Ultrasonic inspection device, method, and program

Abstract

To provide a data processing technique for an ultrasonic detector that can reliably determine the soundness of a welding state of a connection part of a lap resistance welding.SOLUTION: An ultrasonic inspection device includes: an acquisition unit 15 for acquiring data of echo waves 25 (25a, 25b, 25c) of an ultrasonic wave detector in lap resistance welding of an inspection target body 30 formed by depositing a plurality of tubular materials 35 (351,352); a first detection unit 11 for detecting a first peak in a position which corresponds to a bottom surface 36 of an inspection target body 30 from the echo wave 25; and a determination unit 17 for determining whether the deposition surface of the tubular materials 35 (351,352) is thermally compressed (38) or is melted and solidified (37) on the basis of the echo wave 25.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] An embodiment of the present invention relates to an ultrasonic inspection technique for processing flaw detection data in lap resistance welding. [Background technology]

[0002] Lap resistance welding (such as spot welding) is a technique in which two or more overlapping plate-shaped materials are sandwiched between electrodes, pressure is applied, and an electric current is passed through them, causing the metal in the sandwiched area to melt and solidify due to the resistance heat generated at the contact surface, thereby joining the materials. Ultrasonic flaw detection is widely used to non-destructively inspect the weld condition and presence of welding defects at this fused and solidified joint (commonly known as a nugget).

[0003] Ultrasonic waves have the property of being reflected at interfaces where there is a large difference in acoustic impedance, which indicates how easily the waves propagate. Therefore, at interfaces between overlapping plate-like materials where the acoustic impedance difference is large, ultrasonic waves are reflected without passing through. On the other hand, at interfaces where the plates are joined, the difference in acoustic impedance is small, so ultrasonic waves pass through without reflecting. Therefore, whether or not a sound nugget has been formed is determined by irradiating ultrasonic waves from the surface and determining whether an echo wave from the bottom surface is detected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-315582 Summary of the Invention [Problem to be solved by the invention]

[0005] However, even at interfaces where the difference in acoustic impedance is small and ultrasonic waves can pass through, there are cases where the overlapping surfaces are merely thermocompression-bonded rather than melted and solidified. Joints with widespread thermocompression-bonded interfaces can be said to be in an unsound weld, but it has been difficult to accurately judge this.

[0006] The embodiments of the present invention have been made in consideration of the above circumstances, and have an object to provide an ultrasonic inspection technique that can determine the soundness of the welding state of a lap resistance welded joint with high reliability. [Means for solving the problem]

[0007] In the ultrasonic inspection device according to the embodiment, an acquisition unit acquires data of echo waves of an ultrasonic flaw detection test in lap resistance welding of an object to be inspected in which a plurality of plate-shaped materials are overlapped, a first detection unit detects a first peak from the echo waves at a position corresponding to the bottom surface of the object to be inspected, and a determination unit determines whether the overlapping surfaces of the plate-shaped materials are melted and solidified or thermocompression bonded based on the echo waves. a third detection unit that detects a third peak of the echo wave at a contact surface of the overlapping surfaces of the plate-shaped material; an association unit that associates the echo wave corresponding to each of a plurality of pixels that partition an area in a planar view of the object to be inspected; and an image generation unit that causes the pixel where the first peak is detected to emit a first color and causes the pixel where the third peak is detected to emit a third color. Equipped with When the number of overlapping plate-shaped materials in the test object is three or more, the pixels that emit the third color are further color-coded according to the different contact surfaces. . [Effects of the Invention]

