter configured to transmit an ultrasonic beam to a subject. The ultrasonic inspection device further includes a plurality of receivers that each have a reception surface configured to receive the ultrasonic beam having transmitted through the subject. An area of the reception surface of each of the plurality of receivers is equal to or less than (10×λ)2, where λ is a wavelength of the ultrasonic beam.
Hereinafter, embodiments of the present disclosure are described with reference to
As shown in
In the drawing, the direction in which the container members 101 overlap at the joint portion 103 is indicated by the Z-axis direction. Also, the direction away from the non-joint portion 105 of the container member 101, that forms the accommodation space 102 and is not joined, is defined as the width direction of the joint portion 103 and is indicated by the Y-axis direction. Also, the longitudinal direction of the joint portion 103 orthogonal to the Z-axis direction and the Y-axis direction is indicated by the X-axis direction.
As shown in
The transmitter 10 has a transmission surface 10a that transmits an ultrasonic beam W toward the subject 100. In this embodiment, the transmitter 10 transmits the ultrasonic beam W toward the joint portion 103 of the packaging container, which is the subject 100. The ultrasonic beam W transmitted from the transmitter 10 passes through the joint portion 103 substantially in the direction in which the container members 101 overlap. The direction in which the ultrasonic beam W passes through the joint portion 103 is not strictly limited to the direction in which the container members 101 overlap (the Z-axis direction), but may be a direction that is inclined with respect to the direction in which the container members 101 overlap.
In this embodiment, the transmission surface 10a of the transmitter 10 is formed in an arcuate shape recessed to the Z-axis positive direction side when viewed from the Y-axis direction, as shown in
With the transmission surface 10a formed as described above, the ultrasonic beam W transmitted from the transmission surface 10a of the transmitter 10, converges (focuses) in the X-axis direction as it goes in the Z-axis negative direction as shown in
The reception unit 20 has a plurality of receivers 21. Each receiver 21 has a reception surface 21a that receives the ultrasonic beam W having transmitted through the subject 100. The area of the reception surface 21a is limited, and is expressed using the wavelength of the ultrasonic beam W. The area of the reception surface 21a is, for example, not more than (10×λ)2, where X is the wavelength of the ultrasonic beam W.
The reception surface 21a of the receiver 21 may be formed in a square shape, for example, as shown in
The reception surface 21a of the receiver 21 may be formed in a rectangular shape, for example, as shown in
The reception surface 21a of the receiver 21 may be formed in a circular shape as shown for example in
The area of the reception surface 21a may be, for example, not more than (6×λ)2.
In this case, the length 11 of one side of the square reception surface 21a, the length 12 of the short side of the rectangular reception surface 21a, the length 13 of the diameter of the circular reception surface 21a, and the like, are preferably not more than (6×λ).
Also, the area of the reception surface 21a may be, for example, not more than (4×λ)2. In this case, the length 11 of one side of the square reception surface 21a, the length 12 of the short side of the rectangular reception surface 21a, the length 13 of the diameter of the circular reception surface 21a, and the like, are preferably not more than (4×λ).
Furthermore, the area of the reception surface 21a may be, for example, not more than (2×λ)2. In this case, the length 11 of one side of the square reception surface 21a, the length 12 of the short side of the rectangular reception surface 21a, the length 13 of the diameter of the circular reception surface 21a, and the like, are preferably not more than (2×λ).
As shown in
In this embodiment, the plurality of receivers 21 are arranged spaced apart from each other, as shown in
In this embodiment, the resin 22 integrally fixes the plurality of receivers 21.
The reception unit 20 of this embodiment further includes an FET substrate 23. The FET substrate 23 outputs a received signal corresponding to the ultrasonic beam W received by the receivers 21, to the outside. The plurality of receivers 21 are integrally provided on the FET substrate 23. In
The reception unit 20 of this embodiment further includes a partition wall portion 24. The partition wall portion 24 extends in a direction away from the reception surfaces 21a of the receivers 21 (Z-axis positive direction), and partitions the space above the plurality of reception surfaces 21a for each reception surface 21a. The partition wall portion 24 forms a plurality of cylindrical bodies 25 extending in the Z-axis positive direction from the periphery of each reception surface 21a.
For example, as shown in
As shown in
In the following description, the tip in the extension direction (Y-axis negative direction) of the joint portion 103 with respect to the non-joint portion 105, is called an end portion 103A of the joint portion 103 (the subject 100).
