Inspection equipment and welding equipment

Abstract

Provided are an inspection device and a welding device capable of more appropriately inspecting a welding state. The inspection device of an embodiment includes an imaging unit and a processing unit. The imaging unit acquires first image data obtained by imaging a first welded portion under a first condition, and second image data obtained by imaging the first welded portion under a second condition different from the first condition. The first welded portion includes a first non-welded region, a second non-welded region, and a first welded region between the first and second non-welded regions. The processing unit performs a first inspection of the first welded portion based on a result of detecting a first boundary between the first non-welded region and the first welded region based on the first image data, and a result of detecting a second boundary between the first and second non-welded regions based on the second image data.

Description

Technical Field

[0001] Embodiments of the present invention relate to an inspection device and a welding device. Background Art

[0002] Welding is performed using a laser or the like. It is desirable to more appropriately check the welding state. For example, by appropriately checking the welding state, more appropriate welding can be achieved.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 6-8564 Summary of the Invention

[0006] Embodiments of the present invention provide an inspection device and a welding device capable of more appropriately inspecting a welding state.

[0007] An inspection device according to an embodiment includes an imaging unit and a processing unit. The imaging unit acquires first image data obtained by imaging a first weld under a first condition, and second image data obtained by imaging the first weld under a second condition different from the first condition. The first weld includes a first non-welded area, a second non-welded area, and a first welded area between the first and second non-welded areas. The processing unit performs a first inspection of the first weld based on a result of detecting a first boundary between the first non-welded area and the first welded area based on the first image data and a result of detecting a second boundary between the first and second non-welded areas based on the second image data. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram illustrating an inspection device according to an embodiment.

[0009] Figure 2 This is a schematic plan view of an inspection object inspected in the inspection apparatus according to the exemplary embodiment.

[0010] Figure 3 This is a schematic diagram illustrating the operation of the inspection device according to the embodiment.

[0011] Figure 4 This is a schematic diagram illustrating the operation of the inspection device according to the embodiment.

[0012] Figure 5 This is a schematic diagram illustrating the operation of the inspection device according to the embodiment.

[0013] Figure 6 It is a schematic diagram illustrating the operation of the inspection device according to the embodiment.

[0014] Figure 7 This diagram explains how to inspect the weld area for holes and cracks.

[0015] Figure 8 This is an explanatory diagram for detecting the presence or absence of deviation.

[0016] Figure 9 This is a flowchart illustrating the operation of inspection processing in the inspection device according to the embodiment.

[0017] Figure 10 This is a flowchart illustrating details of the operation of the inspection process in the inspection device according to the embodiment.

[0018] Figure 11 It is a schematic diagram illustrating an inspection device according to an embodiment.

[0019] Figure 12 Schematic diagram illustrating a welding device according to an embodiment.

[0020] Figure 13 This is a graph showing a calibration curve that illustrates an example of the relationship between the weld width and the laser power in a welding device. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. may not necessarily be the same as in reality. Even when showing the same part, the size and ratio may be shown differently depending on the drawing.

[0023] In the present specification and the drawings, the same elements as those already described are denoted by the same reference numerals, and detailed description thereof will be appropriately omitted.

[0024] (First embodiment)

[0025] Figure 1 Schematic diagram illustrating the structure of an inspection device according to an embodiment. The inspection device according to this embodiment inspects a plurality of welded portions included in an inspection object one by one.

[0026] like Figure 1 As shown, the inspection device 10 includes an illumination unit 11 , an imaging unit 12 , a processing unit 13 , and a storage unit 14 .

[0027] The lighting unit 11 irradiates light onto the welded portion of the inspection object M placed on the table 15 so that a clearer image can be obtained by the imaging unit 12. As the lighting unit 11, for example, a multi-angle ring light can be used.