[0008] Embodiments of the present invention provide an ultrasonic inspection technique that can reliably determine the weld integrity of a resistance lap welded joint. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a configuration diagram of an ultrasonic inspection device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of an object to be inspected that is applied to the first embodiment. [Figure 3] Graph showing the detection of echo waves that passed through the melted and solidified portions of the overlapping surfaces. [Figure 4] This is a graph showing the detected echo waves that passed through the thermocompression bonded portion of the overlapping surfaces. [Figure 5] This is a graph showing the echo waves reflected from the contact surface of the overlapping surfaces. [Figure 6] FIG. 10 is a configuration diagram of an ultrasonic inspection apparatus according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a configuration diagram of an ultrasonic inspection device according to a third embodiment of the present invention. [Figure 8](A) A cross-sectional view of an object to be inspected that is applied in the third embodiment, (B) an inspection screen showing the periphery of the contact surface at the welded portion of the object to be inspected, and (C) an inspection screen further showing the periphery of the thermocompression bond. [Figure 9] 3 is a flowchart of an ultrasonic inspection method and an ultrasonic inspection program according to each embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (First embodiment) Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram of an ultrasonic inspection device 10A according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of an object to be inspected 30 used in the first embodiment. As described above, the ultrasonic inspection device 10A includes an acquisition unit 15 that acquires data of echo waves 25 (25a, 25b, 25c) of an ultrasonic flaw detection test performed during lap resistance welding of an object to be inspected 30 in which a plurality of overlapping plate-shaped materials 35 (351, 352) are stacked; a first detection unit 11 that detects first peaks 21 (211, 212, 213...) from the echo waves 25 at positions corresponding to the bottom surface 36 of the object to be inspected 30; and a determination unit 17 that determines, based on the echo waves 25, whether the overlapping surfaces of the plate-shaped materials 35 (351, 352) are melted and solidified 37 or thermocompression bonded 38.

[0011] Lap resistance welding is a technique similar to spot welding, projection welding, seam welding, etc., in which two or more overlapping plate-shaped materials 35 (351, 352) are sandwiched between electrode rods and pressure is applied while an electric current is passed through them, and the resistance heat generated at the contact surface melts and solidifies the metal in the sandwiched portion to join them. Note that the material of the plate-shaped material 35 used in this embodiment includes not only metal but also insulating resin materials, etc. The shape of the plate-shaped material 35 also includes not only a two-dimensional flat plate but also a three-dimensional solid plate.

[0012] The equipment used for ultrasonic flaw detection preferably employs a phased array system in which multiple small piezoelectric elements that transmit and receive ultrasonic waves are arranged two-dimensionally. By transmitting and receiving ultrasonic waves using the arranged multiple piezoelectric elements, ultrasonic flaw detection using this phased array system can acquire data on echo waves 25 at any position on the object under test 30 without moving the array probe.

[0013] Furthermore, this phased array method performs aperture synthesis processing on ultrasonic signals received by multiple piezoelectric elements, thereby obtaining echo waves 25 with excellent detection sensitivity and spatial resolution. Here, aperture synthesis processing is a technique in which the 3D imaging region inside the object 30 is partitioned into meshes, and in each mesh, electrical signals received by all piezoelectric elements are synthesized according to the corresponding propagation time data.

[0014] Furthermore, the ultrasonic flaw detection method is not limited to the phased array method described above, and a monocular method can also be adopted. In the case where the monocular method is adopted, the flaw detection test is performed by scanning the surface of the object under test 30 with a probe.

[0015] Fig. 3 is a graph showing the detection of echo wave 25a that has passed through the melted and solidified portion 37 of the overlapping surfaces. Fig. 4 is a graph showing the detection of echo wave 25b that has passed through the thermocompression bonded portion 38 of the overlapping surfaces. Fig. 5 is a graph showing the detection of echo wave 25c that has been reflected by contact surface 39 of the overlapping surfaces.

[0016] Ultrasonic waves have the property of being reflected at interfaces where there is a large difference in acoustic impedance, which indicates how easily the waves propagate. For this reason, the non-bonded contact surface 39 of the interface between the overlapping plate-shaped materials 35 (351, 352) is reflected without passing through because there is an air layer between them and the difference in acoustic impedance is large. On the other hand, the areas that have been melted and solidified 37 or thermocompression bonded 38 do not have an air layer between them, so the ultrasonic waves pass through without being reflected.

