Ultrasonic inspection device and ultrasonic reception unit

Abstract

The purpose of the present disclosure is to provide an ultrasonic inspection device capable of improving defect detection accuracy as a result of a reception surface being caused to selectively receive ultrasonic waves within a range strongly influenced by a defect. An ultrasonic inspection device 1 according to one aspect of the present disclosure receives, on a reception surface 21a, an ultrasonic wave U incident on a test object 100 and inspects the quality of the test object 100. The ultrasonic inspection device 1 comprises a window part 12 between the test object 100 and the reception surface 21a. If the wavelength of the ultrasonic wave U is defined as λ [mm] and the maximum distance between the test object 100 and the opening edge 12a of the window part 12 in the traveling direction of the ultrasonic wave U is defined as Zmax [mm], the opening width W [mm] of the window part 12 satisfies formula (1).　(1): W ≤ 0.2Zmax (4.1λ + 1.4) + λ

Description

Ultrasound examination equipment and ultrasound receiving unit

[0001] This disclosure relates to an ultrasound inspection apparatus and an ultrasound receiving unit.

[0002] An ultrasound examination device is known that transmits ultrasound waves to a subject to check the quality of that subject (see Patent Document 1).

[0003] International Publication No. 2022 / 239265

[0004] Patent Document 1 describes an ultrasonic inspection device that transmits an ultrasonic beam to the joint portion of a specimen and receives the ultrasonic beam that has passed through the joint portion on a receiving surface to inspect for defects in the joint portion. Patent Document 1 describes that when the wavelength of the ultrasonic beam is λ, the area of ​​the receiving surface is (10 × λ) ２ The following steps are required:

[0005] Patent Document 1 describes that by controlling the area of ​​the receiving surface, defect inspection can be performed with high accuracy and in a short time.

[0006] On the other hand, if a defect is present in the subject, the propagation path of the ultrasound transmitted to the subject changes due to the effects of diffraction and other factors. The inventors have discovered that there is a range of ultrasound waves incident on a defect in the subject that is suitable for detecting the defect.

[0007] One aspect of this disclosure aims to provide an ultrasonic inspection device that can improve the accuracy of defect detection by selectively receiving ultrasonic waves in a range strongly affected by defects on the receiving surface.

[0008] An ultrasonic inspection apparatus according to one aspect of the present disclosure is an ultrasonic inspection apparatus that receives ultrasonic waves incident on a subject on a receiving surface and inspects the quality of the subject, wherein a window is provided between the subject and the receiving surface, the wavelength of the ultrasonic waves is λ [mm], and the maximum distance between the subject and the opening edge of the window in the direction of propagation of the ultrasonic waves is Z ｍａｘ When set to [mm], the opening width W [mm] of the window portion satisfies the following formula (1): W ≤ 0.2Z ｍａｘ (4.1λ+1.4)+λ...(1)

[0009] Figure 1 is a schematic cross-sectional view showing an ultrasonic inspection apparatus according to the first embodiment of this disclosure. Figure 2 is a schematic view of the ultrasonic inspection apparatus of Figure 1 as seen from line II-II. Figure 3 is a schematic cross-sectional view illustrating the propagation path of ultrasound that has passed through a specimen in the ultrasonic inspection apparatus of Figure 1. Figure 4 is a diagram showing an example of the sound pressure distribution of ultrasound that has passed around a defect in the ultrasonic inspection apparatus of this disclosure. Figure 5 is a graph showing the relationship between the distance from the defect edge and the sound pressure of ultrasound that has passed around a defect in the ultrasonic inspection apparatus of this disclosure. Figure 6 is a schematic diagram for illustrating the range in which the sound pressure distribution of ultrasound becomes non-uniform in the ultrasonic inspection apparatus of this disclosure. Figure 7 is a graph showing the relationship between the range in which the sound pressure distribution of ultrasound becomes non-uniform and the wavelength of ultrasound in the ultrasonic inspection apparatus of this disclosure. Figure 8 is a schematic cross-sectional view showing an ultrasonic inspection apparatus according to the second embodiment of this disclosure. Figure 9 is a schematic view of the ultrasonic inspection apparatus of Figure 8 as seen from line IX-IX, illustrating the direction of movement of the specimen.