[0028] The imaging unit 12 captures each of the multiple welds included in the inspection object M placed on the worktable 15. The imaging unit 12 includes, for example, a camera such as a CCD image sensor or a CMOS image sensor. The imaging unit 12 includes an imaging control unit. The imaging control unit sets the camera's imaging conditions and controls the camera.

[0029] The imaging unit 12 captures the welded portion illuminated by the illumination unit at least twice under different imaging conditions. This generates at least two sets of image data (first image data and second image data) captured under different imaging conditions (first and second conditions) for a single welded portion. This image data is stored in the storage unit 14. The imaging conditions include, for example, the exposure time during imaging by the imaging unit and the illumination intensity of the welded portion. Details on setting imaging conditions will be described later.

[0030] The processing unit 13 detects the weld mark in the welded portion as the welded area based on at least two image data captured by the imaging unit 12. The processing unit 13 inspects the welded portion based on the image data of the welded area. Specifically, the processing unit 13 detects the boundary between the welded area and the non-welded area in the welded portion to detect the welded area.

[0031] The processing unit 13 calculates the brightness value of pixels included in each of the at least two image data captured by the imaging unit 12. In each image, pixels (edges) with significant brightness changes are detected as the boundary between the weld area and the non-weld area. In this way, the processing unit 13 detects a first boundary based on the first image data and a second boundary based on the second image data. Thus, the weld area is detected based on the first and second image data.

[0032] The processing unit 13 inspects the weld quality based on the brightness of pixels corresponding to the weld area in the image data. The weld inspection includes, for example, evaluation of the adequacy of the weld width and evaluation of the presence of holes, cracks, deviations, and lift.

[0033] Details regarding the contents of image processing and inspection such as weld area detection in the processing unit 13 will be described later.

[0034] The storage unit 14 stores parameters used during inspection by the processing unit 13. The storage unit 14 stores images captured by the imaging unit 12, inspection results by the processing unit 13, and the like.

[0035] (Regarding filming conditions)

[0036] Figure 2 This is a schematic plan view showing an electric module as an example of an inspection target object inspected by the inspection apparatus of this embodiment. Figure 3 as well as Figure 4 This is an example of the image captured by the imaging unit of the inspection device of this embodiment. Figure 2 Figure 1 is an image of a welding portion included in an electrical module.

[0037] like Figure 2 As shown, the electrical module of the object to be inspected M includes multiple parts (in Figure 2 In the example, there are 48 welding parts. Figure 3 and Figure 4 As shown in FIG, each welding portion of the electric module is annular. Figure 2 The imaging conditions when inspecting the electrical module shown as the object M will be described. Figure 2 As shown in (b), a number i is pre-assigned to a plurality of welded locations in the inspection object M. When the inspection device 10 is used for inspection, the captured images, imaging conditions, evaluation results, and measured values ​​are stored in the storage unit 14 in association with the welded location number i.

[0038] The imaging unit 12 performs at least two imaging operations on a single weld under different imaging conditions (a first condition and a second condition) to obtain at least two sets of image data (a first image data and a second image data). In this embodiment, as an example of imaging conditions, the imaging unit 12 performs multiple imaging operations with different exposure times.

[0039] Figure 3 An example of obtaining two images by making the exposure time different is shown. Figure 3 In the figure, the upper part is an example of an image (first image data) obtained by photographing with an exposure time of 1 ms (first condition), and the lower part is an example of an image (second image data) obtained by photographing with an exposure time of 2 ms (second condition).

[0040] exist Figure 3 In the example shown, the weld area is annular and has fine irregularities. Therefore, due to the image capture conditions (exposure time), there is a difference in brightness between the area inside the ring (the first non-weld area) and the area outside the ring (the second non-weld area). Therefore, the preferred image for measuring the inner contour (inner diameter) of the weld area differs from the preferred image for measuring the outer contour (outer diameter).