[0017] The acquisition unit 15 acquires data of the echo waves 25 propagating in the overlapping direction of the plurality of plate-shaped materials 35. The acquisition unit 15 then acquires data of the echo waves 25 propagating in the overlapping direction of the plurality of plate-shaped materials 35 at any plurality of points P (P a ,P b ,P c . . . ) can be acquired. That is, the echo wave 25 reflects the state of the overlapping surface of the object under test 30 in the depth direction at the point P where the echo wave 25 is received.

[0018] The first detector 11 detects the first peaks 21 (211, 212, 213, ...) at the position corresponding to the bottom surface 36 of the object 30 from the echo wave 25. The first peaks 21 (211, 212, 213, ...) at the point P (P a ,P b ) echo waves 25 (25a, 25b) are repeatedly reflected between the top surface 34 and the bottom surface 36 of the object 30. Therefore, the first peaks 21 (211, 212, 213...) are detected at a time interval t1 corresponding to the distance (w1+w2-s1-s2) between the top surface 34 and the bottom surface 36. Here, w1 and w2 represent the thickness of the plate-shaped material 35 (351, 352), and s1 and s2 represent the depth of the dent made by the welding electrode.

[0019] The distance between the top surface 34 and the bottom surface 36 (w1+w2-s1-s2) and the time interval t1 between the first peaks 21 are expressed by the following equation as the propagation speed V of the ultrasonic wave in the object under test 30. Here, w1, w2, s1, s2, and V are known quantities that can be obtained by other measurement means, so the time interval t1 between the first peaks 21 can be calculated in advance. 2×(w1+w2-s1-s2)=V×t1

[0020] The first detector 11 detects the peaks of the echo wave 25 that exceed a set threshold (not shown) and are at a time interval t1 as first peaks 21 (211, 212, 213, ...). The points P (P a ,P b ) originates from the echo wave 25 from the bottom surface 36, so that a melt solidification 37 or a thermocompression bond 38 is formed in the depth direction.

[0021] 5, the time interval t3 of the third peaks 23 (231, 232, 233...) of the echo waves 25c from the contact surface 39 is different from the time interval t1 of the first peaks 21 (211, 212, 213...) of the echo waves 25a, 25b from the bottom surface 36. Therefore, it can be said that the echo waves 25 whose peaks are detected at times other than the time interval t1 are derived from reflections from the contact surface 39 or a welding defect (not shown).

[0022] The determination unit 17 determines whether the overlapping surfaces of the plate-shaped materials 35 (351, 352) are melted and solidified 37 or thermocompression bonded 38 based on the attenuation ratio of the intensities of the first peaks 21 (211, 212, 213...) of the echo waves 25. Here, in Fig. 3, the ridge line 26 connecting the first peaks 21 of the echo waves 25a that have passed through the melt and solidified 37 is shown by a dashed dotted line. In Fig. 4, the ridge line 27 connecting the first peaks 21 of the echo waves 25b that have passed through the thermocompression bond 38 is shown by a dashed two-dotted line.

[0023] Comparing the two ridgelines 26, 27, it can be seen that the attenuation ratio of the intensity of the first peak 21, which is repeatedly reflected, increases as the echo wave 25b passes through the thermocompression bond 38. The attenuation ratio of the intensity of the first peak 21 can be calculated based on a plurality of first peaks 21 (211, 212, 213...) or on two specified first peaks 21. The threshold value of the attenuation ratio for distinguishing between the melt solidification 37 and the thermocompression bond 38 can be experimentally determined in advance with reference to destructive test results, or by gradually moving the point P at which the echo wave 25 is acquired and searching for a discontinuous point in the change in the calculated attenuation ratio.

