Welding quality judgment device for arc welding, welding quality judgment method for arc welding, and welding quality judgment program for arc welding

Abstract

To provide a welding quality determination device for determining the welding quality by estimating a penetration amount of a metal member generated in a weld zone of arc-welding by a non-destructive inspection.SOLUTION: A welding quality determination device comprises: an irradiation unit which emits an electromagnetic wave in a prescribed wavelength to a weld zone and the vicinity of the weld zone; a detection unit which detects the reflection wavelength reflected by emitting the electromagnetic wave; and a processing unit which generates a reflection spectrum of the reflection wavelength. The processing unit comprises: a welding state acquisition part which acquires the welding state by detecting the reflection wavelength reflected from the weld zone and the vicinity of the weld zone after arc-welding; a selection part which previously holds the combination of the wavelength of the emitted electromagnetic wave and the welding state after arc-welding and selects the wavelength of the electromagnetic wave emitted from the irradiation unit on the basis of the welding state; an irradiation instruction part which generates an instruction of emitting the selected wavelength; a distribution generation part which generates the spectral distribution by acquiring the reflection spectrum; a determination part which determines the welding quality on the basis of the spectral distribution; and an output part which outputs the result of determination of the welding quality.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a welding quality judgment device for arc welding, a welding quality judgment method for arc welding, and a welding quality judgment program for arc welding, and relates to a welding quality judgment device, method, and program for judging the welding quality of arc-welded workpieces using a non-destructive optical technique. [Background technology]

[0002] Arc welding is used to join metal components such as steel plates together by welding. After arc welding, it is confirmed that the welded parts of the metal components meet the specified welding conditions. Specifically, there are non-destructive inspection methods, such as a method of irradiating the welded part with ultrasonic waves after arc welding to inspect the inside of the welded part, and a method of irradiating the welded part with radiation (X-rays) to inspect the inside of the welded part after arc welding. In addition, the welded part after arc welding is cut, polished, treated with a solvent, etc., and then observed under a microscope.

[0003] The aforementioned ultrasonic inspection is only effective in detecting the presence or absence of bubbles (voids) known as blowholes that occur in welded areas. Inspection of radiation exposure requires bringing a radiation source and detector to the site. This makes it difficult to inspect the welded areas of large or complex-shaped parts, and it is also not possible to estimate the penetration of metal materials during arc welding.

[0004] When cutting the welded area for inspection, it is a destructive inspection and can only be performed by sampling, which requires a lot of man-hours for processing. In addition, the inspection burden increases as the number of arc welding points (total number of welds) increases.

[0005] Given these circumstances, there has been a demand for non-destructive testing methods to replace ultrasonic testing and radiographic testing.Specific examples that have been proposed include a method of inspecting welding quality by irradiating a welded portion of an arc weld with slit light and obtaining a light-section image using the reflected light (see Patent Document 1), a welding observation device that uses an RGB bandpass filter in a telecentric optical system (see Patent Document 2), and an arc welding monitoring device that is equipped with a bandpass filter in the infrared wavelength region and a bandpass filter in the ultraviolet wavelength region (see Patent Document 3). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 6-94640 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-70002 [Patent Document 3] Japanese Patent Application Laid-Open No. 2009-125790 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the inspection accuracy obtained by the previously proposed non-destructive inspection methods and devices for arc welding was not necessarily sufficient for inspecting the melted portion of the arc weld. In particular, the accuracy of the existing methods and devices was not sufficient for estimating the penetration amount of metal members during arc welding.

[0008] The present invention has been made in consideration of the above points, and provides an arc welding welding quality judgment device, an arc welding welding quality judgment method, and an arc welding welding quality judgment program that enable judgment of welding quality by estimating the amount of penetration of metal members that occurs in a welded portion of an arc weld in non-destructive testing using electromagnetic waves of a predetermined wavelength. [Means for solving the problem]

[0009] That is, an embodiment is a welding quality judgment device for an arc welded welded portion produced by arc welding a first member and a second member, and the welding quality judgment device includes an irradiation unit that irradiates the welded portion and the vicinity of the welded portion with electromagnetic waves of a predetermined wavelength, a detection unit that irradiates the electromagnetic waves and detects reflected wavelengths reflected from the welded portion and the vicinity of the welded portion, and a processing unit that generates a reflection spectrum of the reflected wavelengths detected by the detection unit, and the processing unit detects the reflected wavelengths reflected from the welded portion and the vicinity of the welded portion after arc welding through the detection unit, and acquires the welding state of the welded portion and the vicinity of the welded portion; The present invention is characterized in that it comprises a selection unit that stores in advance a combination of a welding state that occurs in the welded portion and the vicinity of the welded portion after arc welding and a wavelength of an electromagnetic wave to be irradiated to the welded portion and the vicinity of the welded portion, and selects a wavelength of the electromagnetic wave to be irradiated from the irradiation unit based on the acquired welding state; an irradiation instruction unit that generates an instruction to irradiate the electromagnetic wave of the selected wavelength from the irradiation unit; a distribution generation unit that acquires the reflection spectrum of the welded portion and the vicinity of the welded portion after arc welding and generates a spectral distribution; and a determination unit that determines the welding quality based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding.