[0041] like Figure 3 As shown, for example, in the image captured at 1ms, the difference in brightness between the inner side of the weld area (inner than the ring), that is, the first non-weld area, and the weld area is large, and the boundary is clear, so it is suitable for measuring the inner contour line (inner diameter) of the weld area ( Figure 3On the other hand, the image captured at 1ms has a blurred portion outside the weld area (outside the ring), that is, the boundary between the second non-weld area and the weld area ( Figure 3 The arrow A) in FIG. 1 is not suitable for measuring the outer contour line (outer diameter) of the welding area.

[0042] In the image captured at 2ms, the difference in brightness between the second non-weld area and the weld area (outside the ring) is large, and the boundary is clear, so it is suitable for measuring the outer contour line (outer diameter) of the weld area. On the other hand, in the image captured at 2ms, the brightness of the inner side of the weld area (inside the ring) is about the same as that of the weld area, and there is a part with unclear boundary ( Figure 3 Therefore, the image captured at 2 ms is not suitable for measuring the inner contour line (inner diameter) of the weld area.

[0043] By using multiple images captured with different exposure times, the inner and outer diameters of the weld area can be accurately measured. This allows for accurate detection of the weld area. The imaging unit 12 captures multiple images using different imaging conditions, for example, by varying the illumination intensity of the light emitted by the illumination unit 11.

[0044] In the inspection device 1, Figure 1 The electrical module is placed on the workbench 15, and the workbench is moved to take pictures of the welding parts one by one and inspect them one by one. Figure 2 As shown, the electrical module has wall-like components on all four sides. Therefore, when captured under the same imaging conditions, the images obtained for welds w2 along the sides and w3 at the corners appear darker than for weld w1 at the center of the electrical module.

[0045] Figure 4 The upper part of the diagram shows an image obtained by photographing the electrical module with an exposure time of 1 ms. Figure 4 The upper part of FIG shows, from the left, an image of the welded portion w1 in the center of the electric module, an image of the welded portion w2 along the side, and an image of the welded portion w3 at the corner. Figure 4 As shown, the image of the weld w2 along the side and the image of the weld w3 located at the corner are dark images with low brightness values ​​as a whole, compared to the image of the weld w1 at the center.

[0046] Therefore, in the imaging unit 12 , it is preferable to perform imaging while changing imaging conditions according to the position of the welded portion in the inspection object M. This makes it possible to obtain an image more suitable for detecting the welded region.

[0047] exist Figure 4The lower part shows an example of an image captured by changing the exposure time according to the position of the weld part. Figure 4 The left end of the lower row shows an example of an image obtained by capturing the weld portion w1 in the center with an exposure time of 1 ms. Figure 4 The center of the lower row shows an example of an image obtained by capturing the weld portion w2 along the side with an exposure time of 1.4 ms. Figure 4 The right end of the lower row shows an example of an image obtained by capturing the weld portion w3 located at the corner with an exposure time of 2 ms.

[0048] In this way, the imaging unit 12 switches the imaging conditions according to the position of the welded portion to be inspected, and captures the welded portion multiple times under different imaging conditions to obtain at least two pieces of image data. This allows for highly accurate detection of the welded region.

[0049] (About Inspection in Processing Department)

[0050] Next, the inspection process in the processing unit 13 will be described.

[0051] The weld inspection performed by the processing unit 13 includes, for example, inspections regarding whether welding has been performed, whether the weld width is appropriate, and inspections regarding the presence or absence of holes, cracks, deviations, and lifts.

[0052] (1) Inspection related to non-welding

[0053] Figure 5 This diagram explains how to check whether a weld has been completed.

[0054] The processing unit 13 selects a single image data item from the plurality of image data items captured by the imaging unit 12 to be used for inspecting whether the welded portion is welded. For example, the first image data item captured with a short exposure time is used. The processing unit 13 sets an initial circle for the first image data item so that it encompasses the welded portion to be measured. The processing unit 13 calculates the brightness value of each pixel within the initial circle in the first image data item, and calculates the area or volume (area x average brightness value) of high-brightness regions with brightness values ​​exceeding a threshold.