[0024] The display unit 18 displays information about the welding state in the depth direction at a specified point P on the surface 34 of the inspected object 30 where lap resistance welding has been performed. In other words, the display unit 18 allows the inspector to recognize whether the overlapping surfaces located in the depth direction of the specified point P are melted and solidified 37, thermocompression bonded 38, or in contact with each other 39.

[0025] (Second embodiment) Next, a second embodiment of the present invention will be described with reference to Fig. 6, Fig. 2, and Fig. 4. Fig. 6 is a configuration diagram of an ultrasonic inspection device 10B according to the second embodiment of the present invention. In Fig. 6, parts having the same configuration or function as those in Fig. 1 are designated by the same reference numerals, and duplicated explanations will be omitted.

[0026] In this way, the ultrasonic inspection device 10B is equipped with an acquisition unit 15 that acquires data of echo waves 25 (25a, 25b, 25c) from ultrasonic flaw detection, a first detection unit 11 that detects a first peak 21 (211, 212, 213...) from the echo wave 25 at a position corresponding to the bottom surface 36 of the object to be inspected 30, and a second detection unit 12 that detects the intensity of a second peak 22 (221, 222, 223...) from the echo wave 25 at a position corresponding to the overlapping surface, and a judgment unit 17 judges whether the overlapping surface of the plate-shaped material 35 (351, 352) is melted and solidified 37 or thermocompressed 38 based on the ratio of the intensity of the first peak 21 to the intensity of the second peak 22 of the echo wave 25.

[0027] The second detection unit 12 detects second peaks 22 (221, 222, 223...) from the echo wave 25 at positions corresponding to the thermocompression bonding 38 of the test object 30. That is, the second detection unit 12 detects second peaks 22 (221, 222, 223...) from the echo wave 25b at a time interval t2 from the first peak 21 (211, 212, 213...). a At this point, the echo wave 25a is not partially reflected on the way. a 3, the second peak 22 is not detected among the first peaks 21 (211, 212, 213, . . . ) which are repeated reflections between the top surface 34 and the bottom surface 36, and only a noise waveform is detected.

[0028] On the other hand, at point P where the thermocompression bond 38 is formed in the depth direction b At this point, the echo wave 25b is partially reflected. b4, a second peak 22 is detected superimposed on a noise waveform at a position corresponding to the thermocompression bond 38 between adjacent first peaks 21 (211, 212, 213 . . . ).

[0029] The determination unit 17 determines whether the overlapping surfaces of the plate-shaped materials 35 (351, 352) are melted and solidified 37 or thermocompression bonded 38 based on the ratio between the intensity of any one of the plurality of first peaks 21 and the intensity of any one of the plurality of second peaks 22. This is because the difference in intensity of the second peak 22 is small compared to the noise waveform, and it is difficult to set a threshold value for identifying the second peak 22 by itself. The first peak 21 and second peak 22 selected to calculate the intensity ratio are fixed in advance.

[0030] Comparing echo wave 25a (FIG. 3) that does not pass through thermocompression bond 38 with echo wave 25b (FIG. 4) that does pass through thermocompression bond 38, it can be seen that the intensity of second peak 22 formed at the corresponding position of echo wave 25b increases when echo wave 25b passes through thermocompression bond 38. The threshold value of the intensity ratio that distinguishes between melt solidification 37 and thermocompression bond 38 can be determined experimentally in advance with reference to destructive test results, or by gradually moving point P where echo wave 25 is acquired and searching for a discontinuous point in the change in the calculated intensity ratio.

[0031] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Fig. 7, Fig. 8(A) and (B), and Fig. 2 to Fig. 5. Fig. 7 is a configuration diagram of an ultrasonic inspection device 10C according to a third embodiment of the present invention. Fig. 8(A) is a cross-sectional view of an object under inspection 30 applied in the third embodiment. Fig. 8(B) is an inspection screen displaying the periphery of a contact surface 39 at a welded portion of the object under inspection 30. In Fig. 7, parts having the same configuration or function as those in Fig. 1 are designated by the same reference numerals, and duplicated explanations will be omitted.