[0010] (1) An ultrasonic inspection apparatus according to one aspect of the present disclosure is an ultrasonic inspection apparatus that receives ultrasonic waves incident on a subject on a receiving surface and inspects the quality of the subject, wherein a window is provided between the subject and the receiving surface, the wavelength of the ultrasonic waves is λ [mm], and the maximum distance between the subject and the opening edge of the window in the direction of propagation of the ultrasonic waves is Z ｍａｘ When set to [mm], the opening width W [mm] of the window portion satisfies the following formula (1): W ≤ 0.2Z ｍａｘ (4.1λ+1.4)+λ...(1)

[0011] (2) In (1) above, a passage is provided in front of the window portion through which the subject passes, so as to cross the window portion, and the maximum distance Z ｍａｘ This may be determined by the passage width relative to the opening edge.

[0012] (3) In (1) or (2) above, the opening width W may be the minimum opening width of the window portion.

[0013] (4) In any of (1) to (3) above, a transport mechanism is further provided for transporting the subject in front of the window so as to cross the window, and the opening width W may be the width in the transport direction of the subject.

[0014] (5) In (4) above, a plurality of receiving surfaces may be provided, which are arranged in a row in a direction perpendicular to the transport direction of the subject.

[0015] (6) In any of (1) to (5) above, an ultrasonic transmitting unit is provided that transmits ultrasonic waves toward the subject, and the ultrasonic waves transmitted from the ultrasonic transmitting unit may be plane waves.

[0016] (7) Another embodiment of the present disclosure is an ultrasonic receiving unit having a receiving surface for receiving ultrasonic waves incident on a subject, wherein the receiving surface is provided with a window in front of it, the wavelength of the ultrasonic waves is λ [mm], and the maximum distance between the subject and the opening edge of the window in the direction of propagation of the ultrasonic waves is Z ｍａｘ When set to [mm], the opening width W [mm] of the window portion satisfies the following formula (1): W ≤ 0.2Z ｍａｘ (4.1λ+1.4)+λ...(1)

[0017] [Effects of this Disclosure] An ultrasonic inspection apparatus according to one aspect of this disclosure can improve the accuracy of defect detection by selectively receiving ultrasonic waves in the range strongly affected by defects on the receiving surface.

[0018] The embodiments of this disclosure will be described in detail below, with reference to the drawings as appropriate. Note that, regarding the numerical values ​​described herein, it is possible to adopt only one of the upper or lower limits, or to combine the upper and lower limits as desired. In this specification, all possible numerical ranges are described as suitable ranges. Furthermore, each figure is schematic and may not correspond to actual dimensions, proportions, etc. In this disclosure, the designations "First" and "Second" are for distinguishing the components to which they are attached and do not limit the number, order, priority, etc.

[0019] [First Embodiment] <Ultrasonic Inspection Device> The ultrasonic inspection device 1 shown in FIGS. 1 and 2 receives ultrasonic waves incident on a subject at the reception surface 21a and inspects the quality of the subject. The ultrasonic inspection device 1 includes a window portion 12 between the subject and the reception surface 21a. As shown in FIG. 3, the ultrasonic inspection device 1 has the wavelength of the ultrasonic wave U as λ [mm], and the maximum distance between the subject 100 and the opening edge 12a of the window portion 12 in the traveling direction of the ultrasonic wave U as Z ｍａｘ [mm], the opening width W [mm] of the window portion 12 satisfies the following formula (1). W ≤ 0.2Z ｍａｘ (4.1λ + 1.4) + λ... (1)

[0020] By satisfying the formula (1), the ultrasonic inspection device 1 can selectively receive the ultrasonic wave U in the range strongly affected by the defect 110 at the reception surface 21a, thereby improving the detection accuracy of the defect 110. More specifically, the ultrasonic inspection device 1 can improve the detection accuracy of the defect 110 by selectively passing the ultrasonic wave U in the range strongly affected by the defect 110 through the window portion 12.

[0021] Referring to FIGS. 4 to 7, the reason why the ultrasonic inspection device 1 can improve the detection accuracy of the defect 110 by satisfying the formula (1) will be described.