[0055] Processing unit 13 evaluates welds where the area or volume of the high-brightness region exceeds a predetermined value as welded. On the other hand, welds where the area or volume of the high-brightness region is less than the predetermined value are evaluated as unwelded. If unwelded, the welds are evaluated as requiring welding. The evaluation results are stored in storage unit 14.

[0056] (2) Inspection related to the width of the weld area (thinning, lifting)

[0057] The processing unit 13 calculates the brightness value of each pixel in each of the two images captured by the imaging unit 12. As described above, when the weld area is annular, the image captured with the shorter exposure time (the first image) of the two images is used to measure the inner diameter of the weld area. Furthermore, the image captured with the longer exposure time (the second image) is used to measure the outer diameter of the weld area.

[0058] Figure 6 This diagram illustrates the measurement of the inner diameter contour line 41, outer diameter contour line 42, and width of the weld area. Processing unit 13 calculates the center of the weld area and sets an initial circle on the weld area from this center. Processing unit 13 searches for pixels (edges) with significant changes in brightness values ​​in radial directions from the center of the initial circle to estimate the ends of the weld area. More specifically, inner diameter contour line 41 and outer diameter contour line 42 of the weld area are estimated based on the Euclidean distance from the center coordinates of the initial circle to the coordinates of the ends of the weld area. Processing unit 13 detects the weld area in this manner.

[0059] The processing unit 13 calculates the difference between the outer diameter contour line 42 and the inner diameter contour line 41 at 0.5-degree intervals based on the center of the initial circle as the width (weld width) for each angle. The processing unit 13 calculates the average value of the difference between the outer diameter contour line 42 and the inner diameter contour line 41 at each angle for a total of 720 locations around the entire circumference and stores this average value in the storage unit 14 as the width d of the weld area.

[0060] If the calculated width d of the weld region is within a predetermined range of values, the processing unit 13 evaluates the width d of the weld region as appropriate. If the width d of the weld region is outside the predetermined range, the processing unit 13 evaluates the width d of the weld region as inappropriate. The evaluation results are stored in the storage unit 14. Regardless of whether the measured width d of the weld region is appropriate, it is stored in the storage unit 14 in association with the weld part number i.

[0061] When the width d of the weld region is inappropriate, the processing unit 13 evaluates whether the weld region is thin or too thick.

[0062] The processing unit 13 determines whether the maximum and minimum values ​​of the calculated weld widths at each angle at 720° are within a predetermined range to evaluate whether the weld is thinning or too thick. Specifically, the processing unit 13 evaluates the weld as thinning if either the maximum or minimum value is smaller than the predetermined range, and evaluates the weld as too thick if either value is larger than the predetermined range.

[0063] If the weld area is thin, it is evaluated that re-welding is necessary. On the other hand, if the weld area is too thick, it is evaluated that visual confirmation by the operator is necessary.

[0064] Furthermore, the processing unit 13 can also use the average, maximum, and minimum values ​​of the distances from the center of the initial circle to each point of the inner diameter contour line 41 or the outer diameter contour line 42 to evaluate whether the width d of the weld region is appropriate, narrow, or too thick.

[0065] In addition, the processing unit 13 calculates the weld width at each angle, and uses a portion of the 720 points as an area outside the measurement target of the weld width. Figure 6 As shown in FIG. 1 , when there is a weld area that is protruding from the annular weld area, it is sometimes impossible to accurately measure the inner diameter contour line 41 or the outer diameter contour line 42. Figure 6 As shown, the non-measurement target region 45 is determined, and the processing unit 13 can also not calculate the weld width for the non-measurement target region 45 .

[0066] The processing unit 13 inspects whether or not there is floating in the weld portion evaluated as having thinning in the above-mentioned thinning inspection.