[0010] Furthermore, the judgment unit of the processing unit may be configured to estimate the amount of penetration that has occurred in the first member and the second member based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding, and judge the welding quality.

[0011] Furthermore, the judgment unit of the processing unit may judge the welding quality based on a correspondence table that associates the combination of the first and second members with the arc welding conditions for the first and second members and shows the association between the spectral distribution and the penetration amount.

[0012] Furthermore, the first member and the second member may be made of the same type of metallic material.

[0013] Furthermore, the electromagnetic waves of the predetermined wavelength may be a plurality of electromagnetic waves with different wavelengths, or may be two types of electromagnetic waves: electromagnetic waves in the blue to ultraviolet wavelength band and electromagnetic waves in the near-infrared wavelength band.

[0014] Furthermore, the detection unit of the welding quality assessment device may include an imaging unit that captures an image of the welded portion and the vicinity of the welded portion formed by the first member and the second member after arc welding, the processing unit may include an image acquisition unit that acquires an image of the welded portion after arc welding captured by the imaging unit, and the distribution generation unit may overlay an image of the spectral distribution on the image of the welded portion.

[0015] Furthermore, the processing unit may include an output unit that outputs the result of the judgment of the welding quality. [Effects of the Invention]

[0016] The weld quality judgment device for arc welding of the present invention is a weld quality judgment device for an arc weld of a weld formed by arc welding a first member and a second member, and the weld quality judgment device includes an irradiation unit that irradiates the weld and the vicinity of the weld with electromagnetic waves of a predetermined wavelength, a detection unit that irradiates the electromagnetic waves and detects reflected wavelengths reflected from the weld and the vicinity of the weld, and a processing unit that generates a reflection spectrum of the reflected wavelengths detected by the detection unit, and the processing unit detects the reflected wavelengths reflected from the weld and the vicinity of the weld after arc welding via the detection unit to acquire the welding condition of the weld and the vicinity of the weld, and and a determination unit that determines welding quality based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding. The non-destructive testing system includes: a selection unit that stores in advance a combination of the welding state and the wavelength of the electromagnetic waves to be irradiated from the irradiation unit based on the acquired welding state; an irradiation instruction unit that generates an instruction to irradiate electromagnetic waves of the selected wavelength from the irradiation unit; a distribution generation unit that acquires the reflection spectrum of the welded portion and the vicinity of the welded portion after arc welding and generates a spectral distribution; and a determination unit that determines welding quality based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding. Therefore, in non-destructive testing using electromagnetic waves, it is possible to estimate the amount of penetration of metal members that occurs in the welded portion by arc welding and determine welding quality. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram illustrating a welding quality determination device for arc welding according to an embodiment; [Figure 2] FIG. 1A is a cross-sectional schematic view showing the state after arc welding, and FIG. 1B is a plan schematic view showing the state after arc welding. [Figure 3] (A) Schematic cross-sectional view after arc welding with a large amount of penetration, (B) Schematic plan view after arc welding with a large amount of penetration, (C) Schematic cross-sectional view after arc welding with a small amount of penetration, (D) Schematic plan view after arc welding with a small amount of penetration. [Figure 4] 2 is a block diagram showing the functional parts of the welding quality determination device; FIG. [Figure 5] (A) Estimated force diagram mapping the width and wavelength of oxidation occurring at and near the weld, and (B) is a schematic diagram of the correlation. [Figure 6] FIG. 10 is a diagram showing the length of the welded state with each width. [Figure 7] FIG. 1 is a schematic diagram showing the correlation between wavelength, location, and the quality of the welding state. [Figure 8] FIG. 10 is a schematic diagram of an estimated force diagram showing the correlation between each wavelength of the irradiated electromagnetic wave and the width region after arc welding. [Figure 9] FIG. 2 is a schematic diagram showing a cross section and spectral reflectance at a welded portion. [Figure 10] (A) Cross-sectional photograph of a welded area with no penetration, (B) Planar photograph of a welded area with no penetration, (C) Spectroscopic image of a planar welded area with no penetration. [Figure 11] (A) Cross-sectional photograph of a welded area with low penetration, (B) Planar photograph of a welded area with low penetration, (C) Spectroscopic image of a planar welded area with low penetration. [Figure 12] (A) Cross-sectional photograph of a welded area with a large amount of penetration, (B) Planar photograph of a welded area with a large amount of penetration, (C) Spectroscopic image of a planar welded area with a large amount of penetration. [Figure 13] 10A and 10B are planar photographs of a welded area when irradiated with electromagnetic waves of different wavelengths. [Figure 14] FIG. 2 is a schematic diagram showing spectral reflectance when irradiated with electromagnetic waves of different wavelengths. [Figure 15]3 is a flowchart illustrating a method for determining welding quality of arc welding according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of a welding quality assessment device 1 for arc welding will be described using the schematic diagram of FIG. 1. The welding quality assessment device 1 is a device that assesses the quality of a weld 20 formed by arc welding a first member W1 and a second member W2 of metal members such as steel plates or steel materials. The welding quality assessment device 1 is a device that assesses the amount of metal penetration that occurs between the first member W1 and the second member W2 during arc welding, and the thickness of the members (the so-called welding state), through non-destructive testing based on an optical technique of spectral distribution using electromagnetic waves (wavelength band from infrared light to ultraviolet light). The illustration shows only one example of the device. The arrangement and orientation of each member and device may be as appropriate.