[0022] If the subject 100 has a defect 110, the ultrasonic wave U transmitted towards the defect 110 will be blocked by the defect 110 or will bend around the defect 110 and interfere. As a result, the sound pressure of the ultrasonic wave U that has passed around the defect 110 will be non-uniform. Figure 4 shows the simulation results of the sound pressure distribution of the ultrasonic wave U that has passed around the defect 110. Figure 4 shows the relationship between the distance [mm] from the defect 110 in a direction perpendicular to the propagation direction of the plane wave of the ultrasonic wave U that has passed around the defect 110 and the absolute value of the sound pressure [Pa] when an ultrasonic wave U (plane wave) is transmitted towards the defect 110. In Figure 4, an 800 kHz ultrasonic wave U is transmitted towards the defect 110. In Figure 4, the horizontal axis shows the distance X [mm] relative to the center of the defect 110 in a direction perpendicular to the propagation direction of the ultrasonic wave U, and the vertical axis shows the propagation distance Z1 [mm] of the ultrasonic wave U relative to the defect 110 in the propagation direction of the ultrasonic wave U. As can be seen from Figure 4, the ultrasonic waves U are blocked by the defect 110, and as a result, the region with the lowest sound pressure (lowest sound pressure region O) is formed directly behind the defect 110. However, as shown in Figure 4, a portion of the lowest sound pressure region O may have a high sound pressure area. This area is formed by the reinforcement of ultrasonic waves U diffracted around the defect 110, and can be said to be a portion that appears specifically in the lowest sound pressure region O. On the other hand, around the lowest sound pressure region O, a region with uneven sound pressure (uneven sound pressure region A1) is formed as the ultrasonic waves U wrap around the defect 110.

[0023] Figure 5 is a graph showing the sound pressure for each size in the sound pressure non-uniformity region A1, obtained by performing the simulation in Figure 4 while varying the size of the defect 110. The vertical axis in Figure 5 shows the absolute sound pressure [Pa] at a position 10 mm away from the defect in the Z-axis direction (plane wave transmission direction). That is, the vertical axis shows the absolute sound pressure [Pa] at a propagation distance of 10 [mm] (Z1 = 0 [mm]) of the ultrasonic U relative to the defect 110 in Figure 4. As can be seen from Figure 5, regardless of the size of the defect 110, the sound pressure non-uniformity region A1 has a first low sound pressure region A1a (illustrated in Figure 5 for a defect with a diameter of 5 mm) that is continuous from the edge of the defect 110 (the edge of the lowest sound pressure region O), and a second low sound pressure region A1b (illustrated in Figure 5 for a defect with a diameter of 5 mm) that is continuous from the first low sound pressure region A1a. The first low sound pressure region A1a is the region where the sound pressure is 1.0 Pa or less from the edge of the defect 110 until it reaches the reference sound pressure (sound pressure 1.0 Pa). The second low sound pressure region A1b is the region outside the first low sound pressure region A1a where the sound pressure drops again to below the reference sound pressure and then reaches the reference sound pressure. Furthermore, as can be seen from Figure 5, outside the second low sound pressure region A1b, there is a region where the sound pressure changes around the reference sound pressure and is relatively uniform. This region with relatively uniform sound pressure is located outside the range that is strongly affected by the defect 110, or in other words, it is a region that does not contain defect information and is unnecessary for defect inspection. From Figure 5, in order to detect defects 110 in the specimen 100 with high accuracy in the ultrasonic inspection apparatus 1, it is considered effective to propagate ultrasonic waves U in a region that selectively includes the lowest sound pressure region O, the first low sound pressure region A1a, and the second low sound pressure region A1b, either directly or via the support 22, to the receiving piezoelectric element 21. That is, in this disclosure, ultrasonic waves U may be propagated directly to the receiving piezoelectric element 21, or a portion of them may be propagated indirectly to the receiving piezoelectric element 21 via the support 22.

[0024] Figure 6 shows the result of Figure 5 applied to the opening width W of the window section 12. As shown in Figure 6, it is desirable that the opening width W be based on the size that allows the first low sound pressure region A1a and the second low sound pressure region A1b to be positioned on both sides of the lowest sound pressure region O.