[0067] The processing unit 13 selects a single image data set from the multiple image data sets captured by the imaging unit 12 to be used for inspection for the presence of lifting. For example, the first image data set captured with a short exposure time is used. The processing unit 13 sets an initial circle for the first image data set so that the welded portion to be measured is included. The processing unit 13 calculates the brightness value of each pixel within the initial circle in the first image data set and calculates the area of ​​the low-brightness region with brightness values ​​below a threshold. Welded portions with a low-brightness region area greater than a predetermined value are evaluated as having lifting.

[0068] (3) Inspection related to the presence of holes and cracks

[0069] Figure 7 This diagram explains how to inspect the weld area for holes and cracks.

[0070] The processing unit 13 draws an inner diameter contour average radius circle 51 and an outer diameter contour average radius circle 52 based on the inner diameter contour line 41 and the outer diameter contour line 42 measured when calculating the width d of the weld region. In this case, the inner diameter contour average radius circle 51 is a circle drawn with a radius equal to the value obtained by adding a predetermined constant A to the average radius of the inner diameter contour line 41. The outer diameter contour average radius circle 52 is a circle drawn with a radius equal to the value obtained by adding a predetermined constant B to the average radius of the outer diameter contour line 42. Both the inner diameter contour average radius circle 51 and the outer diameter contour average radius circle 52 are drawn with the centroid coordinates of the outer diameter contour line 42 as their centers.

[0071] Processing unit 13 calculates the brightness value of each pixel within the annular region between mean radius circle 51 of the inner diameter contour and mean radius circle 52 of the outer diameter contour, and calculates the area of ​​the low-brightness partial region with brightness values ​​below a threshold. If the area of ​​a partial region exceeds a predetermined threshold, the partial region is detected as a hole, dent, or crack. If a hole, dent, or crack exists, it is determined that re-welding is necessary. The evaluation results are stored in storage unit 14.

[0072] (4) Inspection related to the presence or absence of deviation

[0073] Figure 8 This is an explanatory diagram for detecting the presence or absence of deviation.

[0074] The processing unit 13 uses the center of gravity of the outer diameter contour line 42 as the center of gravity position of the weld area and measures the deviation from the ideal center of gravity position. Here, the ideal center of gravity position is the center of gravity position of the outer diameter contour line in a reference image of a pre-registered qualified product. If the Euclidean distance between the two center of gravity positions is greater than a predetermined value, the processing unit 13 evaluates the weld area as deviating and stores the evaluation result in the storage unit 14.

[0075] Below, use Figure 9 as well as Figure 10 The flowchart of FIG. 1 illustrates the inspection process of the inspection device configured in this manner.

[0076] Figure 9 This is a flowchart illustrating the operation of the inspection process in the inspection device according to the embodiment. Figure 10 This is a flowchart illustrating details of the operation of the inspection process in the inspection device according to the embodiment.

[0077] like Figure 9 As shown, when the inspection object M is placed on the worktable 15 of the inspection device 10 , multiple welded portions included in the inspection object M are inspected one by one. In step S101 , the processing unit 13 moves the worktable 15 so that the welded portion of the inspection object is included in the field of view of the imaging unit 12 .

[0078] In step S102, the illumination unit 11 illuminates the welded portion, for example, so that the welded area is brightly imaged and the remaining area is darkly imaged. The imaging unit 12 acquires at least two images of the welded portion to be inspected, using different imaging conditions. Specifically, the imaging unit 12 acquires a first image of the welded portion captured under a first imaging condition (e.g., an exposure time of 1 ms) and a second image captured under a second imaging condition (e.g., an exposure time of 2 ms).

[0079] In step S103, the processing unit 13 inspects the welded portion using the two images captured by the imaging unit 12. The detailed operation of the inspection process will be described later.