[0019] In the figure, the first member W1 and the second member W2 are both steel plates (galvanized steel plates), with the first member W1 serving as the base material and the second member W2 stacked on top of it. Linear arc welding is then performed on the end of the second member W2, resulting in a weld 20 at the end of the second member W2. The area of ​​the weld 20 on the first member W1 side and the area on the second member W2 side are called the weld vicinity 21.

[0020] The welding quality judgment device 1 includes an irradiation unit 2, a detection unit 3, an imaging unit 4, and a processing unit 10. The irradiation unit 2, the detection unit 3, and the imaging unit 4 are connected to the processing unit 10 (computer) by wire or wirelessly. As shown in the figure, the irradiation unit 2, the detection unit 3, and the imaging unit 4 are provided on the side facing the welded portion 20 and the vicinity of the welded portion 21.

[0021] Irradiation unit 2 is a light source that selects electromagnetic waves of a predetermined wavelength, mainly electromagnetic waves in a wavelength band ranging from infrared light (800 nm) to ultraviolet light (200 nm), and irradiates welded portion 20 and the vicinity of welded portion 21. For example, a halogen lamp or the like is used. If necessary, irradiation unit 2 may also be equipped with an optical filter (bandpass filter) or the like for selecting the irradiation wavelength.

[0022] The detection unit 3 detects the reflected wavelength that occurs when electromagnetic waves of a predetermined wavelength irradiated from the irradiation unit 2 are reflected by the welded portion 20 and the vicinity of the welded portion 21. The irradiation unit 2 irradiates electromagnetic waves of a specific wavelength. However, arc welding causes changes in the surface roughness and material of the welded portion 20 and the vicinity of the welded portion 21, and the reflected wavelength changes from the irradiated wavelength. The electromagnetic waves (light) of the original irradiated wavelength are not reflected as is, but are reduced from the original irradiated wavelength by the welded portion 20 and the vicinity of the welded portion 21.

[0023] The detection unit 3 can sensitively detect reflected wavelengths, thereby detecting the relative amount of electromagnetic waves (light) reflected from any part of the welded part 20 and the vicinity of the welded part 21. The detection unit 3 uses equipment such as a multispectral camera or a hyperspectral camera.

[0024] The photographing unit 4 is a device that optically photographs the weld 20 formed by the first member W1 and the second member W2 and the vicinity of the weld 21. Specifically, it is a known CCD camera, a camera equipped with a CMOS image sensor, or the like.

[0025] The processing unit 10 is any of various electronic computers (computing resources), such as a personal computer (PC), a mainframe, a workstation, a cloud computing system, etc. The illustrated processing unit 10 is a personal computer, to which a display 16 for displaying the determination results, and other input devices such as a keyboard 17 and a mouse 18 are connected.

[0026] FIG. 2 is a schematic diagram of a weld 20 and the vicinity 21 of the weld formed by the first member W1 and the second member W2. FIG. 2(A) is a schematic cross-sectional view showing the state after arc welding. As heat is generated during arc welding, the first member W1, the second member W2, and the wire melt at the end 22, joining the first member W1 to the second member W2. Then, a welded portion 24 is formed at the end 22 together with a buildup portion 23. The more welded portions 24 there are, the greater the amount of fusion between the first member W1 and the second member W2, resulting in a better weld condition.

[0027] 2(B) is a schematic plan view showing the state after arc welding, in which a second member W2 is placed on a first member W1, both of which are steel plates, and arc welding is performed on an end 22 of the second member W2. In arc welding, an electrode wire (not shown) is supplied and generates heat, causing the first member W1 and the second member W2 and the wire to melt at the end 22, joining the first member W1 and the second member W2. Furthermore, if the gas supplied during arc welding contains carbon dioxide, the metal surfaces of the first member W1 and the second member W2 are oxidized, and an oxide film 25 is formed in the vicinity 21 of the weld.

[0028] Generally, the condition of an arc welded joint cannot be ascertained unless it is cut as shown in the cross-sectional schematic diagram of Fig. 2(A). In contrast, the weld quality assessment device 1 estimates the size of the internal penetration area 24 from non-destructive observation of the welded joint 20 and the vicinity of the welded joint 21 as shown in the plan schematic diagram of Fig. 2(B), making it possible to assess the quality of the weld. The arrow z in Fig. 2 indicates the scanning direction, which will be described later. For convenience, the shaded areas in Fig. 2(B) indicate areas discolored by arc welding.

[0029] The schematic diagrams in Figure 3 compare the amount of penetration after arc welding. Figure 3(A) is a cross-sectional schematic diagram after arc welding when the amount of penetration is large. In this case, as shown in the plan view schematic diagram in Figure 3(B), patterns corresponding to the internal structure of the weld 20 and the vicinity of the weld 21 (see the patterns in the photographs in Figures 6, 7, and 8) appear on the surface of the weld 20 and the vicinity of the weld 21.