[0025] Figure 7 shows the maximum distance Z between the subject 100 and the opening edge 12a of the window 12 in the ultrasound examination apparatus 1. ｍａｘ This shows the relationship between the size and wavelength of the first low-sound-pressure region A1a and the second low-sound-pressure region A1b when the diameter is 10 mm. From Figure 7, it can be seen that the total length (A1a + A1b) of the first low-sound-pressure region A1a and the second low-sound-pressure region A1b, with respect to the edge of the defect 110, can be linearly approximated by 4.1 × λ [mm] + 1.4. Here, as can also be seen from Figure 4, the total length (A1a + A1b) is considered to be roughly proportional to the propagation distance Z1 [mm] in the direction of propagation of the ultrasonic wave U. Therefore, the preferred opening width W [mm] of the opening of the window portion 12 is W ≤ 2 × (A1a + A1b) + 2d, where W ≤ 2 × Z ｍａｘ [mm] / 10 × (4.1 × λ [mm] + 1.4) + 2d. And, as a detectable defect size, the diameter of defect 110 is considered to be approximately λ [mm], so if we set 2d = λ [mm], we obtain the above equation (1). As an example, if the frequency in the above equation (1) is 800 kHz (speed of sound 340 m / s), then λ = 0.425 mm, and Z ｍａｘ If we assume = 5 mm, then W ≤ 0.2 × 5(4.1 × 0.425 + 1.4) + 0.425 ≈ 3.57.

[0026] [Subject] The ultrasonic inspection device 1 can inspect the quality of various subjects 100. The subject 100 is not particularly limited, but may be, for example, a sealed container containing contents. The contents are not particularly limited, but may include food and beverages, pharmaceuticals, medical supplies, chemicals, etc. The area to be inspected (the area to be subjected to ultrasonic inspection) on the subject 100 may be the opening where the contents are contained. Examples of the area to be inspected include a heat-sealed portion where the opening is heat-welded by heating and applying pressure, or an ultrasonic-sealed portion where the opening is welded using ultrasound. The subject 100 may be, for example, a bag such as a pouch having the heat-sealed portion or the ultrasonic-sealed portion. Defects 110 with a diameter of about 5 mm or less may be formed on the area to be inspected, and such minute defects 110 may cause misinspection. In this regard, the ultrasonic inspection device 1 can detect such minute defects 110 with high accuracy. Furthermore, if the subject 100 is the aforementioned pouch, the ultrasound examination device 1 may be configured as a pouch examination device.

[0027] [Ultrasound] The wavelength of the ultrasonic wave U used in the ultrasonic inspection device 1 is not particularly limited. The lower limit of the wavelength of the ultrasonic wave U may be 0.07 mm or 0.17 mm from the viewpoint of propagation attenuation. The upper limit of the wavelength of the ultrasonic wave U may be 8.5 mm or 3.4 mm from the viewpoint of resolution.

[0028] An example of the specific configuration of the ultrasound inspection apparatus 1 is described below. The ultrasound inspection apparatus 1 comprises an ultrasonic transmitting unit 13 that transmits ultrasonic waves U toward a subject 100, an ultrasonic receiving unit 11 positioned opposite the ultrasonic transmitting unit 13, and a window unit 12 positioned between the ultrasonic transmitting unit 13 and the ultrasonic receiving unit 11. The ultrasound inspection apparatus 1 may also include a passage 14 formed in the space between the ultrasonic transmitting unit 13 and the window unit 12, and a transport mechanism (not shown) that transports the subject 100 across the window unit 12 in front of the window unit 12 (in the direction facing the passage). The ultrasonic transmitting unit 13, the ultrasonic receiving unit 11, and the window unit 12 may be positioned in a fluid such as air or nitrogen.

[0029] The ultrasonic inspection device 1 is configured to detect defects 110 in the subject 100 by transmitting ultrasonic waves U from the ultrasonic transmitting unit 13 and allowing these ultrasonic waves U to pass through the subject 100 and be received by the receiving surface 21a. In other words, the ultrasonic inspection device 1 is a transmission-type ultrasonic inspection device.