As shown in
In the configuration described above, the transmitter 10 and the receiver 21 may be arranged, for example, so as to protrude to the outside (Y-axis negative direction side) from the end portion 103A of the joint portion 103 (subject 100). In this case, the ultrasonic beam W transmitted or received by the part of the transmitter 10 or the receiver 21 protruding from the end portion 103A, may be ignored in the signal processing. As a result, the state in which the transmitter 10 and the receiver 21 protrude outward from the end portion 103A of the joint portion 103 can be regarded as substantially equivalent to the state in which the transmitter 10 and the receiver 21 are located further inside (the Y axis positive direction side) than the end portion 103A of the joint portion 103.
Also, in the configuration described above, the direction in which the joint portion 103 extends with respect to the non-joint portion 105, does not have to be strictly perpendicular to the transmission direction of the ultrasonic beam W. Because of this, the transmitter 10 and the receivers 21 may be positioned inside with respect to the end portion 103A of the joint portion 103 (the subject 100) in a crossing direction that intersects the transmission direction of the ultrasonic beam W (mainly the Z-axis negative direction), for example.
As shown in
The storage unit 30 stores, as a reference waveform, the waveform of the ultrasonic beam W when it is received by the receivers 21 after having transmitted through a reference subject in which the subject 100 has no defect 104 (see
The determination unit 40 determines the presence or absence of the defect 104 in the inspection subject 100, based on the phase of the waveform to be inspected, which is the waveform of the ultrasonic beam W received by the receiver 21 having transmitted through the inspection subject (that is, the subject 100) which is to be inspected for the presence or absence of the defect 104, and the phase of the reference waveform stored in the storage unit 30.
The output unit 50 outputs the result determined by the determination unit 40, to a display device or the like.
An example of the method by which the determination unit 40 determines whether or not there is a defect 104, will be described below.
First, the determination unit 40 calculates a correlation value between the phase of the reference waveform stored in the storage unit 30, and the phase of the waveform to be inspected. The correlation value is a value obtained by integrating a product of the reference waveform and the waveform to be inspected. After that, the determination unit 40 determines the presence or absence of the defect 104 in the inspection subject 100, based on the correlation value. Specifically, when the correlation value is high, the determination unit 40 determines that the inspection subject 100 does not have the defect 104, and when the correlation value is low, the determination unit 40 determines that the inspection subject 100 has the defect 104.
As described above, in the ultrasonic inspection device 1 of the present embodiment, the area of the reception surface 21a of each receiver 21 that receives the ultrasonic beam W transmitted from the transmitter 10, is set to not more than (10×λ)2, and the area of the reception surface 21a is sufficiently small. Thereby, the defect 104 in the subject 100 can be detected highly precisely.
Also, by arranging a plurality of receivers 21 having small reception surfaces 21a in an array, the total area of the reception surfaces 21a can be increased. As a result, even if the area of the subject 100 to be inspected is large, a defect 104 in the subject 100 can be inspected highly precisely and in a short time.
In addition, in the ultrasonic inspection device 1 of the present embodiment, by setting the length 11 of one side of the square reception surface 21a, or the length 13 of the diameter of the circular reception surface 21a to not more than (2×λ), the area of the reception surface 21a can be set to not more than (2×λ)2.
In addition, by making the length 12 of the short side of the rectangular reception surface 21a smaller than (10×λ), while the area of the reception surface 21a is set to be not more than (10×λ)2, the length of the long side of the rectangular reception surface 21a can be allowed to exceed (10×λ).
Also, in the ultrasonic inspection device 1 of the present embodiment, the plurality of receivers 21 are arranged spaced apart from each other. Because of this, it is possible to prevent the sound pressure of the ultrasonic beam W received by a predetermined receiver 21 from being transmitted to another adjacent receiver 21. That is, it is possible to acoustically insulate between the adjacent receivers 21. Therefore, physical crosstalk between the adjacent receivers 21 can be reduced.
Further, in the ultrasonic inspection device 1 of the present embodiment, the resin 22 having acoustic characteristics different from those of the receivers 21 is interposed between the adjacent receivers 21. Because of this, even if the interval between adjacent receivers 21 is reduced, physical crosstalk between adjacent receivers 21 can be more effectively reduced. Therefore, it is possible to inspect the defect 104 in the subject 100 with more precision. Moreover, when the resin 22 is interposed between the receivers 21, the resin 22 can also be used to integrally fix the plurality of receivers 21.