[0030] In contrast, Fig. 3(C) is a cross-sectional schematic diagram after arc welding when the amount of penetration is small. In this case, as shown in the plan view schematic diagram of Fig. 3(D), the patterns corresponding to the internal structure of the weld 20 and the vicinity of the weld 21 are spaced closer together than in Fig. 3(B) above. The amount of penetration, surface appearance, thickness of the molten metal (base metal penetration, base metal leg length, joint penetration, joint leg length, etc.), throat thickness, etc. of the weld 20 and the vicinity of the weld 21 after arc welding shown in Figs. 3(A) to 3(D) represent the welding condition.

[0031] Normally, in optical observation using visible light, it is difficult to distinguish sharply the difference in the spacing between the patterns in Figures 3(B) and 3(D). Therefore, the weld quality judgment device 1 irradiates electromagnetic waves (light) of a predetermined wavelength and sharply distinguishes the difference in the spacing between the patterns from the spectral distribution of the reflected waves, making it possible to estimate the differences in components and structure.

[0032] 4 is a block diagram showing the configuration and functional units of the processing unit 10. The processing unit 10 is equipped with a CPU 11 for executing various calculations, a ROM 12 for storing processing programs, a RAM 13 for storing data, etc., a memory unit 14 for storing various data and calculation results, etc., and an I / O (input-output interface) 15, etc. The I / O 15 is an interface, buffer, etc. for communication (transmission and reception). The I / O 15 is used to send irradiation control signals to the irradiation unit 2 and receive input signals from the detection unit 3, the imaging unit 4, etc., and works in conjunction with the CPU 11.

[0033] 4 shows functional units within CPU 11. When each functional unit of CPU 15 is realized by software, CPU 15 realizes the unit by executing instructions of a program, which is software that realizes each function. In detail, CPU 15 includes welding state acquisition unit 110, selection unit 120, irradiation instruction unit 130, distribution generation unit 140, image acquisition unit 150, determination unit 160, output unit 170, etc.

[0034] The welding condition acquisition unit 110 detects the reflected wavelengths reflected from the welded portion 20 and the vicinity 21 of the first member W1 and the second member W2 after arc welding via the detection unit 3, and acquires the welding condition of the welded portion 20 and the vicinity 21 of the welded portion. As described above, the welding condition indicates the penetration amount, surface appearance, and thickness of the molten metal of the welded portion 20 and the vicinity 21 of the welded portion after arc welding. In surface inspection of the welded portion 20 and the vicinity 21 of the welded portion shown in FIGS. 2 and 3, the welding condition, such as the penetration amount, the spread of the pattern, the thickness of the molten metal (base metal penetration, base metal leg length, joint penetration, joint leg length, etc.), throat thickness, and the degree of metal oxidation, varies depending on the object being inspected. Therefore, it is necessary to acquire the welding condition of the first member W1 and the second member W2 to be welded after arc welding in advance. In addition to acquiring the welding condition via the detection unit 3, the metal materials of the first member W1 and the second member W2 to be welded may be input. In addition to being input directly to the processing unit 10, the data may be taken into the processing unit 10 from design data such as CAD data.

[0035] The selection unit 120 stores in advance a combination of the welding state occurring at the welded portion 20 and the vicinity of the welded portion 21 after arc welding and the wavelength of the electromagnetic wave to be irradiated to the welded portion 20 and the vicinity of the welded portion 21. Then, the selection unit 120 selects the wavelength of the electromagnetic wave to be irradiated from the irradiation unit 2 based on the acquired welding state.

[0036] As mentioned above, the welding conditions when arc welding is performed on the first member W1 and the second member W2 to be welded are different. Therefore, the spectral distribution of the reflected wave differs depending on the wavelength of the electromagnetic wave (light) irradiated. For this reason, it is extremely important to select a wavelength that will allow for an efficient spectral distribution to be obtained according to the inspection of each welding condition.

[0037] In one embodiment, electromagnetic waves in a wavelength range from infrared light (approximately 1000 nm) to ultraviolet light (approximately 200 nm) are irradiated onto the surface of the welded portion of a test piece (sample) after arc welding in advance. The spectral distribution of the reflected waves is then obtained (see FIG. 5 ), and the welded portion of the test piece (sample) is cut and the cross section is observed. Based on the correlation between the welded state of the test piece (sample) and the pre-observation of the cut surface and the irradiated wavelength, an appropriate wavelength band of electromagnetic waves is selected for each welding state. Note that the selection of electromagnetic waves is not limited to a single specific wavelength, and multiple electromagnetic waves (light) with different wavelengths may be used. For example, it is convenient to use different wavelengths for determining the penetration amount, the oxide film, the base metal penetration, and the throat thickness.

[0038] The following describes further the welding conditions that occur at the weld 20 and the vicinity 21 of the weld when arc welding is performed on the first and second members W1 and W2 to be welded, and the wavelengths of the electromagnetic waves irradiated from the irradiation unit 2 corresponding to the welding conditions. Multiple test pieces (samples) with various conditions, such as good and bad, are prepared, and the test pieces (samples) are irradiated with electromagnetic waves in a wavelength range from infrared light (approximately 1000 nm) to ultraviolet light (approximately 200 nm). Oxidation occurs around the weld bead (reference numeral 20 in Figure 2(B)) due to the influence of welding heat, and the size of this range is presumed to correlate with the amount of penetration. Therefore, five widths (a-e) based on the maximum and minimum values ​​of reflectance are extracted (see Figure 5(A)).