[0080] In step S104, when the inspection of the welded portion is completed, the processing unit 13 determines whether the inspection of all welded portions (all positions) included in the inspection object M has been completed, and repeats the above-mentioned process until the inspection of all welded portions is completed. When the inspection of all welded portions is completed, the inspection process ends.

[0081] like Figure 6 As shown, the processing unit 13 performs an inspection using the first and second image data captured by the imaging unit 12. During this inspection, the weld status is classified into three categories: "Weld OK," "NG1," and "NG2." Specifically, "Weld OK" indicates a satisfactory weld status. "NG1" indicates an inadequate weld status and indicates a location that requires re-welding. "NG2" indicates an inadequate weld status and indicates a location that requires operator confirmation.

[0082] The processing unit 13 follows Figure 10 Check and process according to the flowchart shown. Figure 10 As shown, first, the processing unit 13 checks whether the welded portion to be inspected is not welded (step S201). During this inspection, if the welded portion is evaluated as not welded, the process proceeds to NG1 in step S208, where the evaluation result is stored in the storage unit 14, and the inspection of the welded portion is terminated. If the welded portion is evaluated as welded, the process proceeds to the next step S202.

[0083] In step S202, the weld region is detected from the welded portion, and the width of the detected weld region is measured to evaluate whether the width of the weld region is appropriate. If the width of the weld region is inappropriate, the process proceeds to step S203. If the width of the weld region is appropriate, the process proceeds to step S205. Whether the width of the weld region is appropriate or not is stored in the storage unit 14.

[0084] In step S203, the weld region is evaluated as being thin or thick relative to its proper width. If the weld region is thin, the process proceeds to step S204. If the weld region is thick, the process proceeds to step S209, where the result is NG2. In step S204, the processing unit 13 checks whether the weld region has any floating. If the weld region has any floating, the processing unit 13 proceeds to step S209, where the result is NG2; if the weld region has no floating, the processing unit 13 proceeds to step S208, where the result is NG1. In either case, the processing unit 13 stores the evaluation results for the weld region in the storage unit 14, and the inspection of the weld region is terminated.

[0085] In step S205, the processing unit 13 inspects the weld region for holes or cracks. If holes or cracks are found in the weld region, the processing unit 13 proceeds to step S208 (NG1), terminating the inspection of the weld region. If holes or cracks are found in the weld region, the processing unit 13 proceeds to step S206.

[0086] In step S206, the processing unit 13 checks whether the weld area is displaced. If the weld area is displaced, the processing unit 13 proceeds to step S209 at NG2, ending the inspection of the weld area. If the weld area is not displaced, the processing unit 13 proceeds to step S207.

[0087] In step S207, the welded portion to be inspected is evaluated as suitable in all the inspections from step S201 to step S206 by the processing unit 13. Therefore, the processing unit 13 stores the evaluation result of "weld OK" for the welded portion in the storage unit 14 and ends the inspection.

[0088] Figure 11 It is a schematic diagram illustrating the hardware configuration of the inspection device according to the embodiment.

[0089] The inspection device includes a central processing unit (CPU) 111 , an input device 112 , an output device 113 , a ROM (Read Only Memory) 114 , a RAM (Random Access Memory) 115 , a storage device 116 , a communication device 117 , and a bus 118 . The various components are connected via the bus 118 .

[0090] The CPU 111 includes a processing circuit. The CPU 111 cooperates with various programs pre-stored in the ROM 114 or the storage device 116 to execute various processes and centrally control the operation of the inspection device 10. This realizes the functions of the processing unit 13 in the inspection device described above. The CPU 111 uses a specified area of ​​the RAM 115 as a work area during processing. The CPU 111 cooperates with programs pre-stored in the ROM 114 or the storage device 116 to implement the input device 112, output device 113, and communication device 117.

[0091] The input device 112 includes, for example, a keyboard, a mouse, or a touch panel. The input device 112 receives information input from the user as an instruction signal and outputs the instruction signal to the CPU 111. The output device 113 is, for example, a monitor. Based on the signals output from the CPU 111, the output device 113 outputs various information in a visually recognizable form.