Even if an air layer is interposed between the adjacent receivers 21, the same effect as described above can be obtained because the air layer and the receivers 21 have different acoustic characteristics.
In addition, in the ultrasonic inspection device 1 of the present embodiment, the determination unit 40 calculates a correlation value between a phase of the reference waveform stored in the storage unit 30, and a phase of the waveform to be inspected, and determines the presence or absence of a defect 104 in the inspection subject 100 based on the correlation value. Because of this, even if the size of the defect 104 in the inspection subject 100 is equal to or smaller than the size of the receiver 21 (reception surface 21a), the defect 104 can be detected. This point will be described below.
The determination unit 40 can determine whether or not the phase of the waveform to be inspected matches the phase of the reference waveform, by calculating the correlation value. Then, when the phase of the waveform to be inspected matches the phase of the reference waveform, the determination unit 40 can determine that there is no defect 104 in the inspection subject 100. On the other hand, when the phase of the reference waveform and the phase of the waveform to be inspected are out of phase, then as shown in
As described above, the ultrasonic inspection device 1 of the present embodiment can detect defects 104 that are equal to or smaller than the size of the receiver 21. That is, the performance for detecting the defect 104 can be improved.
In addition, in the ultrasonic inspection device 1 of the present embodiment, at least one of the transmitter 10 and the receiver 21 is located inside the end portion 103A of the subject 100 by at least the length of the wavelength of the ultrasonic beam W, in the crossing direction (for example, the Y-axis direction) that intersects the transmission direction (Z-axis direction) of the ultrasonic beam W. Because of this, as shown in
In addition, in the ultrasonic inspection device 1 of the present embodiment, since the plurality of receivers 21 are integrally provided on the FET substrate 23, it is possible to suppress deterioration in the sensitivity of the ultrasonic inspection device 1.
To explain this point, when the size of the reception surface 21a of the receiver 21 becomes smaller, the intensity (amplitude) of the ultrasonic beam W received by the receiver 21 becomes smaller. Therefore, if the receiver 21 and the FET substrate 23 are formed separately and connected to each other by electrical wiring, the sensitivity will be lowered due to electrical loss. On the other hand, by integrally providing the receiver 21 with the FET substrate 23, the above electric wiring can be eliminated or shortened. Thereby, it is possible to suppress a decrease in sensitivity due to electrical loss.
In addition, the ultrasonic inspection device 1 of this embodiment includes the partition wall portion 24 that partitions the spaces above the plurality of reception surfaces 21a for each of the reception surfaces 21a. The partition wall portion 24 forms cylindrical bodies 25 extending in a direction away from each reception surface 21a. This can further reduce physical crosstalk between the adjacent receivers 21 (reception surfaces 21a). Further, by utilizing the cylindrical bodies 25 formed by the partition wall portion 24 as resonance tubes, the sensitivity of the ultrasonic beam W received by the receivers 21 (reception surfaces 21a) can be improved.
Moreover, the ultrasonic inspection device 1 of the present embodiment may include a lid portion 26 that covers the opening at the tip of the partition wall portion 24 (cylindrical bodies 25) in the extending direction (Z-axis positive direction) as illustrated in
Although the present disclosure has been described in detail above, the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present disclosure.
In the present disclosure, the determination unit 40 may determine the presence or absence of the defect 104 by a method different from the above embodiment. For example, when the phase of the waveform to be inspected does not include a phase different from the phase of the reference waveform (the waveform when there is no defect 104) stored in the storage unit 30 (that is, when the phase of the waveform to be inspected is not different from the phase of the reference waveform stored in the storage unit 30), the determination unit 40 may determine that the inspection subject 100 does not have the defect 104, and when the phase of the waveform to be inspected includes a phase different from the phase of the reference waveform (that is, when the phase of the waveform to be inspected is different from the phase of the reference waveform), the determination unit 40 may determine that the inspection subject 100 has the defect 104.
When the determination unit 40 determines the presence or absence of the defect 104 as described above, even if the size of the defect 104 in the inspection subject 100 is equal to or smaller than the size of the receiver 21 (reception surface 21a), the defect 104 can be detected. This point will be described below.