[0039] For each of the five widths, a correlation diagram is extracted with the vertical axis representing each welding condition (base metal penetration, base metal leg length, joint penetration, joint leg length, etc.), throat thickness, etc.) and the horizontal axis representing wavelength. As an example, the correlation diagram between base metal penetration and wavelength is shown below. Correlation coefficients are calculated from the correlation diagram between each welding condition (base metal penetration, base metal leg length, joint penetration, joint leg length, etc.), throat thickness, etc.) and wavelength. Then, to quantitatively analyze the correlation between the wavelength of the irradiated electromagnetic waves (light) and the oxidation width occurring in the weld 20 and the vicinity of the weld 21, a correlation coefficient is calculated for each of the five widths (a-e) for each of the welding conditions (base metal penetration, base metal leg length, joint penetration, joint leg length, etc.), throat thickness, etc.), and an estimated force diagram (planar photograph and schematic diagram in FIG. 5(A)) is created, mapping the correlation coefficients with the oxidation width (five widths (a-e)) on the horizontal axis and the wavelength on the vertical axis. (See the schematic diagram in Figure 5(B)).

[0040] The example in Figure 6 shows the results of trials where irradiation was performed with varying wavelengths, primarily in the ultraviolet region. Similar trials were also performed in the visible and infrared regions. In Figure 6, five ranges (a to e) were detected, starting from the maximum and minimum values ​​of reflectance.

[0041] FIG. 7 is a schematic diagram showing the correlation between the detection results from each irradiation and the quality of the weld when a specific wavelength is irradiated multiple times for the five widths (a to e) in FIG. 6 . Specifically, this is a method for calculating the correlation coefficient shown in FIG. 5(B). In the example shown in FIG. 7, for example, electromagnetic waves (light) with a wavelength of 650 nm are irradiated (condition 1), and the surface of the region with width "a" is observed. Then, the actual cut surfaces of the region are observed. Approximately 30 cut surfaces (N1 to N30) are observed for roughly one condition. Then, the correlation coefficient is calculated for the distribution of the sample cut surfaces (N1 to N30) distributed on the horizontal axis of the 650 nm wavelength region "a" and the horizontal axis of the base metal penetration. Next, the same calculation is performed for the horizontal axis of the 650 nm wavelength region "b," and the correlation coefficient is calculated for all widths (a to e). Then, the correlation coefficients are calculated in the same way for the other wavelengths from 350 to 1100 nm in order. The magnitude of these correlation coefficient values ​​is reflected in the above-mentioned Figure 5(B).

[0042] The estimated force diagram in Fig. 8 is a table of Fig. 5(B), and shows the correlation between each wavelength of the irradiated electromagnetic wave (light) and five regions of width (a to e) in the welded part 20 and the vicinity of the welded part 21 after arc welding. In each square, the lighter the color, the higher the correlation, and the darker and blacker the correlation.

[0043] The estimated force diagram in Figure 8 shows the results for each welding condition, from left to right: base metal penetration, base metal leg length, joint penetration, joint leg length, and throat thickness. For each welding condition, the spectral distribution of reflection from each of the five widths (a to e) mentioned above is color-coded to indicate the correlation between the quality of the cut surface when actually cut. In this case, when the wavelength that provided a generally good correlation for each welding condition of base metal penetration, base metal leg length, joint penetration, joint leg length, and throat thickness was extracted, 425 nm was found to be appropriate.

[0044] The selection unit 120 previously stores a table (not shown) that associates welding states with the wavelengths of the electromagnetic waves to be irradiated that correspond to the welding states.

[0045] The irradiation instruction unit 130 generates an instruction to irradiate electromagnetic waves of the selected wavelength from the irradiation unit 2. The irradiation instruction unit 130 generates a control signal so that electromagnetic waves of the irradiation wavelength selected by the selection unit 120 can be irradiated from the irradiation unit 2. Alternatively, the irradiation instruction unit 130 generates a signal to select a filter for the light source.

[0046] The distribution generating unit 140 acquires the reflection spectrum of the welded portion 20 and the vicinity of the welded portion 21 after arc welding to generate a spectral distribution. Electromagnetic waves of a predetermined wavelength are irradiated onto the welded portion 20 and the vicinity of the welded portion 21 after arc welding, and the reflection spectrum is acquired. A spectral distribution is generated from this reflection spectrum. The electromagnetic waves of the predetermined wavelength reflected and detected from the welded portion 20 and the vicinity of the welded portion 21 are attenuated compared to the electromagnetic waves of the predetermined wavelength that are irradiated. Furthermore, the degree of attenuation varies from location to location. In other words, the change in the reflected spectrum appears as a spectral distribution. This makes it possible to calculate the amount of attenuation of the electromagnetic waves of the predetermined wavelength that are reflected and detected as a spectral reflectance.

[0047] Image acquisition unit 150 acquires an image of the welded portion after arc welding captured by imaging unit 4. The welded portion image is an image captured in the visible light range. By acquiring the welded portion image, distribution generation unit 140 can overlay an image of the spectral distribution on the welded portion image. This allows the user of welding quality assessment device 1 to comprehensively recognize the actual welded portion image and information on the spectral distribution.