[0092] ROM 114 stores programs and various setting information used to control the inspection device 10 in a non-rewritable format. RAM 115 is a volatile storage medium such as SDRAM (Synchronous Dynamic Random Access Memory). RAM 115 functions as a work area for CPU 111. Specifically, it functions as a buffer for temporarily storing various variables and parameters used by the inspection device 10.

[0093] The storage device 116 is a rewritable recording device such as a semiconductor storage medium such as a flash memory or a magnetically or optically recordable storage medium. The storage device 116 stores programs used to control the inspection apparatus 10 and various setting information. The communication device 117 is used to communicate with external devices and transmit and receive information.

[0094] (Second embodiment)

[0095] By feeding back the inspection results of the above-mentioned inspection device to the welding device that performs laser welding, it is possible to control the laser output.

[0096] Figure 12 Schematic diagram illustrating a welding device according to this embodiment. Figure 12 As shown, welding apparatus 20 includes a laser output unit 22 for irradiating a welding object 25 placed on a worktable 21 with laser light, a control unit 23 for controlling laser output unit 22, and a storage unit 24. The control unit 23 calculates the output of laser output unit 22 and a correction amount for correcting the output.

[0097] Figure 13 This is a graph showing a calibration curve that shows an example of the relationship between the weld width and the laser output in the welding device 20. The welding device 20 holds the calibration curve in advance in the storage unit 24, etc., and performs welding by using the laser output based on the calibration curve. Figure 13 As shown, the calibration curve is represented by D=ap, where D is the weld width, P is the laser output, and a is a constant.

[0098] The laser correction amount can be calculated as follows. First, the average weld width D is calculated as the average value of the widths d of multiple weld regions included in the inspection object M obtained by the inspection device 10. The laser correction amount ΔP is calculated based on the difference between the appropriate weld width Dtarget and the average weld width D.

[0099] The calculation of the laser correction amount can also be performed in the inspection device 10 .

[0100] Thus, according to this embodiment, at least two image data sets are captured under different imaging conditions for the welded portion to be inspected, and the contour of the welded region is measured using images that are selectively appropriate for the inner and outer contours of the welded region. The width of the welded region is measured based on the contours of the welded region thus measured, thereby enabling the width of the welded region to be measured with high precision, and the weld condition to be accurately inspected. Based on the highly precisely measured width of the welded region, the laser output during welding can be corrected to an appropriate value.

[0101] According to the above-described embodiments, it is possible to accurately inspect the welding state of the welded portion and optimize the parameters during welding.

[0102] The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples. For example, the specific configuration of each element included in the inspection device is encompassed within the scope of the present invention as long as a person skilled in the art can similarly implement the present invention and achieve the same effect by appropriately selecting from known configurations.

[0103] Furthermore, any combination of two or more elements of each specific example within a technically feasible range is included in the scope of the present invention as long as it includes the gist of the present invention.

[0104] Furthermore, as embodiments of the present invention, all inspection devices that can be appropriately designed and modified by those skilled in the art based on the above-described inspection device are within the scope of the present invention as long as they include the gist of the present invention.

[0105] Furthermore, within the scope of the concept of the present invention, those skilled in the art can conceive of various changes and modifications, and these changes and modifications are also understood to fall within the scope of the present invention.

[0106] While several embodiments of the present invention have been described, these embodiments are provided as examples and are not intended to limit the scope of the invention. These novel embodiments may be implemented in various other ways, and various omissions, substitutions, and modifications may be made without departing from the spirit of the invention. These embodiments and their variations are intended to be included within the scope and spirit of the invention and within the scope of the invention set forth in the claims and their equivalents.