[0032] As described above, the ultrasonic inspection device 10C includes an acquisition unit 15 that acquires data of the echo waves 25 (25a, 25b, 25c) of the ultrasonic flaw detection test, a first detection unit 11 that detects first peaks 21 (211, 212, 213...) from the echo waves 25 at positions corresponding to the bottom surface 36 of the object 30 to be inspected, and a determination unit 17 that determines whether the overlapping surfaces of the plate-shaped materials 35 (351, 352, 353) are melted and solidified 37 or thermocompression-bonded 38 (381, 382) based on the echo waves 25. Note that in the ultrasonic inspection device 10C of the third embodiment, as described in the second embodiment (FIG. 6), the second detection unit 12 may detect the intensity of the second peaks 22 (221, 222, 223...) and determine whether the overlapping surfaces are melted and solidified 37 or thermocompression-bonded 38.

[0033] The ultrasonic inspection device 10C further includes a third detection unit 13 that detects the third peak 23 (231, 232, 233...) of the echo wave 25c at the contact surface 39 (391, 392) of the overlapping surface of the plate-shaped material 35, an association unit 28 that associates the echo wave 25 corresponding to each of the multiple pixels that define an area 40 when the object 30 is viewed in a plane, and an image generation unit 29 that causes the pixel where the first peak 21 is detected to produce a first color 41 and the pixel where the third peak 23 is detected to produce a third color 43 (431, 432).

[0034] Here, as shown in Figure 8(A), when the test object 30 has three or more overlapping plate-shaped materials 35 (351, 352, 353), the pixels that emit the third color 43 (431, 432) are further color-coded according to the different contact surfaces 39 (391, 392).

[0035] The third detection unit 13 detects third peaks 23 (231, 232, 233...) of the echo waves 25c at contact surfaces 39 (391, 392) where an air layer is present among the overlapping surfaces of the plate-shaped materials 35. Note that if there are n overlapping plate-shaped materials 35, the number of contact surfaces 39 is n-1. Therefore, the number of time intervals t of the third peaks 23 required to identify which contact surface 39 it is is also n-1.

[0036] The associating unit 28 regards each of the plurality of pixels that partition the region 40 as the above-mentioned point P, and associates it with the corresponding echo wave 25. Therefore, the acquiring unit 15 acquires the echo wave 25 that corresponds to each of the plurality of pixels that partition the region 40.

[0037] The image generating unit 29 causes the pixel where the first peak 21 is detected to have a first color 41. As a result, as shown in FIG. 8(B), in a top view of the test object 30, the region of the overlapping surfaces where melted solidification 37 or thermocompression bonding 38 is formed is displayed in the first color 41. Then, by further analyzing the echo waves 25a of the pixels in the region displayed in the first color 41, it can be determined whether or not thermocompression bonding 38 has occurred.

[0038] Here, in a top view of the test object 30, the region of the overlapping surface where the contact surface 391 is formed with the plate-shaped material 351 having the surface 34 is displayed in a third color 432. Furthermore, the region of the overlapping surface where the thermocompression bond 381 or melt-solidification 37 is formed with the plate-shaped material 351 having the surface 34 and the contact surface 392 is formed with the second layer of plate-shaped material 352 is displayed in a third color 431. Then, by further analyzing the echo waves 25a, 25b of the pixels in the region displayed in the first color 41 and the third color 431, it can be determined whether or not there is a thermocompression bond 38 (381, 382).

[0039] FIG. 8(C) is an inspection screen further displaying the periphery of the thermocompression bonded portion 38 (381, 382). In this way, the image generating unit 29 can cause the pixels where the thermocompression bonded portion 38 (381, 382) has been formed to produce a second color 42 (421, 422). The display unit 18 then displays information about the welding state in the depth direction of the constituent pixels of region 40 when the inspected object 30 where lap resistance welding has been performed is viewed from above. In other words, the welded portion region 40 can be viewed from above to display planar information about whether the welded portion has melted and solidified 37, thermocompressed 38, or formed a contact surface 39, allowing the inspector to recognize this.