[0048] The determination unit 160 determines the welding quality based on the spectral distribution along the scanning direction (see arrow z in FIG. 2) of the welded portion 20 and the vicinity of the welded portion 21 after arc welding. Furthermore, the determination unit can estimate the penetration portion 24 (see FIGS. 2 and 3) formed in the first member W1 and the second member W2 based on the spectral distribution along the scanning direction of the welded portion 20 and the vicinity of the welded portion 21 after arc welding, and determine the welding quality. The welding quality determined by the determination unit 160 is stored in the memory unit 14 of the processing unit 10, and the determined welding quality is also used as information for appropriate welding management.

[0049] The output unit 170 then outputs the results of the welding quality judgment. The output is displayed on the display 16 in FIG. 1. Because the output unit 170 outputs the results of the welding quality judgment, it is easy to understand the results of the judgment one after another. The scanning direction is the direction perpendicular to the linear weld 20 formed in a plan view of the first member W1 and the second member W2 after arc welding (see arrow z in FIG. 2). The welding quality is the quality of the arc welding based on the penetration portion formed in the first member W1 and the second member W2. As explained above in FIG. 3, the greater the penetration amount of the penetration portion, the better the welding quality of the arc welding is judged to be.

[0050] Figure 9 is a schematic diagram showing a cross-section and spectral reflectance of a welded portion. Electromagnetic waves of a predetermined wavelength are irradiated onto a weld 20 and the vicinity 21 of the weld, made of the metallic materials of the first member W1 and the second member W2 to be welded, and the resulting reflection spectrum is obtained. From this, the spectral reflectance can be calculated. The vertical axis of the graph in the lower part of the figure represents the spectral reflectance, and the horizontal axis represents the length (mm) corresponding to the cross section. Large drops in the graph correspond to areas with low spectral reflectance. The waveform of the graph corresponds to the position and size of the internal penetration 24 (see Figures 2 and 3). In other words, the greater the amount of penetration, the lower the spectral reflectance. From this, it is possible to estimate the position and size of the penetration from the waveform of the spectral reflectance.

[0051] When estimating the spectral reflectance waveform and the position and size of the penetration, a correspondence table is used in which the combination of the first member W1 and the second member W2 corresponds to the arc welding conditions for the first member W1 and the second member W2, and the spectral distribution and penetration amount are associated. That is, for each of the welding conditions described above, a predetermined relationship is found between the spectral reflectance value calculated based on the spectral distribution and the actual measured value of the penetration amount (penetration amount) of the test piece cut by arc welding. Therefore, the correspondence table, which shows the welding condition, the wavelength selected for irradiation, the spectral reflectance value, and the expected penetration amount (size and depth of the penetration area) like a quick reference, is created in advance and stored in the memory unit 14 of the processing unit 10. The correspondence table indirectly estimates the penetration amount of the penetration area, ultimately enabling the welding quality of the arc welding to be determined.

[0052] Figures 10, 11, and 12 show the state when the inventor arc-welded the metal materials (galvanized steel sheets) of the first and second members. Figure 10 shows the state when there is no penetration, Figure 11 shows the state when there is a small amount of penetration, and Figure 12 shows the state when there is a large amount of penetration. Each figure (A) is a cross-sectional photograph of the welded area, each figure (B) is a planar photograph of the welded area, and each figure (C) is a spectroscopic image of the planar surface of the welded area.

[0053] In the state of no penetration shown in Figure 9, the penetration area in Figure 10(A) (see reference numeral 24 in Figures 2 and 3) is barely visible, and the spacing between the surface patterns is narrower than in the photograph in Figure 10(B). Furthermore, the spectral image in Figure 10(C) is also monotonous, revealing that there are no or very few areas corresponding to the penetration area. In other words, the arc welding is judged to be defective.

[0054] In the state of low penetration shown in Figure 11, the spacing between the surface patterns is wider in the photograph of Figure 11(B) compared to Figure 10(B), but the size (amount of penetration) of the penetration area in Figure 11(A) (see reference numeral 24 in Figures 2 and 3) is small. The spectroscopic image of Figure 11(C) shows a pattern that does not exist in Figure 9, and the appearance of the penetration area is clear from the spectroscopic image. However, because the amount of penetration itself is small, the arc welding is judged to be defective.

[0055] In the state of high penetration in Figure 12, the spacing between the surface patterns is wider than in the photograph of Figure 12(B) compared to Figure 11(B), and the size (amount of penetration) of the penetration area in Figure 12(A) (see reference numeral 24 in Figures 2 and 3) is larger. In the spectroscopic image of Figure 12(C), the pattern of the area corresponding to the penetration area appears large, and the appearance and size of the penetration area are clear from the spectroscopic image. In the state of high penetration in Figure 11, the arc welding is judged to be good.

[0056] In the welding quality judgment device 1 of the embodiment, the wavelength of the electromagnetic wave is selected according to the welding condition to be judged (the object of judgment). When selecting, the electromagnetic wave is not limited to one specific wavelength, but may be multiple electromagnetic waves (light) with different wavelengths. The spectral image (waveform of spectral reflectance) when irradiated onto the welded area changes depending on the wavelength. Therefore, by combining multiple electromagnetic waves (light) with different wavelengths, the sensitivity of evaluation and judgment is improved. Note that even when multiple wavelengths of electromagnetic waves are irradiated from the irradiation unit, the selection unit 120 holds a combination of wavelengths based on the welding condition and selects each individual wavelength.