[0107] Description of Reference Numerals

[0108] 10…inspection device, 11…illumination unit, 12…camera unit, 13…processing unit, 14…storage unit, 15…workbench, 41…inner diameter contour line, 42…outer diameter contour line, 51…average radius circle of inner diameter contour, 52…average radius circle of outer diameter contour, 112…input device, 113…output device, 116…storage device, 117…communication device, 118…bus, w1 to w3…welding unit.

Claims

1. An inspection device comprising: an imaging unit that acquires first image data obtained by imaging a first weld portion under a first condition and second image data obtained by imaging the first weld portion under a second condition different from the first condition, wherein the first weld portion includes a first non-weld region, a second non-weld region, and a first annular weld region between the first and second non-weld regions, the first weld region exists outside the first non-weld region, the second non-weld region exists outside the first weld region, and the first non-weld region is smaller than the second non-weld region; and The processing unit performs a first check on an inner contour line of the annular first welding region based on a result of detecting a first boundary between the first non-welding region and the first welding region based on the first image data, performs a first check on an outer contour line of the annular first welding region based on a result of detecting a second boundary between the first welding region and the second non-welding region based on the second image data, and calculates a distance, i.e., a width, between the inner contour line and the outer contour line of the first welding region based on the first boundary and the second boundary.

2. The inspection device according to claim 1, wherein: The first condition and the second condition are exposure times when the imaging unit is performing imaging. The exposure time of the first condition is shorter than the exposure time of the second condition.

3. The inspection device according to claim 1, wherein: The first condition and the second condition are illumination at the first welding portion when the imaging unit is performing imaging. The illuminance under the first condition is lower than the illuminance under the second condition.

4. The inspection device according to claim 1, wherein: The processing unit further performs a second inspection on the first weld portion based on at least one of a first distribution of brightness of pixels corresponding to the first weld region in the first image data and a second distribution of brightness of pixels corresponding to the first weld region in the second image data.

5. The inspection device according to claim 4, wherein: The processing unit calculates a size of the first weld region based on at least one of the first distribution and the second distribution, and evaluates that the first weld region is an unwelded region when the size is equal to or smaller than a first threshold value. The inspection device according to claim 1 , wherein: The processing unit evaluates the first weld region as a defective weld when the width is outside a predetermined value range.

7. The inspection device according to claim 1, wherein: The imaging unit acquires third image data obtained by imaging the second weld portion under a third condition, and fourth image data obtained by imaging the second weld portion under a fourth condition different from the third condition, wherein the second weld portion includes a third non-weld region, a fourth non-weld region, and a second weld region provided between the third non-weld region and the fourth non-weld region. The processing unit inspects the second weld portion based on a result of detecting a third boundary between the third non-weld region and the second weld region based on the third image data and a result of detecting a fourth boundary between the second weld region and the fourth non-weld region based on the fourth image data. At least one of the third condition and the fourth condition is different from the first condition and different from the second condition.

8. The inspection device according to claim 7, wherein: The first welding portion and the second welding portion are included in the inspection object, A position of the first welding portion in the inspection object is different from a position of the second welding portion in the inspection object.

9. A welding device comprising: a laser output unit for irradiating a welding object with laser light; and a control unit for controlling the laser output unit, The control unit controls the output of the laser beam based on information about an inner contour of an annular first weld region obtained from a first boundary and information about an outer contour of the annular first weld region obtained from a second boundary. The first boundary is a boundary between the first non-weld region and the first weld region, detected based on first image data obtained by imaging a first weld portion including a first non-weld region, a second non-weld region, and the first weld region under a first condition. The second boundary is a boundary between the first weld region and the second non-weld region, detected based on second image data obtained by imaging the first weld portion under a second condition different from the first condition. The annular first weld region is provided between the first and second non-weld regions, the first weld region is located outside the first non-weld region, and the second non-weld region is located outside the first weld region, and the first non-weld region is smaller than the second non-weld region. The control unit calculates a distance, i.e., a width, between the inner contour and the outer contour of the first weld region based on the first and second boundaries.

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