[0040] 9 is a flowchart of an ultrasonic inspection method and an ultrasonic inspection program according to each embodiment (see FIG. 8 as needed). First, data of echo waves 25 (25a, 25b, 25c) of an ultrasonic flaw detection inspection of a lap resistance welded object 30, which is made up of a plurality of overlapping plate-shaped materials 35 (351, 352, 353), is acquired (S11). Then, from these echo waves 25, a first peak 21 (211, 212, 213...) (FIGS. 3 and 4) at a position corresponding to the bottom surface 36 of the object 30 is detected (S12; Yes). Of the plurality of pixels defining an area 40 in a planar view of the object 30, a pixel associated with the determined echo wave 25 is colored in a first color 41 (S13).

[0041] Furthermore, based on this echo wave 25, it is determined whether the overlapping surfaces of the plate-shaped materials 35 (351, 352, 353) are melted and solidified 37 or thermocompression bonded 38 (S16). If it is determined that the overlapping surfaces are thermocompression bonded 38, the pixel is caused to exhibit a second color 42 (S17). This determination is made based on the attenuation ratio of the intensity of the first peaks 21 (211, 212, 213...) of the echo wave 25 and the intensity of the second peaks 22 (221, 222, 223...) at positions corresponding to the overlapping surfaces of the plate-shaped materials 35 (351, 352, 353).

[0042] Then, if the first peaks 21 (211, 212, 213...) are not detected (S12; No), the third peaks 23 (231, 232, 233...) of the echo waves 25c at the contact surfaces 39 (391, 392) are detected (S14). Note that if there are three or more overlapping plate-like materials 35 and there are multiple contact surfaces 39, it is determined from which contact surface 39 the echo waves 25c correspond to the third peaks 23, based on the time interval t of the third peaks 23.

[0043] Then, the pixel associated with the determined echo wave 25 is caused to develop a third color 43 (431, 432) (S15). Furthermore, based on this echo wave 25, it is determined whether the overlapping surfaces of the plate-shaped materials 35 (351, 352, 353) are melted and solidified 37 or thermocompression bonded 38 (S16). Then, if it is determined to be thermocompression bonded 38, the pixel is caused to develop a second color 42 (S17).

[0044] Next, the above-mentioned processes (S11) to (S17) are repeated for the echo wave 25 associated with another pixel, and data processing is performed for all pixels that partition the region 40 (S18; Yes, No).

[0045] According to at least one of the embodiments of the ultrasonic inspection device described above, it is possible to determine with high reliability the soundness of the welding condition of the lap resistance welded joint by determining whether the overlapping surfaces of the plate-shaped materials constituting the object to be inspected are melted and solidified or thermocompression bonded.

[0046] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as the inventions described in the claims and their equivalents.

[0047] The ultrasonic inspection device described above includes a control device with a highly integrated processor such as a dedicated chip, FPGA (Field Programmable Gate Array), GPU (Graphics Processing Unit), or CPU (Central Processing Unit), a storage device such as ROM (Read Only Memory) or RAM (Random Access Memory), an external storage device such as HDD (Hard Disk Drive) or SSD (Solid State Drive), a display device such as a monitor, input devices such as a mouse and keyboard, and a communication I / F, and can be realized as a hardware configuration using a normal computer equipped with a processor. Furthermore, this ultrasonic inspection device can also be configured by combining separate modules that independently perform the functions of the components and are connected to each other via a network or dedicated lines.