[0057] In this embodiment, the electromagnetic waves of the predetermined wavelengths are of two types: electromagnetic waves in the blue to ultraviolet wavelength band (e.g., 200 to 400 nm) and electromagnetic waves in the near-infrared wavelength band (e.g., 700 to 900 nm). In the photographs of Figure 13, the upper row is a photograph of the welded area when irradiated with electromagnetic waves (light) of a wavelength of 400 nm, and the lower row is a photograph of the welded area when irradiated with electromagnetic waves (light) of a wavelength of 800 nm. The welded areas in both photographs are the same.

[0058] When irradiated with ultraviolet light at a wavelength of 400 nm in the upper photograph, the vicinity of the weld (see reference numeral 21 in Figures 2 and 3) is clearly visible. In contrast, when irradiated with near-infrared light at a wavelength of 800 nm in the lower photograph, the weld (see reference numeral 20 in Figures 2 and 3) is clearly visible.

[0059] Figure 14 is a schematic diagram showing the spectral reflectance graphs corresponding to two wavelengths: 400 nm (dashed line) and 800 nm (solid line). Although the graphs show roughly similar behavior, the waveforms differ in detail. For example, by combining different wavelengths for determining the penetration amount, oxide film thickness, base metal penetration, and throat depth, it is possible to obtain sensitivity according to the characteristics of each part, which is convenient.

[0060] As a result, by combining multiple electromagnetic waves (light) with different wavelengths, the sensitivity of evaluation and judgment of welded areas is improved.

[0061] The flowchart in Fig. 15 shows the overall flow of the method for determining the welding quality of arc welding in the processing unit 10 (CPU 11), and includes various steps such as a welding state acquisition step (S110), a selection step (S120), an irradiation instruction step (S130), a distribution generation step (S140), an image acquisition step (S150), a determination step (S160), and an output step (S170). Of course, various steps necessary for the operation of the processing unit 10 itself are naturally included. The flowchart in Fig. 14 is configured to include the output step (S170). Alternatively, the configuration in Fig. 14 may be configured to omit the output step (S170).

[0062] The welding condition acquisition function detects the wavelength reflected from the welded portion 20 and the vicinity of the welded portion 21 after arc welding via the detection unit 3, and acquires the welding condition of the welded portion 20 and the vicinity of the welded portion 21 (S110; welding condition acquisition step). The selection function stores in advance combinations of the welding condition occurring in the welded portion 20 and the vicinity of the welded portion 21 after arc welding and the wavelength of the electromagnetic wave to be irradiated to the welded portion 20 and the vicinity of the welded portion 21, and selects the wavelength of the electromagnetic wave to be irradiated from the irradiation unit 2 based on the welding condition to be determined (the welding condition to be determined) (S120; selection step). The irradiation instruction function generates an instruction to irradiate the electromagnetic wave of the selected wavelength from the irradiation unit 2 (S130; irradiation instruction step).

[0063] The distribution generation function acquires the reflection spectrum of the welded portion 20 and the vicinity of the welded portion 21 after arc welding to generate a spectral distribution (S140; distribution generation step). The image acquisition function acquires an image of the welded portion after arc welding captured by the imaging unit 4 (S150; image acquisition step). The determination function determines the welding quality based on the spectral distribution along the scanning direction of the welded portion 20 and the vicinity of the welded portion 21 after arc welding (S160; determination step). The output function outputs the result of the determination of the welding quality (S17; output step).

[0064] The computer program of the present invention described above may be recorded on a processor-readable recording medium, and the recording medium may be a "non-transitory tangible medium" such as a tape, disk, card, semiconductor memory, programmable logic circuit, etc.

[0065] The computer program can be implemented using, for example, a scripting language such as ActionScript or JavaScript (registered trademark), an object-oriented programming language such as Objective-C or Java (registered trademark), or a markup language such as HTML5. [Explanation of symbols]

[0066] 1. Arc welding quality assessment device 2. Irradiation unit 3. Detection unit 4. Photography Department 10 Processing unit (computer) 11 CPU 12 ROM 13 RAM 14 Storage section 15 Input / Output Interfaces 16 Display 17 Keyboard 18 Mouse 20 Welded section 21 Near the weld 22 End 23 Meat Section 24 Welding section 25 Oxide film 110 Welding status acquisition unit 120 Selection Section 130 Irradiation instruction section 140 Distribution generator 150 Image acquisition unit 160 Judgment section 170 Output section W1 First member W2 Second member