[0030] (Ultrasonic Transmitter) The ultrasonic transmitter 13 includes a piezoelectric element (transmitting piezoelectric element). The ultrasonic transmitter 13 is capable of transmitting ultrasonic waves based on the vibration of the transmitting piezoelectric element. The transmitting piezoelectric element has a transmitting surface 13a that transmits ultrasonic waves U. The ultrasonic transmitter 13 transmits a plane wave toward the receiving surface 21a. That is, in the ultrasonic inspection apparatus 1, the ultrasonic waves U transmitted from the ultrasonic transmitter 13 are plane waves. The transmitting surface 13a may be formed in a planar shape.

[0031] The ultrasonic inspection device 1 is designed so that the ultrasonic waves U transmitted from the ultrasonic transmitting unit 13 are plane waves, thereby satisfying equation (1), and making it easier to selectively receive ultrasonic waves U in the range strongly affected by defects (a range that selectively includes the aforementioned lowest sound pressure region O, the first low sound pressure region A1a, and the second low sound pressure region A1b) on the receiving surface 21a.

[0032] (Ultrasonic Receiver Unit) The ultrasonic receiver unit 11 includes a piezoelectric element (piezoelectric element 21 for reception). More specifically, the ultrasonic receiver unit 11 has a piezoelectric element 21 for reception and a support 22 that supports the piezoelectric element 21 for reception. The reception surface 21a is provided on a surface of the piezoelectric element 21 for reception that faces the transmission surface 13a. The ultrasonic receiver unit 11 converts the ultrasonic wave U received by the piezoelectric element 21 for reception into an analog electrical signal.

[0033] (Window Portion) The window portion 12 covers the periphery of the reception surface 21a in front of the reception surface 21a so that the reception surface 21a and the transmission surface 13a directly face each other with the test object 100 sandwiched therebetween. The window portion 12 may be formed, for example, on a plate material 23 disposed between the reception surface 21a and the transmission surface 13a. The plate material 23 is, for example, spaced apart from the transmission surface 13a and the reception surface 21a and is disposed parallel to the transmission surface 13a and the reception surface 21a. The window portion 12 is, for example, a through-hole that penetrates in the thickness direction of the plate material 23.

[0034] The window portion 12 selectively allows the ultrasonic wave U transmitted through the test object 100 to pass toward the reception surface 13a. As described above, the window portion 12 is set such that the opening width W satisfies the above formula (1). The opening width W is the width of a portion that overlaps the reception surface 21a in a plan view (view in the normal direction of the reception surface 21a; view in the Z-axis direction in FIG. 2).

[0035] The opening width W may be the minimum opening width of the window portion 12. In other words, the opening width W may be the minimum width in a portion that overlaps the reception surface 21a in a plan view. According to this configuration, it is possible to easily form the window portion 12 in accordance with the specifications of the apparatus and the like, and to easily improve the inspection accuracy of the test object 100.

[0036] Further, the opening width W may be the width in the conveyance direction of the test object 100 by the conveyance mechanism (width in a direction parallel to the conveyance direction). By including the conveyance mechanism, the ultrasonic inspection apparatus 1 can efficiently inspect the presence or absence of defects 110 in the test object 100 while continuously feeding a plurality of test objects 100 between the transmission surface 13a and the reception surface 21a. At this time, by making the opening width W the width in the conveyance direction, it is possible to easily achieve both an improvement in the inspection efficiency of the defect 110 and an improvement in the inspection accuracy.

[0037] As described above, the upper limit of the opening width W of the window portion 12 is determined by the above formula (1). On the other hand, as the lower limit of the opening width W of the window portion 12, for example, it may be the wavelength λ [mm] of the ultrasonic wave U. According to this configuration, it becomes easier to selectively receive the ultrasonic wave U in the region where the sound pressure is low corresponding to the aforementioned lowest sound pressure region O by the receiving surface 21a. As a result, the detection accuracy of the defect 110 in the ultrasonic inspection device 1 can be improved.

[0038] The shape of the window portion 12 can be designed based on, for example, the specifications of the entire device. The shape of the window portion 12 is not particularly limited, and examples include a rectangular shape, a circular shape, an elliptical shape, an oval shape (a shape in which the ends of two opposite sides are connected by an arc), and a polygonal shape. Note that each of the above shapes includes not only the shape in a strict sense, but also a shape in which, for example, the corners are rounded, or an arbitrary side has irregularities or is curved. The opening width W may be the width of the short side when the window portion 12 is rectangular, the width of the diameter when the window portion 12 is circular, the width of the short axis when the window portion 12 is elliptical or oval, or an arbitrary width passing through the center when the window portion 12 is polygonal.