The fact that the phase of the waveform to be inspected includes a different phase (specific phase) from the phase of the reference waveform, means that the ultrasonic beam W2 reaches the receiver 21 after being diffracted at the periphery of the small-sized defect 104, as illustrated in
In the present disclosure, the storage unit 30 may store for example, the defective subject 100 as a reference subject, and store the waveform of the ultrasonic beam W received by the receiver 21 having transmitted through the defective portion of the reference subject, as the reference waveform. In this case, when the determination unit 40 determines the presence or absence of a defect by calculating the correlation value between the phase of the reference waveform and the phase of the waveform to be inspected, the determination unit 40 determines that the inspection subject 100 has the defect 104 when the correlation value is high. Further, regarding the determination unit 40, when the correlation value is low, the determination unit 40 determines that the inspection subject 100 does not have the defect 104.
Moreover, in the case where the reference waveform is a waveform that has passed through a defect portion, then when the determination unit 40 determines the presence or absence of a defect based on whether the phase of the waveform to be inspected includes a phase different from the phase of the reference waveform, the determination unit 40 determines that the inspection subject 100 has the defect 104 when the phase of the waveform to be inspected does not include a phase different from the phase of the reference waveform. Further, in the case where the phase of the waveform to be inspected includes a phase different from the phase of the reference waveform, the determination unit 40 determines that there is no defect 104 in the inspection subject 100.
In the present disclosure, the transmission surface 10a of the transmitter 10 may be a flat surface as shown in
In this case, the plurality of receivers 21 are arranged in a matrix corresponding to the planar ultrasonic beam W described above. That is, the plurality of receivers 21 are aligned in two directions (X-axis direction and Y-axis direction) orthogonal to the Z-axis direction. In
By arranging the receivers 21 having a small size of the reception surface 21a (the area of the reception surface 21a is not more than (2×λ)2) in a matrix, the total area of the reception surface 21a can be increased as in the above embodiment. As a result, even if the area of the subject 100 to be inspected is large, a defect 104 in the subject 100 can be inspected highly precisely and in a short time.
In the present disclosure, the plurality of receivers 21 are not limited to being arranged in a matrix form in which they are arranged vertically and horizontally without gaps, or arranged in an array form in which they are arranged in a linear direction without gaps, and may be arranged at least according to a predetermined pattern. The plurality of receivers 21 may be arranged in a pattern (for example, a lattice pattern or a checkered pattern) obtained for example by removing the receivers 21 from a matrix arranged state according to a predetermined rule. Moreover, the plurality of receivers 21 may be arranged in a line along a curved line (for example, a spiral). Further, the plurality of receivers 21 may be arranged in a pattern obtained by removing the receivers 21 according to a predetermined rule, from a state for example in which the plurality of receivers 21 are arranged in rows without gaps (for example, a pattern in which units composed of two receivers 21 are arranged in rows with a gap).
In the present disclosure, the transmitter 10 may transmit the ultrasonic beam W so as to spread in a fan-like or spherical shape as it moves away from the transmission surface 10a of the transmitter 10, for example.
In the present disclosure, as described above, the determination unit 40 that determines the presence or absence of defects in the inspection subject 100, is not limited to making determinations based on the relationship between the phase of the reference waveform and the phase of the waveform to be inspected. The determination unit 40 may perform determination, for example, based on the relationship between the shape of the reference waveform and the shape of the waveform to be inspected. As a specific example, the determination unit 40 may determine the presence or absence of defects based on a difference in shape between the reference waveform and the waveform to be inspected. That is, the determination unit 40 of the present disclosure may determine the presence or absence of a defect based on a relationship between the reference waveform and the waveform to be inspected.
The ultrasonic inspection device of the present disclosure may not include the storage unit 30 for storing reference waveforms, for example. In this case, in the ultrasonic inspection device, for example, ultrasonic waves are transmitted to the subject 100 to obtain a waveform to be inspected, and at the same time, ultrasonic waves are also transmitted to a separately prepared reference subject to generate a reference waveform, and these reference waveforms and the waveform to be inspected may be compared.
According to the present disclosure, even if the area of the subject to be inspected by the ultrasonic inspection device is large, defects in the subject can be inspected highly precisely and in a short time.
Number | Date | Country | Kind |
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2021-080200 | May 2021 | JP | national |
The present application is a continuation application of International Application No. PCT/JP2021/029156, filed Aug. 5, 2021, which claims priority to JP Patent Application No. 2021-080200, filed May 11, 2021. The contents of these applications are incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/JP2021/029156 | Aug 2021 | US |
Child | 18503264 | US |