Claims

1. Apparatus for determining the quality of arc welding of a welded portion formed by arc welding a first member and a second member And, The welding quality judgment device includes: an irradiation unit that irradiates the welded portion and the vicinity of the welded portion with electromagnetic waves of a predetermined wavelength; a detection unit that irradiates the electromagnetic wave and detects a wavelength reflected from the welded portion and the vicinity of the welded portion; a processing unit that generates a reflection spectrum of the reflection wavelength detected by the detection unit, The processing unit a welding condition acquisition unit that detects, via the detection unit, a reflected wavelength reflected from the welded portion and the vicinity of the welded portion after arc welding, and acquires a welding condition of the welded portion and the vicinity of the welded portion; a selection unit that stores in advance a combination of a welding state occurring at the welded portion and the vicinity of the welded portion after arc welding and a wavelength of an electromagnetic wave to be irradiated to the welded portion and the vicinity of the welded portion, and selects a wavelength of the electromagnetic wave to be irradiated from the irradiation unit based on the acquired welding state; an irradiation instruction unit that generates an instruction to irradiate the electromagnetic wave of the selected wavelength from the irradiation unit; a distribution generating unit that acquires the reflection spectrum of the welded portion and the vicinity of the welded portion after arc welding and generates a spectral distribution at a position along a scanning direction of the welded portion and the vicinity of the welded portion; a determination unit that determines welding quality based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding. A welding quality judgment device for arc welding characterized by:

2. 2. The welding quality judgment device for arc welding according to claim 1, wherein the judgment unit estimates the amount of penetration that has occurred in the first member and the second member based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding, and judges the welding quality.

3. 3. The welding quality determination device for arc welding according to claim 2, wherein the determination unit determines the welding quality based on a correspondence table in which combinations of the first member and the second member correspond to arc welding conditions for the first member and the second member, and which shows an association between the spectral distribution and the penetration amount.

4. 4. The welding quality determination device for arc welding according to claim 1, wherein the first member and the second member are made of the same type of metallic material.

5. 5. The welding quality determination device for arc welding according to claim 1, wherein the electromagnetic waves of the predetermined wavelength are a plurality of electromagnetic waves having mutually different wavelengths.

6. 5. The welding quality judgment device for arc welding according to claim 1, wherein the electromagnetic waves of the predetermined wavelengths are of two types: electromagnetic waves in the wavelength band of blue to ultraviolet light, and electromagnetic waves in the wavelength band of near-infrared light.

7. the detection unit of the quality assessment device includes an imaging unit that images the welded portion and the vicinity of the welded portion formed by the first member and the second member after arc welding, The processing unit includes an image acquisition unit that acquires an image of a welded portion after arc welding captured by the imaging unit, The welding quality determination device for arc welding according to claim 1 , wherein the distribution generation unit superimposes an image of the spectral distribution on the image of the welded portion.

8. The welding quality determination device for arc welding according to claim 1 , wherein the processing unit includes an output unit that outputs the result of the determination of the welding quality.

9. A welding quality evaluation method for an arc welding welding quality evaluation device for an arc welding portion produced by arc welding a first member and a second member, comprising: The welding quality judgment device includes: an irradiation unit that irradiates the welded portion and the vicinity of the welded portion with electromagnetic waves of a predetermined wavelength; a detection unit that irradiates the electromagnetic wave and detects a wavelength reflected from the welded portion and the vicinity of the welded portion; a processing unit that generates a reflection spectrum of the reflection wavelength detected by the detection unit, The processing unit a welding state acquisition step of detecting, via the detection unit, a reflected wavelength reflected from the welded portion and the vicinity of the welded portion after arc welding, and acquiring a welding state of the welded portion and the vicinity of the welded portion; a selection step of storing in advance a combination of a welding state occurring at the welded portion and the vicinity of the welded portion after arc welding and a wavelength of an electromagnetic wave to be irradiated to the welded portion and the vicinity of the welded portion, and selecting a wavelength of the electromagnetic wave to be irradiated from the irradiation unit based on the acquired welding state; an irradiation instruction step of generating an instruction to irradiate the electromagnetic wave of the selected wavelength from the irradiation unit; a distribution generating step of acquiring the reflection spectrum of the welded portion and the vicinity of the welded portion after arc welding and generating a spectral distribution at a position along a scanning direction of the welded portion and the vicinity of the welded portion; a determining step of determining welding quality based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding. A method for determining the welding quality of arc welding.

10. A welding quality determination program for an arc welding welding quality determination device for a welded portion produced by arc welding a first member and a second member, The welding quality judgment device includes: an irradiation unit that irradiates the welded portion and the vicinity of the welded portion with electromagnetic waves of a predetermined wavelength; a detection unit that irradiates the electromagnetic wave and detects a wavelength reflected from the welded portion and the vicinity of the welded portion; a processing unit that generates a reflection spectrum of the reflection wavelength detected by the detection unit; Equipped with The processing unit a welding state acquisition function that acquires a welding state of the welded portion and the vicinity of the welded portion by detecting a reflected wavelength reflected from the welded portion and the vicinity of the welded portion after arc welding through the detection unit; a selection function that stores in advance a combination of a welding state occurring at the welded portion and the vicinity of the welded portion after arc welding and a wavelength of an electromagnetic wave to be irradiated to the welded portion and the vicinity of the welded portion, and selects a wavelength of the electromagnetic wave to be irradiated from the irradiation unit based on the acquired welding state; an irradiation instruction function that generates an instruction to irradiate the electromagnetic wave of the selected wavelength from the irradiation unit; a distribution generation function that acquires the reflection spectrum of the welded portion and the vicinity of the welded portion after arc welding and generates a spectral distribution at a portion of the welded portion and the vicinity of the welded portion along a scanning direction; and a judgment function for judging the welding quality based on the spectral distribution along the scanning direction of the welded portion and the vicinity of the welded portion after arc welding. A welding quality judgment program for arc welding, characterized by:

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