[0039] The inner peripheral surface of the window portion 12 may be formed perpendicular to the receiving surface 21a, for example, or may be narrowed toward the receiving surface 21a side as shown in FIG. 1. When the inner peripheral surface of the window portion 12 is narrowed toward the receiving surface 21a side, the opening width W of the window portion 12 means the width at the end on the receiving surface 21a side. That is, the opening width W of the window portion 12 means the opening width W in a plan view.

[0040] (Passage) The ultrasonic inspection device 1 is provided with a passage 14 through which the test object 100 passes across the window portion 12 in front of the window portion 12. The passage 14 includes the space between the transmitting surface 13a and the window portion 12. More specifically, a part of the passage 14 includes the propagation path of the ultrasonic wave U from the transmitting surface 13a to the window portion 12 after the ultrasonic wave U transmitted from the transmitting surface 13a passes through the test object 100. The passage 14 may be defined by, for example, the space between a housing (not shown) in which the ultrasonic wave transmitting unit 13 is arranged and the plate material 23 provided with the window portion 12.

[0041] In the ultrasound examination apparatus 1, the maximum distance Z between the subject 100 and the opening edge 12a of the window portion 12 in the direction of propagation of the ultrasound U (negative direction in the Z axis direction in Figure 1) is ｍａｘ The maximum distance Z may be determined by the passage width Wa with respect to the opening edge 12a. In the ultrasonic inspection apparatus 1, the opening width W of the window portion 12 is controlled to satisfy the above formula (1). ｍａｘ By defining the passage width Wa with respect to the opening edge 12a, the ultrasonic waves U in the range excluding the area outside the second low sound pressure region A1b can be easily received on the receiving surface 21a, regardless of where the subject 100 passes through the passage 14. As a result, the detection accuracy of defects 110 in the subject 100 can be improved.

[0042] The upper limit of the passage width Wa, relative to the opening edge 12a, may be, for example, 20 mm or 15 mm. When the passage width Wa is less than or equal to the upper limit, the maximum distance Z between the subject 100 and the opening edge 12a is maintained. ｍａｘ This can be easily approximated by the passage width Wa. On the other hand, the lower limit of the passage width Wa may be, for example, 5 mm or 10 mm, from the viewpoint of allowing the subject 100 to easily pass through the passage 14.

[0043] (Transportation Mechanism) The transport mechanism transports the subjects 100 so that they pass through the passage 14. The transport mechanism includes, for example, a gripping unit for gripping the subjects 100 and a drive unit for driving the gripping unit. The transport mechanism may be provided to transport a plurality of subjects 100 continuously at intervals.

[0044] <Ultrasonic Receiving Unit> An ultrasonic receiving unit according to one aspect of the present disclosure has a receiving surface for receiving ultrasonic waves incident on a subject. The ultrasonic receiving unit is provided with a window portion in front of the receiving surface. The ultrasonic receiving unit has a wavelength of ultrasonic waves as λ [mm] and the maximum distance between the subject and the opening edge of the window portion in the direction of propagation of the ultrasonic waves as Z ｍａｘ When set to [mm], the opening width W [mm] of the window portion satisfies the following formula (1): W ≤ 0.2Z ｍａｘ(4.1λ+1.4)+λ...(1)

[0045] The ultrasonic receiving unit only needs to include the ultrasonic receiving surface and the window portion, and may be, for example, a unit consisting of the ultrasonic receiving section 11 and the plate material 23. In this case, the ultrasonic receiving unit constitutes a part of the ultrasonic inspection apparatus 1 shown in Figure 1.

[0046] The ultrasonic receiving unit, by satisfying formula (1), can selectively receive ultrasonic waves in the range strongly affected by defects on the receiving surface, thereby improving the accuracy of defect detection.