[0048] The data processing program may be provided by being pre-installed in a ROM or the like. Alternatively, the program may be provided by being stored in an installable or executable file format on a computer-readable storage medium such as a CD-ROM, CD-R, memory card, DVD, or flexible disk (FD). Furthermore, the program may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. [Explanation of symbols]

[0049] 10 (10A, 10B, 10C)...ultrasonic inspection device, 11...first detection unit, 12...second detection unit, 13...third detection unit, 15...acquisition unit, 17...determination unit, 18...display unit, 21...first peak, 22...second peak, 23...third peak, 25 (25a, 25b, 25c)...echo wave, 26...first ridge line, 27...second ridge line, 28...association unit, 29...image generation unit, 30...object to be inspected, 34...surface, 35...plate-shaped material, 36...bottom surface, 37...melting and solidifying, 38...thermocompression bonding, 39...contact surface, 40...area, 41...first color generation, 42...second color generation, 43...third color generation.

Claims

1. an acquisition unit that acquires data of echo waves from an ultrasonic flaw detection test in lap resistance welding of an object to be inspected in which a plurality of plate-shaped materials are overlapped; a first detector that detects a first peak from the echo wave at a position corresponding to the bottom surface of the object; a determination unit that determines whether the overlapping surfaces of the plate-shaped materials are melted and solidified or thermocompression bonded based on the echo waves; a third detector for detecting a third peak of the echo wave at a contact surface of the overlapping surfaces of the plate-shaped materials; an associating unit that associates the echo waves corresponding to each of a plurality of pixels that partition an area of ​​the object to be inspected in a plan view; an image generating unit that causes the pixel in which the first peak is detected to emit a first color and the pixel in which the third peak is detected to emit a third color, An ultrasonic inspection device in which, when the object to be inspected has three or more overlapping plate-shaped materials, the pixels that emit the third color are further color-coded according to the different contact surfaces.

2. 2. The ultrasonic inspection device according to claim 1, a second detector that detects a second peak from the echo wave at a position corresponding to the overlapping surface; The determination unit performs the determination based on the ratio of the intensities of the first peak and the second peak.

3. 2. The ultrasonic inspection device according to claim 1, The image generating unit causes the pixel where the thermocompression bonding is detected to emit a second color.

4. A step of acquiring data of echo waves from an ultrasonic flaw detection test in lap resistance welding of an object to be inspected in which a plurality of plate-shaped materials are overlapped; detecting a first peak from the echo wave at a position corresponding to the bottom surface of the object; a step of determining whether the overlapping surfaces of the plate-shaped materials are melted and solidified or thermocompression bonded based on the echo waves; detecting a third peak of the echo wave at a contact surface of the overlapping surfaces of the plate-shaped materials; a step of associating the echo waves corresponding to each of a plurality of pixels that partition an area of ​​the object to be inspected in a plan view; causing the pixel where the first peak is detected to emit a first color, and causing the pixel where the third peak is detected to emit a third color, In the step of causing the pixels to emit a third color, if the object to be inspected has three or more overlapping plate-shaped materials, the pixels that emit the third color are further color-coded according to the different contact surfaces.

5. On the computer, A step of acquiring data of echo waves from an ultrasonic flaw detection test in lap resistance welding of an object to be inspected in which a plurality of plate-shaped materials are overlapped; detecting a first peak from the echo wave at a position corresponding to the bottom surface of the object; a step of determining whether the overlapping surfaces of the plate-shaped materials are melted and solidified or thermocompression-bonded based on the echo waves; detecting a third peak of the echo wave at a contact surface of the overlapping surfaces of the plate-shaped materials; a step of associating the echo waves corresponding to each of a plurality of pixels that partition an area of ​​the object to be inspected in a plan view; causing the pixel where the first peak is detected to emit a first color, and causing the pixel where the third peak is detected to emit a third color; An ultrasonic inspection program in which, in the step of causing the pixels to emit a third color, if there are three or more plate-shaped materials stacked on top of each other in the test object, the pixels that emit the third color are further color-coded according to each of the different contact surfaces.

Images