[0047] [Second Embodiment] <Ultrasonic Inspection Apparatus> The ultrasonic inspection apparatus 31 shown in Figures 8 and 9 receives ultrasonic waves incident on a subject 100 with a receiving surface 21a and inspects the quality of the subject 100. The ultrasonic inspection apparatus 31 is provided with a window 42 between the subject 100 and the receiving surface 21a. More specifically, the ultrasonic inspection apparatus 31 includes an ultrasonic transmitting unit 13 that transmits ultrasonic waves toward the subject 100, an ultrasonic receiving unit 41 positioned opposite the ultrasonic transmitting unit 13, a window 42 positioned between the ultrasonic transmitting unit 13 and the ultrasonic receiving unit 41, a passage 14 formed in the space between the ultrasonic transmitting unit 13 and the window 42, and a transport mechanism 43 that transports the subject 100 across the window 42 in front of the window 42 (in the direction facing the passage 14). The ultrasonic inspection device 31 has a wavelength of ultrasound as λ [mm], and the maximum distance between the subject 100 and the opening edge 42a of the window portion 42 in the direction of ultrasound propagation is Z. ｍａｘ When set to [mm], the opening width W [mm] of the window section 42 satisfies the following formula (1): W ≤ 0.2Z ｍａｘ (4.1λ + 1.4) + λ ... (1) The ultrasonic inspection apparatus 31 includes an ultrasonic receiving unit having a receiving surface 21a and a window portion 42. The ultrasonic receiving unit itself is one embodiment of the present disclosure.

[0048] The ultrasonic inspection device 31 and the ultrasonic receiving unit satisfy formula (1) above, thereby selectively receiving ultrasonic waves in the range strongly affected by defects on the receiving surface, and thereby improving the accuracy of defect detection.

[0049] The ultrasonic inspection apparatus 31 is provided with a plurality of receiving surfaces 21a arranged in a row in a direction perpendicular to the transport direction of the subject 100 (the forward direction in the X-axis direction in Figure 9) (the Y-axis direction in Figure 9). The receiving surfaces 21a are provided on the surfaces of the receiving piezoelectric elements 21 that face the ultrasonic transmitting unit 13 (more specifically, the surfaces that face the transmitting surface 13a). The ultrasonic receiving unit 41 may have a plurality of receiving piezoelectric elements 21 arranged in a row with spacing between them, and a support 51 that supports the plurality of receiving piezoelectric elements 21.

[0050] The ultrasonic inspection device 31 includes a window portion 42 formed in front of the plurality of receiving surfaces 21a, spanning across the plurality of receiving surfaces 21a. The window portion 42 is elongated, with its longitudinal direction aligned with the alignment direction of the plurality of receiving surfaces 21a (the Y-axis direction in Figure 9). The window portion 42 may also be rectangular in shape, for example.

[0051] The transport mechanism 43 has a gripping part 43a for gripping the subject 100 and a drive part (not shown) for driving the gripping part 43a. The transport mechanism 43 transports the subject 100 in front of the window part 42 so as to cross the window part 42. The transport mechanism 43 transports multiple subjects 100 continuously with spacing between them in a direction perpendicular to the alignment direction of the multiple receiving surfaces 21a.

[0052] The ultrasonic inspection device 1 can have the same configuration as the ultrasonic inspection device 1 in Figure 1, except that it has multiple receiving surfaces 21a and one window portion 42 is provided for each of the multiple receiving surfaces 21a.

[0053] In the ultrasonic inspection apparatus 31, the window portion 42 is elongated, with the alignment direction of the multiple receiving surfaces 21a being the longitudinal direction. In the ultrasonic inspection apparatus 31, the specimen 100 is transported in the short direction of the window portion 42 by the transport mechanism 43. In this configuration, the opening width W of the window portion 42 may be the width in the transport direction of the specimen 100. With this configuration, ultrasonic waves in the range strongly affected by defects can be easily and selectively received by the multiple receiving surfaces 21a. As a result, the accuracy of defect detection can be easily improved.

[0054] Furthermore, since the ultrasonic inspection device 31 has multiple receiving surfaces 21a aligned in a row in a direction perpendicular to the transport direction of the specimen 100, it is possible to suppress defects from passing straight past the receiving surfaces 21a without crossing in front of them. As a result, the accuracy of defect detection can be easily improved.

[0055] [Other Embodiments] The embodiments described above do not limit the configuration of the present invention. Therefore, the embodiments may omit, substitute, or add components of each part of the embodiments based on the description herein and common technical knowledge, and all such additions should be interpreted as falling within the scope of the present invention.

[0056] In the above embodiment, a configuration was described in which the subject is transported by a transport mechanism so as to cross in front of the window. On the other hand, in this disclosure, the means for positioning the subject in front of the window are not particularly limited. For example, in the ultrasound examination apparatus, the window may be configured to move relative to the subject, or the receiving surface may be configured to move together with the window.

[0057] In this disclosure, the ultrasonic waves transmitted from the ultrasonic transmitting unit are not limited to plane waves.

[0058] In the above embodiment, a configuration was described in which the receiving surface is provided on the surface of the receiving piezoelectric element facing the transmitting surface. However, in this disclosure, the configuration of the receiving surface is not limited to the configuration described in the above embodiment. For example, the receiving surface can also be defined by including the receiving piezoelectric element and a part of the support on which the receiving piezoelectric element is arranged.

[0059] In the above embodiment, a transmission-type ultrasound inspection apparatus was described. However, in this disclosure, the ultrasound inspection apparatus may be a reflection-type apparatus that reflects ultrasound waves transmitted from an ultrasound transmitting unit off the subject and receives the reflected ultrasound waves on a receiving surface.

[0060] 1, 31 Ultrasonic inspection device 11, 41 Ultrasonic receiving unit 12, 42 Window unit 12a, 42a Opening edge 13 Ultrasonic transmitting unit 13a Transmitting surface 14 Passageway 21 Receiving piezoelectric element 21a Receiving surface 22, 51 Support 23 Plate material 43 Transport mechanism 43a Gripping unit 100 Test subject 110 Defect A1 Non-uniform sound pressure region A1a First low sound pressure region A1b Second low sound pressure region O Lowest sound pressure region U Ultrasound W Opening width of window unit Wa Passageway width relative to the opening edge Z ｍａｘ Maximum distance Z1 between the subject and the opening edge of the window in the direction of ultrasound propagation; Propagation distance in the direction of ultrasound propagation.

Claims

1. An ultrasonic inspection apparatus for inspecting the quality of a subject by receiving ultrasonic waves incident on the subject at a receiving surface, wherein a window is provided between the subject and the receiving surface, the wavelength of the ultrasonic waves is λ [mm], and the maximum distance between the subject and the opening edge of the window in the direction of propagation of the ultrasonic waves is Z. ｍａｘ When given [mm], the ultrasonic inspection device has an opening width W [mm] of the window portion that satisfies the following formula (1): W ≤ 0.2Z ｍａｘ (4.1λ+1.4)+λ...(1) 2. A passage is provided in front of the window portion through which the subject passes, so as to cross the window portion, and the maximum distance Z ｍａｘ The ultrasonic inspection apparatus according to claim 1, wherein the width is determined by the passage width with respect to the opening edge.

3. The ultrasonic inspection apparatus according to claim 1, wherein the opening width W is the minimum opening width of the window portion.

4. The ultrasonic inspection apparatus according to claim 1, further comprising a transport mechanism for transporting the subject across the window in front of the window, wherein the opening width W is the width in the transport direction of the subject.

5. The ultrasonic inspection apparatus according to claim 4, comprising a plurality of receiving surfaces arranged in a row in a direction perpendicular to the transport direction of the subject.

6. An ultrasonic inspection apparatus according to any one of claims 1 to 5, comprising an ultrasonic transmitting unit that transmits ultrasonic waves toward the subject, wherein the ultrasonic waves transmitted from the ultrasonic transmitting unit are plane waves.

7. An ultrasonic receiving unit having a receiving surface for receiving ultrasonic waves incident on a subject, wherein a window portion is provided in front of the receiving surface, the wavelength of the ultrasonic waves is λ [mm], and the maximum distance between the subject and the opening edge of the window portion in the direction of propagation of the ultrasonic waves is Z. ｍａｘ When given [mm], the ultrasonic receiving unit whose window opening width W [mm] satisfies the following formula (1): W ≤ 0.2Z ｍａｘ (4.1λ+1.4)+λ...(1)

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